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Ethylene and Fruit Ripening
Abstract
The ripening of fleshy fruits represents the unique coordination of developmental and biochemical pathways leading to changes in color, texture, aroma, and nutritional quality of mature seed-bearing plant organs. The gaseous plant hormone ethylene plays a key regulatory role in ripening of many fruits, including some representing important contributors of nutrition and fiber to the diets of humans. Examples include banana, apple, pear, most stone fruits, melons, squash, and tomato. Molecular exploration of the role of ethylene in fruit ripening has led to the affirmation that mechanisms of ethylene perception and response defined in the model system Arabidopsis thaliana are largely conserved in fruit crop species, although sometimes with modifications in gene family size and regulation. Positional cloning of genes defined by ripening defect mutations in the model fruit system tomato have recently led to the identification of both novel components of ethylene signal transduction and unique transcription factor functions influencing ripening-related ethylene production. Here we summarize recent developments in the regulation of fruit ripening with an emphasis on the regulation of ethylene synthesis, perception, and response.
... Bananas, which are plucked before they are ripe, are placed in the same environment with a substance (carbide) that produces ethylene secretion and matured. The synthetically produced names for commercial ethylene are etephone or ethrel [71,72]. The most important functions of ethylene in the plant under natural conditions are as follows: (i) To ensure fruit ripening; Under the influence of ethylene, the chlorophyll in the fruit is broken down and turns into pigments, the natural color of the fruit. ...
... During ripening, starch, organic acids or oils (as in avocado) are converted into sugars. Although it is generally used in fleshy fruits such as tomatoes and bananas, it has also been used in grapes and walnuts [71,73]. (ii) It promotes aging [74]. ...
It is known that metabolic conditions such as differentiation, growth, flower and fruit formation, and development in plants are mostly organized by the plant growth regulators. These organic substances that can be made naturally in plants, control growth and other metabolic conditions related to it. They can be carried from where they occur to other parts of the plant. They can be efficient even at very small volumes and are called plant growth regulators. These are the most significant molecules affecting the subsequent plant growth and development and the internal formation of different metabolic reactions. Growth regulators were initially used only for germination of seeds and rooting of cuttings. Later, it has also been used to increase yield, product quality, and the resistance of plants against pests and diseases in the period from seed to harvest. Plant growth regulators can contribute to increasing plant resistance against diseases by stimulating the plant defense system through various physiological or biochemical reactions that occur as a result of host-pathogen interaction.
... This pattern suggests a pivotal role for JA in the initiation of fruit ripening (Kondo 2006). Furthermore, JA significantly influences fruit ripening by modulating a multitude of genes involved in this process, indicating a complex regulatory function (Barry and Giovannoni 2007;Srivastava and Handa 2005). The ripening of fruit is a highly orchestrated and genetically regulated program involving a myriad of physiological, biochemical, and developmental alterations (Paul and Pandey 2014;Bouzayen et al. 2010; Barry and Giovannoni 2007;Stepanova and Alonso 2005). ...
... Furthermore, JA significantly influences fruit ripening by modulating a multitude of genes involved in this process, indicating a complex regulatory function (Barry and Giovannoni 2007;Srivastava and Handa 2005). The ripening of fruit is a highly orchestrated and genetically regulated program involving a myriad of physiological, biochemical, and developmental alterations (Paul and Pandey 2014;Bouzayen et al. 2010; Barry and Giovannoni 2007;Stepanova and Alonso 2005). Jasmonate makes it influential to accelerate the ripening processes of both climacteric and non-climacteric fruits (Lalel et al. 2003). ...
Jasmonates, which include jasmonic acid (JA) and methyl jasmonate (MeJA), are compounds derived from linolenic acid. In recent years, the quality and phytochemical content of various fruits have been improved using plant growth regulators both before and after harvest. They play a significant role in improving the quality and biochemical composition of different fruit crops, including fruit peel colour, accumulation of anthocyanins, phenolic compounds, and antioxidant activities in the fruit. Further, the fruit ripening process is also accelerated by the application of jasmonate as it influences different physiological and molecular mechanisms of the plant system including regulation of the activities of different hormones during the entire period of fruit growth and development starting from fruit set to till ripening, activation of genes related to ripening, etc. In the case of apples, pre-harvest application of MeJA leads to enhanced fruit coloration by stimulating the anthocyanin biosynthesis gene MdUFGluT. The concentration of JA increases significantly during the early fruit development stage but then decreases sharply, reaching its lowest level when the fruits are fully ripe which signifies its role in initiating the fruit ripening process. Jasmonates can also induce the expression of genes related to ethylene synthesis and promote the production of ethylene gas. Application of jasmonates at the pre-climacteric stage increased the expression of 1-Aminocyclopropane-1-carboxylate synthase 1 (ACS 1) and 1-Aminocyclopropane-1-Carboxylic Acid Oxidase1 (ACO 1) genes. However, the accumulation of ACS1 mRNA decreased when Propyl Dihydro Jasmonate was applied at the climacteric stage, indicating that jasmonates influence system 2 ethylene synthesis pathway. In addition, these two compounds (MeJA and JA) are safe for human consumption ; hence, can be applied at the commercial level to improve the fruit quality and ripening process in different fruit crops. This review provides an overview of the recent advancements in our understanding of the regulation of jasmonate biosynthesis, and the physiological and molecular mechanisms involved in the jasmonate-mediated fruit ripening process.
... Ethylene is a hormone that plays a central role in the ripening of climacteric fruits; however, an ACC oxidase (an enzyme that participates in the synthesis of ethylene) enzyme gene has been identified in S. stellatus pitaya during ripening (Rodríguez-Irepan et al., 2011). The role of ethylene or ACC oxidase enzyme in nonclimacteric fruits is still unknown (Barry and Giovannoni, 2007), although these could participate in the ripening process or in response to the senescence process of the pitaya fruit (Barry and Giovannoni, 2007;Rodríguez-Irepan et al., 2011). ...
... Ethylene is a hormone that plays a central role in the ripening of climacteric fruits; however, an ACC oxidase (an enzyme that participates in the synthesis of ethylene) enzyme gene has been identified in S. stellatus pitaya during ripening (Rodríguez-Irepan et al., 2011). The role of ethylene or ACC oxidase enzyme in nonclimacteric fruits is still unknown (Barry and Giovannoni, 2007), although these could participate in the ripening process or in response to the senescence process of the pitaya fruit (Barry and Giovannoni, 2007;Rodríguez-Irepan et al., 2011). ...
Pitaya (Stenocereus spp.) is an exotic fruit, which has been consumed since ancient times by pre-Hispanic cultures. Recently in Mexico, this cactus has been the target of commercial attention due to the pleasant taste of their succulent fruits with juicy and sweet pulp, and a great variety of colors (white, yellow, purple and red fruits). This fruit has excellent sensory, nutritional, nutraceutical, agroindustrial and medicinal attributes; however, it has been under-utilized. The high content of betalains in this fruit allows us to consider these varieties as a source of natural pigments to be used in the food industry. The aim of this study is to show "the state of the art" of the properties of Stenocereus, to promote its study, dissemination, production, consumption and agroindustrial use. The present study shows a description of its botany, distribution, cultivation, physiology, pre and postharvest aspects, nutritional and nutraceutical composition, as well as agroindustrial and medicinal uses. The production of this fruit represents an opportunity for the economic development of some arid and semi-arid zones of Mexico due to the agronomic, nutraceutical and agroindustrial advantages. Therefore, more studies are required, mainly on physiological, nutraceutical, medicinal and agroindustrial aspects, more specifically on the non-studied species of Stenocereus, and future researches should deal with development of agro-technologies to guarantee high yields and good quality products to enable growers to make a living from it.
... Ethylene is a gaseous plant hormone that plays an important role in inducing the ripening process of fruits, especially climacteric fruits like mangoes, tomatoes, banana, apple, papaya and so forth (Barry et al., 2018). An unripe fruit generally has low levels of ethylene (Barry & Giovannoni, 2007;Lelièvre et al., 1997). As the fruit matures, ethylene is produced as a signal to induce fruit ripening (Bapat, Trivedi, et al., 2010;Barry & Giovannoni, 2007). ...
... An unripe fruit generally has low levels of ethylene (Barry & Giovannoni, 2007;Lelièvre et al., 1997). As the fruit matures, ethylene is produced as a signal to induce fruit ripening (Bapat, Trivedi, et al., 2010;Barry & Giovannoni, 2007). Ethylene production continues to increase after harvest, thus decreasing fruit shelf life, storability capacity, and increasing its susceptibility to pathogen attacks and thus increases postharvest losses (Bapat, Trivedi, et al., 2010). ...
Horticultural crops, encompassing fruits, vegetables, spices and herbs, play a critical role in providing nutrition and health‐promoting compounds. However, their limited storability challenges producers and exporters, resulting in significant postharvest losses. Traditional preservation methods like cold storage, controlled atmosphere storage and packaging techniques have been employed to prolong shelf life, but they have their constraints. Biotechnological interventions, notably genetic engineering, offer promising avenues to address these limitations. Genetic modifications target physiological processes such as ripening and ethylene production, enhancing resistance to postharvest diseases and improving nutritional profiles. For instance, genetically modified tomatoes with prolonged shelf life and reduced susceptibility to fungal infections showcase the potential of genetic engineering. Similarly, genetic modification has been successfully applied to various horticultural crops like apples, bananas and mushrooms, resulting in decreased browning and heightened disease resistance. Emerging technologies such as modified atmosphere packaging, edible coatings and nanoparticle treatments further augment efforts to extend shelf life. Despite their benefits, the debate surrounding genetically modified fruits and vegetables persists due to concerns regarding environmental impact, health implications and ethical considerations. This review offers insights into current practices and research endeavours aimed at enhancing the shelf life of horticultural crops through both traditional and biotechnological means, shedding light on opportunities and hurdles in this domain. Future directions include intensifying basic research to unravel molecular processes in harvested tissues, prioritising investigations that directly benefit consumers and developing sustainable and cost‐effective approaches for emerging technologies like modified atmosphere packaging, edible coatings and postharvest treatments.
... ETH synthesis uses methionine (Met) as the raw material, and the process is divided into three steps. First, Met is converted to S-adenosylmethionine (SAM) under the action of adenosylmethionine synthase; second, SAM is transformed into 1-aminocyclopropane-1-carboxylic acid (ACC) under the action of 1-aminocyclopropane-1-carboxylic acid synthetase (ACS); and finally, ACC is synthesized into ETH under the action of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) (Barry and Giovannoni 2007). ACS and ACO are recognized as key enzymes in ETH synthesis. ...
... In apple cultivar 'Royal Gala', antisense silencing of ACC oxidase (ACO1) resulted in no ETH synthesis, thus inhibiting fruit ripening (Schaffer et al. 2007). During ETH transduction, the receptor recognizes ETH and reduces CTR1 kinase activity, thus promoting EIN2 to activate the expression of downstream primary transcription factors (TFs) EIN3 and EIL1, and EIN3 then activates the expression of the downstream secondary TF ETH response factor (ERF), and finally realizes the transcriptional regulation of downstream genes (Barry and Giovannoni 2007). ...
Key message
Auxin (AUX) promotion of apple fruit ripening is ethylene-dependent, and AUX-MdARF17-MdERF003 plays a role in AUX-promoted ethylene synthesis in apple.
Abstract
Phytohormones play important roles in plant growth and fleshy fruit ripening, and the phytohormone auxin (AUX) can either promote or inhibit the ripening of fleshy fruits. Although AUX can influence ethylene (ETH) synthesis in apple (Malus domestica) fruits by affecting ETH system II, this mechanism remains to be explored. Here, we identified an ETH response factor (ERF) family transcription factor, MdERF003, whose expression could be activated by naphthalene acetic acid. The transient silencing of MdERF003 inhibited ETH synthesis in fruits, and MdERF003 could bind to the MdACS1 promoter. To explore the upstream target genes of MdERF003, we screened the MdARF family members by yeast one-hybrid assays of the MdERF003 promoter, and found that the transcription factor MdARF17, which showed AUX-promoted expression, could bind to the MdERF003 promoter and promote its expression. Finally, we silenced MdERF003 in apple fruits overexpressing MdARF17 and found that MdERF003 plays a role in MdARF17-promoted ETH synthesis in apple. Thus, AUX–MdARF17–MdERF003 promotes ETH synthesis in apple fruits.
... Ethylene is an important phytohormone that has a major impact on the growth and ripeness of fruits, vegetables, and ornamental plants [1][2][3][4]. Most of the ethylene comes directly from plants and agricultural products [5]. ...
... We can see that the response of this sensor shows a non-uniform rise with the number of bananas, which was relatively slow at first but became fast when the number of bananas surpassed 4. This effect indicates that ethylene emissions are mutually reinforcing [2]. To further explore the potential application of this sensor in fruit storage, they also looked at how the sensors respond to a banana ( Figure 5(aiii)) and a lemon (Figure 5(aiv)) at different stages of ripeness. ...
Ethylene, an important phytohormone, significantly influences plant growth and the ripeness of fruits and vegetables. During the transportation and storage of agricultural products, excessive ethylene can lead to economic losses due to rapid deterioration. Metal oxide semiconductor (MOS)-based chemo-resistive sensors are a promising technology for the detection of ethylene due to their low cost, high sensitivity, portability, etc. This review comprehensively summarizes the materials, fabrications, agricultural applications, and sensing mechanisms of these sensors. Moreover, the current challenges are highlighted and the potential solutions are proposed.
... in climacteric fruit, the ripening process is typically triggered by an increase in ethylene and Co 2 production (Barry & Giovannoni, 2007). analysis of ethylene production revealed that the levels were low at the start of the observation period, gradually increasing until day 7 reaching 0.18 ppm min −1 100 g FW −1 ( Figure 1F). ...
Climacteric fruits like bananas often experience significant post-harvest losses due to rapid ripening. This study investigated the molecular processes behind banana ripening, focusing on DNA methylation and its role in regulating gene expression through epigenetics. Physiological changes during ripening included alterations in peel color, fruit firmness, and total soluble solids, with marked increases in starch degradation, brown spot formation, and ethylene production by day 7. Global DNA methylation patterns, analyzed using methylation-sensitive amplification polymorphism, revealed an increase in methylation levels on day 3 of ripening. Key genes involved in DNA methylation and demethylation were identified through in silico gene and protein analysis of Musa acuminata. These include three methyltransferases (MaDRM2-A, MaDRM2-B, and MaDRM2-C) and three demethylation-related genes (MaDML-A, MaDML-B, and MaROS1). Expression levels of MaDRM2-A, MaDRM2-B, MaDML-A, and MaROS1 significantly increased by day 3, suggesting their involvement in early ripening processes. Additionally, methylation dynamics were observed on CpG islands of two critical transcription factors, MaMADS1 and MaMADS2, though gene regulation was unaffected. The study highlights that DNA methylation regulation precedes visible physiological changes in ripening, offering insights into the molecular mechanisms governing fruit ripening and potential strategies to enhance quality and extend shelf life.
... Characteristics such as peel lightening, fruit softening, and reduced resistance of the banana finger (the part we use to start peeling) can complicate post-harvest processing and transportation (Wang et al. 2018). Ethylene is well known to play a central role in the ripening of climacteric fruits like bananas, acting as a hormonal trigger that accelerates the ripening process (Barry and Giovannoni 2007). This hormone not only influences external changes, like peel color, but also affects the internal composition of the fruit, leading to altered texture, sugar content, and aroma. ...
... These biochemical and hormonal processes lead to the transition of the immature fruit into a mature and edible state (Yahia and Carrillo-Lopez 2018). Notably, the hormone ABA facilitates the accumulation of storage reserves in the kernel, while ethylene contributes to fruit ripening (Barry and Giovannoni 2007;Vahdati et al. 2008). ...
Walnut (Juglans spp.) trees hold immense significance in both economic and ecological contexts within agri-horticultural ecosystems. The comprehension of the intricate mechanisms underpinning walnut growth and development stands as a pivotal endeavor, essential for advancing sustainable yield practices. This comprehensive review delves into the multifaceted factors that contribute to the growth and development of walnuts, encompassing hormonal, biochemical, and genetic dimensions. Notably, hormones such as gibberellic acids (GAs) and sugars assume pivotal roles in the initiation and maturation of walnut flowers, with specific investigations demonstrating that the application of GAs has the capacity to augment male flower counts. The levels of endogenous auxins and gibberellins exhibit variations across distinct phases of walnut development, with the highest concentrations observed in young tissues. The molecular underpinnings of walnut growth and development involve a complex interplay of genetic regulation, hormonal dynamics, and environmental factors. Distinct sets of genes exhibit activation at discrete developmental stages, thereby influencing fundamental processes such as cell division, differentiation, and food reserve metabolism. Several key regulatory genes, including ACC, ASMT, SAD, FAD, SOC, and TFL1, emerge as pivotal orchestrators, steering essential processes encompassing cell division, differentiation, flowering, and fruit development. Conclusively, this article provides a detailed exploration of the diverse aspects of walnut growth and development, from genetic regulation to hormonal and biochemical processes. This will provide a valuable resource for researchers, horticulturalists, and biotechnologists aiming to improve walnut productivity and resilience in the face of changing environmental conditions.
... The maturation of succulent fruits involves a distinct synchronization of physiological and biochemical processes that result in alterations in color, texture, flavor, and nutritional value (Barry and Communicated by K. Barman. Giovannoni 2007). The rate of physiological activity in the majority of the apple cultivars is affected even by a very minute concentration of external ethylene exposure (Bapat et al. 2010). ...
Ethylene management and manipulating storage conditions are crucial elements that impact the postharvest quality of apple fruit. This study demonstrated the optimal approach for preserving the quality of 'Cripps Pink' apple fruit during storage by minimizing ethylene production and action, respiration rate, physiological loss of weight (PLW), and textural changes. Ethylene antagonist treatment had the greatest impact on suppressing ethylene and respiration peaks, while storage duration notably influenced fruit firmness and PLW. Fumigation treatment with 1-methylcyclopropene (MCP), 1H-cyclopropabenzene (BC), and 1H-cyclopropa[b]naphthalene (NC) effectively reduced ethylene and respiration peaks. Storage conditions (cold, controlled atmosphere, and photocatalytic oxidation) affected ethylene production and respiration, with ozonized storage showing higher rates. Prolonged storage led to increased PLW, ethylene production, and decreased fruit firmness. The most effective treatment combination for ethylene action antagonism and maintaining fruit quality was MCP treatment in ozonized cold storage for 120 d.
... The NAC family is one of the largest families of plant-specific TFs. For instance, NOR is a well-studied member of the NAC family, with the non-mature mutant (nor) being a natural mutant in tomatoes with an evident inhibition of maturation phenotype (Barry and Giovannoni, 2007). Another member, FaRIF, from the NAC (NAM, ATAF, and CUC) family has been shown to be involved in cell wall reorganization during strawberry fruit ripening, with FaRIF-RNAi mutants displaying increased fruit firmness (Martin-Pizarro et al., 2021). ...
Softening in fruit adversely impacts their edible quality and commercial value, leading to substantial economic losses during fruit ripening, long‐term storage, long‐distance transportation, and marketing. As the apple fruit demonstrates climacteric respiration, its firmness decreases with increasing ethylene release rate during fruit ripening and postharvest storage. However, the molecular mechanisms underlying ethylene‐mediated regulation of fruit softening in apple remain poorly understood. In this study, we identified a WRKY transcription factor (TF) MdWRKY31, which is repressed by ethylene treatment. Using transgenic approaches, we found that overexpression of MdWRKY31 delays softening by negatively regulating xyloglucan endotransglucosylase/hydrolases 2 (MdXTH2) expression. Yeast one‐hybrid (Y1H), electrophoretic mobility shift (EMSA), and dual‐luciferase assays further suggested that MdWRKY31 directly binds to the MdXTH2 promoter via a W‐box element and represses its transcription. Transient overexpression of ethylene‐induced MdNAC7, a NAC TF, in apple fruit promoted softening by decreasing cellulose content and increasing water‐soluble pectin content in fruit. MdNAC7 interacted with MdWRKY31 to form a protein complex, and their interaction decreased the transcriptional repression of MdWRKY31 on MdXTH2. Furthermore, MdNAC7 does not directly regulate MdXTH2 expression, but the protein complex formed with MdWRKY31 hinders MdWRKY31 from binding to the promoter of MdXTH2. Our findings underscore the significance of the regulatory complex NAC7–WRKY31 in ethylene‐responsive signalling, connecting the ethylene signal to XTH2 expression to promote fruit softening. This sheds light on the intricate mechanisms governing apple fruit firmness and opens avenues for enhancing fruit quality and reducing economic losses associated with softening.
... Ethylene plays a crucial role in modulating many processes during the ripening of climacteric fruits, including the regulation of metabolite changes that contribute to post-harvest fruit quality changes (Mubarok et al. 2016;Anas et al. 2022). The fruit ripening process is directly associated with several metabolic changes in fruits, including changes in fruit color, softening, texture, aroma, volatile, compounds, sugar content, secondary metabolite content, and susceptibility to pathogens (Barry and Giovannoni 2007). The nutrient content is an important factor in determining the quality of tomato fruit. ...
Tomato with prolonged fruit shelf life and improved postharvest quality would be an interesting commodity for breeders and consumers. A weak ethylene receptor mutant of experimental tomato, Sletr1-2, exhibits extended fruit shelf life without any undesirable pleiotropic effects. In this study, we elucidate the impact of Sletr1-2 mutation on the plant growth and fruit quality of the near-isogenic line containing the Sletr1-2 locus (NIL-Sletr1-2) under the genetic background of commercial tomatoes. The heterozygote line of BC3F1 and homozygote line of BC3F1, NIL-Sletr1-2 were generated by crossing the original Sletr1-2 mutant with commercial tomato cultivar ‘Intan’ and backcrossed three times. The plant growth and fruit quality were evaluated to identify the impact of Sletr1-2 mutation on NIL-Sletr1-2. The results showed that NIL-Sletr1-2 resulted in a longer fruit shelf life compared to BC2F1 and also ‘Intan’ while they have a smaller fruit size compared to BC3F1 and also resulted in orange-color fruit. These results indicate that Sletr1-2 mutation has favorable impacts on the postharvest quality of NIL-Sletr1-2 tomato fruit, resulting in improving fruit shelf-life, but still producing a smaller fruit size.
... For allowing camouflage of itself with leaves, a fruit must be unattractive and of green color. The ripening of fruits is a unique coordination of various biochemical and developmental pathways regulated by ethylene, which affects texture, nutritional quality, color and aroma of fruits (Barry and Giovannoni, 2007). The ethylene regulates firmness and color changes involving reduction in chlorophyll, increase in carotenoids or anthocyanins, sugars and biosynthesis of volatile organic compounds (VOCs) during ripening in climacteric fruits. ...
The present study was conducted with the aim of verifying secondar metabolites amplification from the second generation of Phyllanthus odontadenius (P. odontadenius M2) obtained by seeds gamma-rays (Cs-137) irradiation and their effects on Plasmodium falciaprum. The obtained M1 plantlets come from to original seeds from a single plant of P. odontadenius ikrradiated at 150 Gy with Conservatome LISA I Irradiator. These plantes cultivated previously in vitro on MS (Murashige and Skoog) medium were cultivated in the field and which the randomized plants gave seeds which were used to obtain the M2 plants of P. odontadenius. The phytochemical screening of P. odontadenius M2 extracts (aqueous and methanolic extracts) carried out at LACOREN and the aqueous extract in vitro antiplasmodial activity determination carried out at INRB should justify this secondary metabolites amplification of P. odontadenius Plants M2. On the one hand, results showed that sencondary metabolites of both aqueous and methanolic extracts were amplified compared to those obtained previously. On the other hand, the in vitro antiplasmodial activity of aqueous extracts was found to be high (IC50<5 µg/ml) according to WHO recommendation's. This would be a valuable reason for the peaceful use of ionizing radiation in the fight against malaria and which would validate the use of P. odontadenius and its improvement by mutagenesis techniques.
Keywords: Malaria, Phyllanthus odontadenius, Gamma rays, secondary metabolites; in vitro antiplasmodial activity.
... Fleshy fruit development and ripening involve many changes in the fruit growth including size as well as flavor, and aroma (Barry and Giovannoni 2007;Bapat et al. 2010;Plant Growth Regulation 2019a). In general, cytokinins (CKs) play significant roles during the early stages after pollination, while auxins and gibberellins are mainly involved in cell expansion stages (Gillaspy et al. 1993;Srivastava and Handa 2005). ...
Molecular regulation of fruit ripening is fundamental for sustainable production of quality fruits with desired traits. Ethylene and abscisic acid (ABA) are two of the most studied plant hormones during fruit development, onset, and progression of fruit ripening, while the abundance and role(s) of other phytohormones have remained elusive. Here, we used high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify endogenous concentrations of numerous plant hormones, namely cytokinins (CKs), auxins, gibberellins, jasmonates, ABA and salicylic acid (SA), as well as their pathway metabolites during tomato fruit development and ripening. Changes in the levels of 47 compounds including active phytohormones and their derivatives during fruit development (stages Dev1, Dev2 and Dev3) and ripening (stages mature green, breaker, breaker + 3 d and breaker + 8 days) of tomato fruit were identified. Quantitative multivariant analyses of the phytohormones and their related compounds involving the seven analyzed stages showed their differential accumulation during fruit development and ripening. Early developmental stage (Dev1) of cell number proliferation was associated with auxins (IAA-GE, IAA-Glu, OxIAA-GE, OxIAA, and OxIAA-Asp), trans-zeatin (tZ)-, dihydrozeatin (DZ)- and N⁶-(∆²-isopentenyl) adenine (iP)-type CKs (tZ7G, tZ9G, tZRMP, tZOG, DZOG, iP7G, iP9G), jasmonic acid (JA)-isoleucine, and gibberellin GA29. The cell expansion phase, Dev2, was found associated with auxins IAA-Asp and I3A, gibberellins GA19 and GA20, JA, SA and phenylacetic acid. Abundance of ABA and benzoic acid at the maturation phase (Dev3), mature green and breaker stages of fruit development were apparent. At the fruit ripening phase (BR + 3 and BR + 8) accumulation of iP-, cis-zeatin (cZ)-, tZ-, DZ-type CKs (iP, iPR, iPRMP, cZR, cZ7G, cZROG, cZRMP, tZR, tZROG, DZR, DZRMP) and CK methylthioderivatives (MeS-Z, MeS-ZR), auxin IAM, and jasmonates DiH-JA and JA-Me was apparent. Notably, the mevalonate CK pathway cZRMP→cZR→cZ was found to be the dominant pathway during fruit ripening, which contrasts with the known CK abundances in non-climacteric fruits. Taken together, these results provide a map of the differential accumulation of phytohormones and their metabolites during the development and ripening of fleshy tomato fruit.
... These changes are influenced by various environmental factors, biological and abiotic stresses, as well as genetic regulation [4]. Ethylene can promote fruit ripening, regulate gender differentiation, and respond to biotic and abiotic stresses [5]. Studies have found that exogenous ethylene treatment can increase cell membrane permeability in papaya fruit and kiwifruit, accelerating fruit ripening and softening [6]. ...
‘Ruixue’ apples were used as the test material to study the effect of 10 μM methyl jasmonate (MeJA) on the quality and cell wall metabolism of apples after 18 d of storage. The results showed that MeJA significantly decreased the respiratory rate, reduced the titratable acid content and maintained a high soluble solids content. MeJA has been shown to suppress the activities and gene expressions of WSP, CSP, ISP, and cellulose in contrast to the control group, thereby maintaining a lower cell permeability and higher exocarp firmness. MeJA significantly decreased the expression of MdACS, MdACO, MdPL, Mdgal, and MdPG genes in the apple exocarp when compared to the control group. In addition, the overexpression of MdPL18 increased the content of cell wall polysaccharides such as WSP and CSP, enhanced cell wall-degrading enzyme activities, and accelerated fruit ripening and softening, whereas silencing MdPL18 did the opposite. Together, these results demonstrate that exogenous MeJA maintains the Ruixue apple fruit quality by regulating the metabolism of cell wall substances.
... 'Colorpple' ('Yoko' × 'Senshu') and 'Manhong' ('Hongso' × 'Gamhong') are new apple cultivars which have been recently registered in Korea for commercial production, in 2019 and 2022, respectively. Generally, while apples can be stored for a relatively long time, they are climacteric fruits, meaning that the plant hormone ethylene regulates their ripening and postharvest preservation (Barry and Giovannoni, 2007). Thus, controlling ethylene production is an appealing strategy for delaying ripening and preserving the quality of apples after harvest. ...
Methods by which to realize the postharvest preservation of the new apple cultivars ‘Colorpple’ and ‘Manhong’ are unknown. Hence, the objective of this study was to evaluate the effects of 1-methylcyclopropene (1-MCP) on the postharvest physiological characteristics and storage quality of ‘Colorpple’ and ‘Manhong’ apples. Harvested apples were treated with 1-MCP (1 µL·L-1) and stored for 40 days under warm temperature (20 ± 1°C) and for eight months under cold (0 ± 1°C) temperature conditions. Untreated fruits were used as control groups. Ethylene production and respiration rates were lower in all treated fruits stored at a warm temperature. However, 1-MCP had minimal effects on flesh firmness, weight loss, or the soluble solid content (SSC), affecting only the titratable acidity (TA) at 40 days. Higher L* (20 and 30 days) and lower a* (30 and 40 days) values were observed only in the fruit skins of untreated ‘Colorpple’ apples. Additionally, skin greasiness
increased in the untreated ‘Colorpple’ (30 and 40 days) and ‘Manhong’ (20 days) apples. Slight levels of fruit decay were observed in ‘Colorpple’ (30 days) and ‘Manhong’ (30 and 40 days). At a cold temperature, 1-MCP induced lower ethylene production and respiration rates and higher flesh firmness and TA in both cultivars, while weight losses as well as skin color and SSC changes were not detected. A lower SSC/TA ratio was observed in treated fruits after 6-8 months of storage.
Moderate to severe skin greasiness was observed in both untreated apple types. Overall, this study suggests that a 1-MCP treatment improves the postharvest physiological characteristics and fruit quality of ‘Colorpple’ and ‘Manhong’ apples; 1-MCP is more effective for long-term storage of these cultivars at cold temperatures but is less effective at ambient temperatures.
... This decrease in LeACS1 expression may have implications for the prolonged ripening process and subsequently affect the duration of fruit firmness. Throughout the ripening process, ACS and ACO genes play a crucial role in regulating ethylene production, and they contribute to the progressive changes related to fruit ripening and the subsequent softening of the fruit (Barry et al., 2000;Barry & Giovannoni, 2007). The current study highlights the low gene expression patterns related to ethylene production in the Sakura F1 cultivar, which can be utilized in breeding programs of tomatoes to realize core cultivars with an extended shelf-life duration. ...
... Transcription factors are pivotal in the regulation of fruit ripening. Studies have highlighted the significance of factors like RIN and NOR as key regulators of tomato fruit ripening, influencing the expression of numerous ripening-related genes through both ethylene-dependent and -independent pathways [1,37,38]. Additionally, other transcription factors such as CNR, AP2a, NAC4, and FUL are known to play crucial roles in tomato fruit ripening [1]. Recently, several novel transcription factors have been identified as participating in the regulation of tomato fruit ripening. ...
Fruit ripening is controlled by internal factors such as hormones and genetic regulators, as well as external environmental factors. However, the impact of redox regulation on fruit ripening remains elusive. Here, we explored the effects of L-cysteine hydrochloride (LCH), an antioxidant, on tomato fruit ripening and elucidated the underlying mechanism. The application of LCH effectively delayed tomato fruit ripening, leading to the suppression of carotenoid and lycopene biosynthesis and chlorophyll degradation, and a delayed respiration peak. Moreover, LCH-treated fruit exhibited reduced hydrogen peroxide (H2O2) accumulation and increased activities of superoxide dismutase (SOD), catalase (CAT), and monodehydroascorbate reductase (MDHAR), compared with control fruit. Furthermore, transcriptome analysis revealed that a substantial number of genes related to ethylene biosynthesis (ACS2, ACS4, ACO1, ACO3), carotenoid biosynthesis (PSY, PDS, ZDS, CRTISO), cell wall degradation (PG1/2, PL, TBG4, XTH4), and ripening-related regulators (RIN, NOR, AP2a, DML2) were downregulated by LCH, resulting in delayed ripening. These findings suggest that the application of LCH delays the ripening of harvested tomato fruit by modulating the redox balance and suppressing the expression of ripening-related genes.
... Tomato, a climacteric fruit, necessitates an increased ethylene output at the onset of ripening (Alexander and Grierson 2002;Alba et al. 2005; Barry and Giovannoni 2007;Li et al. 2019). Inhibiting ethylene biosynthesis or its perception adversely affects the rate of ripening (Theologis 1992). ...
An intrinsic and genetically determined ripening program of tomato fruits often depends upon the appropriate activation of tissue- and stage-specific transcription factors in space and time. The past two decades have yielded considerable progress in detailing these complex transcriptional as well as hormonal regulatory circuits paramount to fleshy fruit ripening. This non-linear ripening process is strongly controlled by the MADS-box and NOR family of proteins, triggering a transcriptional response associated with the progression of fruit ripening. Deepening insights into the connection between MADS-RIN and plant hormones related transcription factors, such as ERFs and ARFs, further conjugates the idea that several signaling units work in parallel to define an output fruit ripening transcriptome. Besides these TFs, the role of other families of transcription factors such as MYB, GLK, WRKY, GRAS and bHLH have also emerged as important ripening regulators. Other regulators such as EIN and EIL proteins also determine the transcriptional landscape of ripening fruits. Despite the abundant knowledge of the complex spectrum of ripening networks in the scientific domain, identifying more ripening effectors would pave the way for a better understanding of fleshy fruit ripening at the molecular level. This review provides an update on the transcriptional regulators of tomato fruit ripening.
... Ethylene, a gaseous plant hormone, often plays an important regulating role in the growth and development of fruit and vegetables (Barry and Giovannoni, 2007). This hormone is made by fresh produce at different rates. ...
... Therefore, further research is needed to select suitable reference genes under different stress conditions. FaMYB10, a member of the R2R3-MYB transcription factor family, exerts a pivotal role in anthocyanin biosynthesis in strawberry fruit [44,45] . Previous studies and transcriptome data revealed that FaMYB10 predominantly exhibits expression during the TR and R stages of strawberry fruit development, thereby verifying the reliability of the selected reference genes. ...
The rapid, reliable, and efficient characteristics of quantitative reverse transcription polymerase chain reaction (qRT-PCR) make it a highly advantageous method for assessing gene expression levels. The identification of stable reference genes is crucial for successful gene expression studies. Cultivated strawberry fruit has been extensively investigated as a model for studying the non-climacteric fruit ripening process. However, more research needs to be conducted on identifying suitable reference genes at different developmental stages of strawberry fruit. We selected the 'Yanli' and 'Chuliandeweidao' cultivars to screen potential reference genes in various tissues, organs, and developmental stages of strawberry fruit. Based on the analysis of high-quality haplotype-resolved genome and transcriptomic FPKM data, FaADPrf1 (ADP-ribosylation factor 1), FaGAPC2 (Glyceraldehyde-3-phosphate dehydrogenase), FaPPC1 (Peptidyl-prolyl cis-trans isomerase 1), and FaEF1-α (Elongation factor 1-alpha) were selected as candidate reference genes, along with the commonly used Fa26S rRNA, for normalization purposes. A qRT-PCR analysis showed 89.21% to 101.51% amplification efficiency for five candidate reference genes, with correlation coefficients (R²) exceeding 0.99. Reference genes' expression stability was assessed using GeNorm, NormFinder, BestKeeper, and Comparative delta-Ct method. RefFinder analysis determined that FaGAPC2 and FaADPrf1 were the most suitable reference genes, considering the results obtained from the abovementioned four methods. The calculated results were validated by studying the expression of FaMYB10, FaUGT1, and FaCHS in different developmental stages of 'Yanli' fruit. This validation confirmed that both FaGAPC2 and the combination of FaGAPC2 and FaADPrf1 could serve as suitable reference genes, with the combination of FaGAPC2 and FaADPrf1 being more suitable than the single FaGAPC2 in certain cases. In summary, we obtained suitable reference genes for research on cultivated strawberry fruit development, which will benefit further study on the ripening of non-climacteric fruits.
... However, it has been found that the development of leaves and flower stems were affected by the presence of ethylene and other phytohormones, such as auxins, gibberellins and cytokinins (Iqbal et al., 2017). Several studies have shown that in Arabidopsis plants treated with AVG, ethylene promoted cell division, increasing stem mass, except for plants exposed to environmental stress, where ethylene had a negative effect on the cell cycle (Barry and Giovannoni, 2007;Dubois et al., 2018). ...
Objective: To evaluate the effect of aminoethoxyvinylglycine (AVG) additions on several growth variables of R. asiaticus in a greenhouse under a typically dry environment of the Mexicali valley. Design/methodology/approach: The variables determined were, bud opening rate, flower diameter, height of stem and bud growing rate and completely randomized block experimental design under a 2 by 4 factorial arrangement and three replicates was used for setting up the treatments with rates AVG of 0,100,150 and 200ppm over La Belle Deep Rose (DER) and La Belle Dark Orange (DAR) R. asiaticus cultivars. Results: The optimal dose of AVG for reducing flower bud diameter on both cultivars were those of 200 and 100 ppm respectively. Also, AVG addition had a significant effect in reducing stem height and growing rate for both cultivars. Limitations on study/implications: The use of AVG has shown good results as inhibitor of ethylene synthesis and extension of shelf life in carnations, snap dragons (Antirrhinum), ripening of fruits, and to reduce abortion of female flowers in certain species of walnuts, so, based on the above and considering the lack of information regarding the use of AVG inhibitor in the opening of Persian Buttercup flower buds was used AVG in R. asiaticus. Findings/conclusions: AVG addition on plants of R. asiaticus had a significant effect reducing growth, both in diameter and height in the La Belle Deep Rose (DER) and La Belle Dark Orange (DAR) varieties
Nitrogen (N) is vital for mango yield and fruit quality, but finding the optimal amount is crucial to avoid the ‘stay green’ problem, which diminishes both fruit quality and profitability. This study aimed to assess the impact of N levels on the fruit quality and yield of ‘Kensington Pride’ (‘KP’) mangoes and determine the amount of N that triggers the ‘stay green’ effect in fruit. A field trial was conducted in a commercial orchard with N treatments (0, 12.5, 25, and 50 kg ha−1) and four replications during the 2018 and 2019 cropping seasons. Fruit yield was quantified, and post-harvest quality (skin color during ripening, sugar content [°Brix], and texture) as well as ethylene effects were assessed. Fruit yields did not vary among N levels over the two cropping seasons but were significantly lower in 2018 (20.0 t ha−1) compared to 2019 (38.5 t ha−1), illustrating the alternate year-bearing habit of ‘KP’ mangoes. In the 2018 harvest, fruit from trees receiving 25 kg N ha−1 appeared yellow–green compared to those with less N, while fruit from trees with 50 kg N ha−1 exhibited ‘stay green’ skin, indicating that applications of 25 and 50 kg N ha−1 were excessive. There was no ‘stay green’ skin observed in the 2019 harvest, indicating that the environment may also be a contributing factor. The texture of ripe fruit from untreated control trees had the highest flesh resistance. Moreover, ethylene-treated fruit ripened in nine days post-harvest and had significantly lower sugar content than untreated fruit, which ripened in 14 days. This study provides valuable insights into the complex interactions among N application, fruit quality, and yield of ‘KP’ mangoes, highlighting the importance of appropriate N management for a sustainable and environmentally friendly commercial mango production system.
The increasing global population has heightened the demand for food, leading to escalated food production and, consequently, the generation of significant food waste. Factors such as rapid ripening, susceptibility to physiological disorders, and vulnerability to microbial attacks have been implicated as contributing to the accelerated senescence associated with food waste generation. Fruits and vegetables, characterized by their high perishability, account for approximately half of all food waste produced, rendering them a major area of concern. Various postharvest technologies have thus been employed, including the application of phytohormone treatments, to safeguard and extend the storability of highly perishable food products. This review, therefore, explores the physicochemical properties and biological aspects of phytohormones that render them suitable for food preservation. Furthermore, this review examines the effects of externally applied phytohormones on the postharvest physiology and quality attributes of fresh produce. Finally, the review investigates the mechanisms by which exogenous phytohormones preserve food quality and discusses the associated limitations and safety considerations related to the use of these compounds in food applications.
Biochar samples derived from various agricultural wastes including corn cobs, corn straws, rice husks, and rice
straws were investigated for potential use as ethylene absorbers to delay ‘Gros Michel’ banana ripening. The
biochar samples were prepared using the pyrolysis method at 500 ◦C with a heating rate of 1 ◦C/min for 2 h and
examined for their morphology, surface area, pore diameter, pore volume, functional groups, CHNS/O composition,
elemental composition, and thermal properties. Each type of biochar had different elemental compositions
and surface area. The largest surface area of 110.67 m2/g was found in rice husk biochar. The ethylene
adsorption efficiency was determined in closed containers and low-density polyethylene (LDPE) bags containing
‘Gros Michel’ bananas treated with different biochar types. The rice husk biochar exhibited ethylene adsorption
of 31.14 % in closed containers at 144 h and the low total color difference ΔE value of 22.30. Thus, rice husk
biochar showed promise as an ethylene absorber to delay fruit ripening in packaging applications.
1.
Ethylene is an important phytohormone that orchestrates a multitude of physiological and biochemical processes regulating fruit ripening, from early maturation to post-harvest. This review offers a comprehensive analysis of ethylene’s multifaceted roles in climacteric fruit ripening, characterized by a pronounced increase in ethylene production and respiration rates. It explores potential genetic and molecular mechanisms underlying ethylene’s action, focusing on key transcription factors, biosynthetic pathway genes, and signal transduction elements crucial for the expression of ripening-related genes. The varied sensitivity and dependency of ripening traits on ethylene are elucidated through studies employing genetic mutations and ethylene inhibitors such as AVG and 1-MCP. Additionally, the modulation of ripening traits by ethylene is influenced by its interaction with other phytohormones, including auxins, abscisic acid, gibberellins, jasmonates, brassinosteroids, and salicylic acid. Pre-harvest fruit drop is intricately linked to ethylene, which triggers enzyme activity in the abscission zone, leading to cell wall degradation and fruit detachment. This review also highlights the potential for applying ethylene-related knowledge in commercial contexts to enhance fruit quality, control pre-harvest drop, and extend shelf life. Future research directions are proposed, advocating for the integration of physiological, genetic, biochemical, and transcriptional insights to further elucidate ethylene’s role in fruit ripening and its interaction with other hormonal pathways.
In 2021, world fruit and vegetable production including roots and tubers reached ca. 2060 million tonnes. The total fruit production reached 910 million tonnes, and banana was the most produced fruit (125 million tonnes) followed by watermelons (102 million tonnes), apples (93 million tonnes), oranges (76 million tonnes), and grapes (74 million tonnes). The global production of vegetables reached 1150 million tonnes and tomatoes was the most produced vegetable with 189 million tonnes, followed by onions including shallots (107 million tonnes), cucumbers including gherkins (93 million tonnes), cabbages (71 million tonnes), and eggplants (59 million tonnes) (FAO, 2021).
In this study, a dual‐mode sensing biopolymer membrane employing chitosan (CS), polyvinyl alcohol (PVA), and ammonium molybdate (AM) was developed for optical and electrochemical detection of ethylene. The biopolymer composite was characterized by X‐ray diffraction (XRD), Fourier transform infra‐red (FTIR), and scanning electron microscopy (SEM).The relationship between ethylene concentration and optical/electrochemical response was investigated. XRD analysis showed enhanced ionic conduction, supported by SEM images showing uniform pore distribution within the synthesized membrane, facilitating effective gas interaction with Molybdenum. The increased FTIR peak intensities with higher amount of molybdenum in the membrane indicates enhanced molecular interactions. Applied to a microelectrode chip, the membrane exhibits a measurable electrochemical response with oxidation peak appearing in cyclic voltammogram as Molybdenum ions undergo reduction upon ethylene exposure. Colorimetric measurements, based on CIELAB values, reveals visible color shift with increasing ethylene concentrations, particularly at 10% molybdenum impregnation. Ionic conductivity and total color difference exhibit parallel variation with ethylene concentrations. X‐ray photoelectron spectroscopy confirms molybdenum oxidation state shift from +6 to +5 in the membrane upon ethylene interaction. The inexpensive colorimetric method enables direct color change visualization in practical applications. The resulting dual‐functional biopolymer membrane shows adaptability and versatility by responding to both optical and electrochemical signals.
Flesh firmness is a critical breeding trait that determines consumer selection, shelf life, and transportation. The genetic basis controlling firmness in apple (Malus×domestica Borkh.) remains to be fully elucidated. We aimed to decipher genetic variance for firmness at harvest and develop potential molecular markers for marker-assisted breeding. Maturity firmness for 439 F1 hybrids from a cross of ‘Cripps Pink’ and ‘Fuji’ was determined in 2016 and 2017. The phenotype segregated extensively, with a Gaussian distribution. In a combined bulked segregant analysis (BSA) and RNA-sequencing analysis, eighty-four differentially expressed genes were screened from the 10 QTL regions. Interestingly, next-generation re-sequencing analysis revealed a Harbinger-like transposon element insertion upstream of the candidate gene PECTATE LYASE5 (MdPL5); the genotype was associated with flesh firmness at harvest. The presence of this transposon repressed MdPL5 expression and was closely linked to the extra-hard phenotype. MdPL5 was demonstrated to promote softening in apples and tomatoes. Subsequently, using the MdPL5 promoter as bait, MdNAC1-L was identified as a transcription activator that positively regulates ripening and softening in the developing fruit. We also demonstrated that MdNAC1-L could induce the up-regulation of MdPL5, MdPG1, and the ethylene-related genes MdACS1 and MdACO1. Our findings provide insight into TE-related genetic variation and the PL-mediated regulatory network for the firmness of apple fruit.
ACO (1-aminocyclopropane-1-carboxylic acid) serves as a pivotal enzyme within the plant ethylene synthesis pathway, exerting influence over critical facets of plant biology such as flowering, fruit ripening, and seed development.
This study aims to identify ACO genes from representative Rosaceae genomes, reconstruct their phylogenetic relationships by integrating synteny information, and investigate their expression patterns and networks during fruit development.
we utilize a specialized Hidden Markov Model (HMM), crafted on the sequence attributes of ACO gene-encoded proteins, to systematically identify and analyze ACO gene family members across 12 representative species within the Rosaceae botanical family. Through transcriptome analysis, we delineate the expression patterns of ACO genes in six distinct Rosaceae fruits.
Our investigation reveals the presence of 62 ACO genes distributed among the surveyed Rosaceae species, characterized by hydrophilic proteins predominantly expressed within the cytoplasm. Phylogenetic analysis categorizes these ACO genes into three discernible classes, namely Class I, Class II, and Class III. Further scrutiny via collinearity assessment indicates a lack of collinearity relationships among these classes, highlighting variations in conserved motifs and promoter types within each class. Transcriptome analysis unveils significant disparities in both expression levels and trends of ACO genes in fruits exhibiting respiratory bursts compared to those that do not. Employing Weighted Gene Co-Expression Network Analysis (WGCNA), we discern that the co-expression correlation of ACO genes within loquat fruit notably differs from that observed in apples. Our findings, derived from Gene Ontology (GO) enrichment results, signify the involvement of ACO genes and their co-expressed counterparts in biological processes linked to terpenoid metabolism and carbohydrate synthesis in loquat. Moreover, our exploration of gene regulatory networks (GRN) highlights the potential pivotal role of the GNAT transcription factor (Ejapchr1G00010380) in governing the overexpression of the ACO gene (Ejapchr10G00001110) within loquat fruits.
The constructed HMM of ACO proteins offers a precise and systematic method for identifying plant ACO proteins, facilitating phylogenetic reconstruction. ACO genes from representative Rosaceae fruits exhibit diverse expression and regulative patterns, warranting further function characterizations.
Tomato fruit colors are directly associated with their appearance quality and nutritional value. However, the tomato fruit color formation is an intricate biological process that remain elusive. In this work, we characterized a tomato yellow fruited tomato 3 (yft3, e9292, Solanum lycopersicum) mutant with yellow fruits. By the map-based cloning approach, we identified a transversion mutation (A2117C) in YFT3 gene encoding a putative isopentenyl diphosphate isomerase (SlIDI1) enzyme which may functions in the isoprenoid biosynthetic pathway by catalyzing conversion between isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The mutated YFT3 (A2117C) (designated to YFT3 allele) and the YFT3 genes did not show expression difference at protein level, and their encoded YFT3 allele (S126R) and YFT3 proteins were both localized in plastids. However, the transcript levels of eight genes (DXR, DXS, HDR, PSY1, CRTISO, CYCB, CYP97A, and NCED) associated with carotenoid synthesis were up-regulated in fruits of both yft3 and YFT3 knockout (YFT3-KO) lines at 35dpa and 47dpa compared to the red-fruit tomato cultivar (M82). The in vitro and in vivo biochemical analyses indicated YFT3(S126R) possessed much lower enzymatic activities than the YFT3 protein, indicating that S126R mutation can impair YFT3 activity. The molecular docking analysis showed that YFT3 allele has higher ability to recruit IPP, but abolishes attachment of the Mg2+ cofactor with IPP, suggesting that Ser126 is a critical residue for YTF3 biochemical and physiological functions. As a result, the yft3 mutant tomato line has low carotenoid accumulation and abnormal chromoplast development, which results in the yellow ripe fruits. This study provides new insights into molecular mechanisms of tomato fruit color formation and development.
Recent advances in active food packaging have been driven by the integration of electrospun materials, exploiting their inherent advantages. Electrospun materials can be easily functionalized with antioxidant, antibacterial, antifungal, and sensory additives, as well as ethylene scavengers and CO2 emitters making them ideal for active food packaging. However, it's worth noting that certain electrospun materials utilized in this context are derived from petroleum-based synthetic polymers, which may raise environmental concerns post-usage. In this regard, the use of sustainable polymers for electrospun food packaging materials can address problems like waste generation and the environmental impact of traditional synthetic, petroleum-based polymers. Central to this transition is the utilization of biomass-derived polymers sourced from renewable sources like plants, algae, microorganisms, and wastes. Sustainable polymers, such as poly(lactic acid) (PLA), starch, cellulose and derivatives, polyhydroxyalkanoates (PHA), chitosan, gelatin, and zein have emerged as key sustainable players in active food packaging. This review provides a comprehensive overview of electrospun materials of sustainable polymers derived from biomass for the development of active food packaging films. The review begins with a brief description of the fundamentals and process for active food packaging and electrospinning, followed by a detailed examination of the applications of electrospun materials for active food packaging, categorized by polymer type and bioactivity. Finally, the review concludes with current challenges and provides insights into future perspectives in this area.
The aim of this study was to develop a porous carbon/polypropylene composite to evaluate as a novel refrigerator drawer in order to extend the shelf life of fruit and vegetables. For this purpose, walnut shells and oak wood chips were chosen as precursors to produce activated carbon via physical activation method, and oak wood chips were used to produce bio-char. Carbon samples and polypropylene were utilized to obtain porous composite without any binder agent. It was determined that the composite samples formed by adding 0.1% to 10% activated carbon to polymer matrix showed similar mechanical properties compared to the pure PP drawer. These findings suggests that the shelf life of fruit and vegetables in the porous drawer increased at least 1.5 to 2 times compared to the PP drawer, as a result of the ethylene gas adsorption onto activated carbon. The activated carbon/polypropylene porous composite production process which was explained in this study and the implementation of the refrigerator drawer was patented (Publication Number: WO 2023/025471 A1) by Bosch-Siemens Home Appliances (BSH) GmbH.
Hortikultura merupakan istilah yang telah lama dikenal oleh masyarakat luas, bahkan di luar negeri istilah ini telah di kenal sejak abad 17 silam, yang berawal dari Italia dan Eropa Tengah. Tanaman hortikultura terpisah dari jenis tanaman pangan, tanaman perkebunan, tanaman industri dan tanaman lainnya. Hal ini dikarenakan jenis tanaman hortikultura berfungsi dan bersifat lain. Istilah hortikultura merupakan gabungan dari bahasa latin, hortus yang berarti kebun dan culture yang berarti bercocok tanam. Secara harfiah, hortikultura berarti ilmu yang mempelajari pembudidayaan tanaman di kebun atau di sekitar tempat tinggal ataupun di lahan pekarangan. Beberapa pakar mendefinisikan hortikultura sebagai ilmu yang mempelajari budidaya tanaman buah-buahan, sayur-sayuran dan tanaman hias. Saat ini pengertian hortikultura tidak hanya terbatas pada budidaya di kebun, tetapi berkembang lebih luas lagi, yakni mencakup juga budidaya di luar halaman rumah. Bahkan banyak usahawan yang menekuni bidang ini, dengan menggunakan area yang cukup luas baik secara tradisional maupun modern. Usaha pengembangan hortikultura akhir-akhir ini mendapat perhatian yang lebih serius untuk menunjang program pembangunan perekonomian negara. Sebagai konsekuensi dari adanya peningkatan pendapatan, penambahan penduduk, meningkatnya kesadaran gizi masyarakat, permintaan akan buah-buahan, sayuran dan tanaman hias juga menunjukkan peningkatan yang cukup pesat.
In this chapter, we deal with the change from the exception to the rule in biological systems, both by the action of nature and by the changes that occur due to human action. We talk about the origin of life on planet Earth, the first organisms that colonized primitive environments and changed the atmosphere, giving rise to new forms of life, the appearance of eukaryotic, multicellular organisms, and the different forms of reproduction. We focus on events and changes that were initially considered teratological and that are familiar to our current vision. We also mention adaptations, plasticity, and different phenotypes that became advantages and allowed organisms to continue living in different environments. On the other hand, we point to global processes that affect humans and that in many cases are caused by humans. We discuss examples of diseases that turn into pandemics, the processes of environmental pollution, and accelerated climate change. Finally, we will discuss the changes in scientific ideas, which are closely linked to the social context at each moment in human history, the changes in the different fields of study and within society itself.
The peel colour of fruit is one of the most vital quality elements that affects fruit marketability and consumer acceptability. Citrus early varieties and native species generally reach internal maturity with minimum eating quality prior to the onset of colour break, i.e., when the natural colour development is relatively weak and insufficient. Similarly, to avoid any weather inclement or to extend the market, the fruits were harvested early with poor appearance. In such cases, degreening techniques were used to accelerate the colour transition of fruits from green to a desirable colour and to enhance their marketability. Exogenous ethylene degreening has effectively accelerated the external colour development of fruits by triggering ripening-related processes, most notably the breakdown of chlorophyll pigments and the accumulation of carotenoids in citrus peel tissue. The majority of citrus varieties respond favourably to preharvest degreening with ethephon; however, post-harvest degreening is commercially followed in citrus. The major factors affecting degreening processes are the preharvest factors (including fruit maturity stages, tree vigour, climatic effects, and cultural practices) and the post-harvest factors (i.e., atmospheric conditions and packinghouse treatments). The ethylene degreening exposure not only results in desirable appearance and quality improvements to fruit, but it may also have adverse consequences associated with hastened fruit senescence. However, the sensitivity of fruits to calyx senescence varies according to the variety, preharvest situations, and processing characteristics. Therefore, the degreening needs to be carried out in the correct environment for a desirable quality.
The potential to transform the agriculture sector and reduce food waste significantly lies in the ability to assess the quality of fruits and vegetables on a large scale. This article introduces AgriTera, an innovative solution that utilizes sub-terahertz wireless signals for accurate and non-invasive fruit ripeness sensing, without the need for physical contact. The underlying idea is that sugar and water concentrations in fruits, linked to ripening, create distinctive patterns in the wideband spectrum of reflected signals from the fruit body. AgriTera leverages the sub-THz bands due to their wide bandwidth, sensitivity to water, millimeter-scale penetration depth, and non-ionizing features. This enables high-resolution inferences from both the peel and pulp underneath. A chemometric model is developed to translate reflection spectra into well-known ripeness metrics like Dry Matter and Brix. Extensive over-the-air experiments using commercial sub-THz transceivers are conducted and compared with ground truth values from specialized sensors and a vision-based scheme.
Fruit ripening is a complex process involving dynamic changes to metabolites and is controlled by multiple factors, including transcription factors (TFs). Several TFs are reportedly essential regulators of tomato (Solanum lycopersicum) fruit ripening. To evaluate the effects of specific TFs on metabolite accumulation during fruit ripening, we combined CRISPR/Cas9-mediated mutagenesis with metabolome and transcriptome analyses to explore regulatory mechanisms. Specifically, we generated various genetically engineered tomato lines that differed regarding metabolite contents and fruit colors. The metabolite and transcript profiles indicated that the selected TFs have distinct functions that control fruit metabolite contents, especially carotenoids and sugars. Moreover, a mutation to ELONGATED HYPOCOTYL5 (HY5) increased tomato fruit fructose and glucose contents by approximately 20% (relative to the wild-type levels). Our in vitro assay showed that HY5 can bind directly to the G-box cis-element in the Sugars Will Eventually be Exported Transporter (SWEET12c) promoter to activate expression, thereby modulating sugar transport. Our findings provide insights into the mechanisms regulating tomato fruit ripening and metabolic networks, providing the theoretical basis for breeding horticultural crops that produce fruit with diverse flavors and colors.
The fruit ripening behavior of the green ripe mutant ( Gr ) of tomato ( Lycopersicon esculentum Mill.) was examined. Green ripe fruit are climacteric and evolve increasing amounts of ethylene after harvest; however, the time course for these events is dramatically altered in comparison with ‘Rutgers’. Maximal rates of C 2 H 4 evolution from Gr fruit were achieved 20 days after the initial increase, and 7 to 10 days prior to maximal respiratory rates. Fruit age at harvest did not affect either the rate or the magnitude of these processes. Wavelength scans of pigment extracts from 60 day postharvest Gr fruit indicated low levels of carotenoids. Mutant fruit also remain firm a long time after harvest. Polygalacturonase activity in Gr fruit increases with fruit age, but reaches only 3% to 5% of the total activity in ‘Rutgers’. PG activity was only slightly reduced when extracts were heated to 65°C for 5 min, suggesting that a heat stable isoenzyme of PG is predominant in mature mutant fruit in contrast to ‘Rutgers’ in which 90% to 95% of PG activity in ripe fruit is heat labile under these conditions. When heterozygous, the Gr mutation is dominant in its effects on total PG activity and on the time course from the initiation of C 2 H 4 and respiratory increases to their maximal rates of evolution. The magnitude of other changes in heterozygous mutant fruit was intermediate between normal and homozygous Gr .
Transgenic Cantaloupe Charentais melons (Cucumis melo var. cantalupensis Naud. 'Vedrantais') exhibiting strong inhibition of ethylene production were used as a model to discriminate between ethylene-regulated and ethylene-independent ripening pathways. Compared to wild-type fruit, transgenic fruit did not undergo significant yellowing of the rind and softening of the flesh. However, these effects were completely reversed by treating transgenic fruit with 50 μL·L-1 exogenous ethylene. Pigmentation of the flesh occurred early before the onset of the climacteric and was thus unaffected by ethylene inhibition in transgenic fruit. Total soluble solids accumulated at the same rate in both types of fruit until 38 days after pollination when wild-type fruit abscissed. However, as ethylene-inhibited fruit failed to develop a peduncular abscission zone, they remained attached to the plant and accumulated higher amounts of sugars, mainly sucrose. Harvesting transgenic fruit resulted in a small but significant increase of internal ethylene associated with softening of the flesh.
Ripening is a dramatic event in the development of many fleshy fruits. Tomato ripening involves a number of chemical and physical changes which convert the fruit from a relatively inedible state to one of optimal quality (2, 19). These changes appear to be highly synchronized, as evidenced by the fact that respiratory patterns, rate of ethylene production, carotene development, and flavor and textural changes normally associated with the ripening process, occur in close succession during the relatively short period in which the fruit ripens (2, 22). The association of these changes with seed maturation supports the popular view that ripening is of adaptive significance in seed dispersal by rendering fruit attractive to animals responsible for dispersal.
Greenhouse-grown bell pepper (Capsicum annuum L. 'Robusta') were harvested at five stages of maturation (10% red to full red) in early winter 2002 (Expt. 1) and at two stages (10% red and full red) in early Spring 2002 (Expt. 2). The fruit were subsequently stored at 20°C in a continuous-flow chamber consisting of either 100 μL·L-1 ethylene (balance air) or air-only (control) at 90% relative humidity (RH). Individual fruit were removed from the chambers upon reaching full red color, and stored at -30°C until physicochemical analyses were conducted. Harvest maturity, and ethylene exposure had no appreciable effect on pulp soluble solids content, total titratable acidity or pH. Exposure to ethylene hastened ripening time compared to the air control but was independent of fruit maturity at harvest. Fruit exposed to ethylene reached full-red color 6.4 days (Expt. 1) and 4 days (Expt. 2) earlier than air-only fruit, respectively. There were no significant phytochemical and antioxidant differences noted for total carotenoids, total ascorbic acid, and soluble phenolics at various maturity stages due to ethylene exposure. Appreciable differences were observed between the two experiments for phytochemicals and antioxidants, as bell peppers from the latter experiment contained at least twice the concentrations of phytochemicals and antioxidant capacity as those from the first experiment. Differences in these parameters between experiments were attributed to environmental factors such as average temperature, day length, and light intensity. Ethylene was demonstrated to be an effective postharvest treatment for accelerating color change in this bell pepper cultivar, permitting earlier harvest without altering phytochemical synthesis rates.
Ethylene controls fruit ripening. Expression of antisense RNA to the rate-limiting enzyme in the biosynthetic pathway of ethylene, 1-aminocyclopropane-1-carboxylate synthase, inhibits fruit ripening in tomato plants. Administration of exogenous ethylene or propylene reverses the inhibitory effect. This result demonstrates that ethylene is the trigger and not the by-product of ripening and raises the prospect that the life-span of plant tissues can be extended, thereby preventing spoilage.
Alterations in the response of dark-grown seedlings to ethylene (the "triple response") were used to isolate a collection of ethylene-related mutants in Arabidopsis thaliana. Mutants displaying a constitutive response (eto1) were found to produce at least 40 times more ethylene than the wild type. The morphological defects in etiolated eto1-1 seedlings reverted to wild type under conditions in which ethylene biosynthesis or ethylene action were inhibited. Mutants that failed to display the apical hook in the absence of ethylene (his1) exhibited reduced ethylene production. In the presence of exogenous ethylene, hypocotyl and root of etiolated his1-1 seedlings were inhibited in elongation but no apical hook was observed. Mutants that were insensitive to ethylene (ein1 and ein2) produced increased amounts of ethylene, displayed hormone insensitivity in both hypocotyl and root responses, and showed an apical hook. Each of the "triple response" mutants has an effect on the shape of the seedling and on the production of the hormone. These mutants should prove to be useful tools for dissecting the mode of ethylene action in plants.
We have investigated the regulation of gene expression by the plant hormone ethylene by cloning mRNAs that accumulate in unripe tomato fruit (Lycopersicon esculentum) exposed to exogenous ethylene. The response to exogenous ethylene is rapid; within 30-120 min we detect an increase in the cloned mRNA concentrations. DNA sequence analysis indicates that one of the ethylene-inducible genes is related to a gene encoding wound-inducible proteinase inhibitor I. We have measured ethylene production during fruit development and detect low basal levels in unripe fruit and much higher levels in ripening fruit. Blot hybridization experiments show that expression of the cloned genes is developmentally regulated by ethylene during fruit ripening: the mRNAs produced by these genes are more abundant in ripe fruit than in unripe fruit, and this mRNA accumulation is repressed by a competitive inhibitor of ethylene action, norbornadiene. However, during fruit development some of the cloned mRNAs begin to accumulate when ethylene production is at a basal level, whereas other mRNAs begin to accumulate later when the endogenous ethylene concentration increases, suggesting that gene expression during fruit development can be activated by ethylene in two ways. In some cases gene expression is primarily activated by an increase in sensitivity to basal ethylene levels, whereas in other cases it may be regulated by an increase in ethylene concentration.
Ethylene behaves as a hormone in plants, regulating such aspects of growth and development as fruit ripening, flower senescence,
and abscission. Ethylene insensitivity is conferred by dominant mutations in the ETR1 gene early in the ethylene signal transduction
pathway of Arabidopsis thaliana. The ETR1 gene was cloned by the method of chromosome walking. Each of the four known etr1
mutant alleles contains a missense mutation near the amino terminus of the predicted protein. Although the sequence of the
amino-terminal half of the deduced ETR1 protein appears to be novel, the carboxyl-terminal half is similar in sequence to
both components of the prokaryotic family of signal transducers known as the two-component systems. Thus, an early step in
ethylene signal transduction in plants may involve transfer of phosphate as in prokaryotic two-component systems. The dominant
etr1-1 mutant gene conferred ethylene insensitivity to wild-type Arabidopsis plants when introduced by transformation.
A cDNA library produced from mRNA isolated from the pericarp of wild-type tomato fruit (Lycopersicon esculentum Mill. cv Ailsa Craig) at the first visible sign of fruit ripening was differentially screened to identify clones whose homologous mRNAs were present at reduced levels in fruit of the tomato ripening mutant, ripening inhibitor,rin. Five clones were isolated (pERT 1, 10, 13, 14, 15). Accumulation of mRNA homologous to each of these clones increased during the ripening of wild-type fruit and showed reduced accumulation in ripening rin fruit. The levels of three of them (homologous to ERT 1, 13 and 14) were increased by ethylene treatment of the mutant fruit. A further clone, ERT 16 was identified for a mRNA present at a high level in both normal and mutant fruit at early stages of ripening. Database searches revealed no significant homology to the DNA sequence of ERT 14 and 15; however, DNA and derived amino acid sequence of ERT 1 both contain regions of homology with several reported UDP-glucosyl and glucuronosyl transferases (UDPGT) and with a conserved UDPGT motif. A derived amino acid sequence from the ERT 10 cDNA contains a perfect match to a consensus sequence present in a number of dehydrogenases. The ERT 13 DNA sequence has homology with an mRNA present during potato tuberisation. The presence of these mRNAs in tomato fruit is unreported and their role in ripening is unknown. The ERT 16 DNA sequence has homology with a ripening/stress-related cDNA isolated from tomato fruit pericarp.
We isolated a recessive Arabidopsis mutant, ctr1, that constitutively exhibits seedling and adult phenotypes observed in plants treated with the plant hormone ethylene. The ctr1 adult morphology can be phenocopied by treatment of wild-type plants with exogenous ethylene and is due, at least in part, to inhibition of cell elongation. Seedlings and adult ctr1 plants show constitutive expression of ethylene-regulated genes. The epistasis of ctr1 and other ethylene response mutants has defined the position of CTR1 in the ethylene signal transduction pathway. The CTR1 gene has been cloned, and the DNA sequences of four mutant alleles were determined. The gene encodes a putative serine/threonine protein kinase that is most closely related to the Raf protein kinase family.
Dominant mutations in the Arabidopsis ETR1 gene block the ethylene signal transduction pathway. The ETR1 gene has been cloned and sequenced. Using the ETR1 cDNA as a probe, we identified a cDNA homologue (eTAE1) from tomato. eTAE1 contains an open reading frame encoding a polypeptide of 754 amino acid residues. The nucleic acid sequence for the coding sequence in eTAE1 is 74% identical to that for ETR1, and the deduced amino acid sequence is 81% identical and 90% similar. Genomic Southern blot analysis indicates that three or more ETR1 homologues exist in tomato. RNA blots show that eTAE1 mRNA is constitutively expressed in all the tissues examined, and its accumulation in leaf abscission zones was unaffected by ethylene, silver ions (an inhibitor of ethylene action) or auxin.
Ethylene (C2H4) is a gaseous hormone that affects many aspects of plant growth and development. Ethylene perception requires specific receptors and a signal transduction pathway to coordinate downstream responses. The etr1-1 gene of Arabidopsis encodes a mutated receptor that confers dominant ethylene insensitivity. Evidence is presented here that etr1-1 also causes significant delays in fruit ripening, flower sensecence; and flower abscission when expressed in tomato and petunia plants. The ability of etr1-1 to function in heterologous plants suggests that this pathway of hormone recognition and response is highly conserved and can be manipulated.
Mutations in the Arabidopsis ETHYLENE-INSENSITIVE3 (EIN3) gene severely limit a plant's response to the gaseous hormone ethylene. ein3 mutants show a loss of ethylene-mediated effects including gene expression, the triple response, cell growth inhibition, and accelerated senescence. EIN3 acts downstream of the histidine kinase ethylene receptor, ETR1, and the Raf-like kinase, CTR1. The EIN3 gene encodes a novel nuclear-localized protein that shares sequence similarity, structural features, and genetic function with three EIN3-LIKE (EIL) proteins. In addition to EIN3, EIL1 orEIL2 were able to complement ein3, suggesting their participation in the ethylene signaling pathway. Overexpression of EIN3 or EIL1 in wild-type or ethylene-insensitive2 plants conferred constitutive ethylene phenotypes, indicating their sufficiency for activation of the pathway in the absence of ethylene.
The plant hormone ethylene plays a major role in the ripening of climacteric fruit. We have generated transgenic cantaloupe Charentais melons expressing an antisense ACC oxidase gene; ACC oxidase catalyzes the last step of ethylene biosynthesis. Ethylene production of transgenic fruit was < 1% of control untransformed fruit, and the ripening process was blocked both on and off the vine. The antisense phenotype could be reversed by exogenous ethylene treatment. Analysis of antisense ACC oxidase melons indicated that the ripening process includes ethylene-dependent and ethylene-independent pathways. Because the transgenic line we generated displays extended storage life and improved quality, it has a promising potential for commercial development.
We investigated the feedback regulation of ethylene biosynthesis in tomato (Lycopersicon esculentum) fruit with respect to the transition from system 1 to system 2 ethylene production. The abundance of LE-ACS2, LE-ACS4, and NR mRNAs increased in the ripening fruit concomitant with a burst in ethylene production. These increases in mRNAs with ripening were prevented to a large extent by treatment with 1-methylcyclopropene (MCP), an ethylene action inhibitor. Transcripts for the LE-ACS6 gene, which accumulated in preclimacteric fruit but not in untreated ripening fruit, did accumulate in ripening fruit treated with MCP. Treatment of young fruit with propylene prevented the accumulation of transcripts for this gene. LE-ACS1A, LE-ACS3, and TAE1 genes were expressed constitutively in the fruit throughout development and ripening irrespective of whether the fruit was treated with MCP or propylene. The transcripts for LE-ACO1 and LE-ACO4 genes already existed in preclimacteric fruit and increased greatly when ripening commenced. These increases in LE-ACO mRNA with ripening were also prevented by treatment with MCP. The results suggest that in tomato fruit the preclimacteric system 1 ethylene is possibly mediated via constitutively expressed LE-ACS1A and LE-ACS3 and negatively feedback-regulated LE-ACS6 genes with preexisting LE-ACO1 and LE-ACO4 mRNAs. At the onset of the climacteric stage, it shifts to system 2 ethylene, with a large accumulation of LE-ACS2, LE-ACS4, LE-ACO1, and LE-ACO4 mRNAs as a result of a positive feedback regulation. This transition from system 1 to system 2 ethylene production might be related to the accumulated level of NR mRNA.
An allele of the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene (Md-ACS1), the transcript and translated product of which have been identified in ripening apples (Malus domestica), was isolated from a genomic library of the apple cultivar, Golden Delicious. The predicted coding region of this allele (ACS1-2) showed that seven nucleotide substitutions in the corresponding region of ACS1-1 resulted in just one amino acid transition. A 162-bp sequence characterized as a short interspersed repetitive element retrotransposon was inserted in the 5'-flanking region of ACS1-2 corresponding to position -781 in ACS1-1. The XhoI site located near the 3' end of the predicted coding region of ACS1-2 was absent from the reverse transcriptase-polymerase chain reaction product, revealing that exclusive transcription from ACS1-1 occurs during ripening of cv Golden Delicious fruit. DNA gel-blot and polymerase chain reaction analyses of genomic DNAs showed clearly that apple cultivars were either heterozygous for ACS1-1 and ACS1-2 or homozygous for each type. RNA gel-blot analysis of the ACS1-2 homozygous Fuji apple, which produces little ethylene and has a long storage life, demonstrated that the level of transcription from ACS1-2 during the ripening stage was very low.
1-Aminocyclopropane-1-carboxylic acid synthase (ACS) is one of the key regulatory enzymes involved in the synthesis of the hormone ethylene and is encoded by a multigene family containing at least eight members in tomato (Lycopersicon esculentum). Increased ethylene production accompanies ripening in tomato, and this coincides with a change in the regulation of ethylene synthesis from auto-inhibitory to autostimulatory. The signaling pathways that operate to bring about this transition from so-called system-1 to system-2 ethylene production are unknown, and we have begun to address these by investigating the regulation of ACS expression during ripening. Transcripts corresponding to four ACS genes, LEACS1A, LEACS2, LEACS4, and LEACS6, were detected in tomato fruit, and expression analysis using the ripening inhibitor (rin) mutant in combination with ethylene treatments and the Never-ripe (Nr) mutant has demonstrated that each is regulated in a unique way. A proposed model suggests that system-1 ethylene is regulated by the expression of LEACS1A and LEACS6. In fruit a transition period occurs in which the RIN gene plays a pivotal role leading to increased expression of LEACS1A and induction of LEACS4. System-2 ethylene synthesis is subsequently initiated and maintained by ethylene-dependent induction of LEACS2.
The role of ethylene in regulating sugar, acid, texture and volatile components of fruit quality was investigated in transgenic apple fruit modified in their capacity to synthesize endogenous ethylene. Fruit obtained from plants silenced for either ACS (ACC synthase; ACC-1-aminocyclopropane-1-carboxylic acid) or ACO (ACC oxidase), key enzymes responsible for ethylene biosynthesis, expectedly showed reduced autocatalytic ethylene production. Ethylene suppressed fruits were significantly firmer than controls and displayed an increased shelf-life. No significant difference was observed in sugar or acid accumulation suggesting that sugar and acid composition and accumulation is not directly under ethylene control. Interestingly, a significant and dramatic suppression of the synthesis of volatile esters was observed in fruit silenced for ethylene. However, no significant suppression was observed for the aldehyde and alcohol precursors of these esters. Our results indicate that ethylene differentially regulates fruit quality components and the availability of these transgenic apple trees provides a unique resource to define the role of ethylene and other factors that regulate fruit development.
Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants. Here we report that either by syringe-infiltrating the tobacco rattle virus (TRV)-vector into the surface, stem or carpopodium of a tomato fruit attached to the plant or by vacuum-infiltrating into a tomato fruit detached from the plant, TRV can efficiently spread and replicate in the tomato fruit. Although VIGS can be performed in tomato fruit by all of the means mentioned above, the most effective method is to inject the TRV-vector into the carpopodium of young fruit attached to the plant about 10 days after pollination. Several reporter genes related to ethylene responses and fruit ripening, including LeCTR1 and LeEILs genes, were also successfully silenced by this method during fruit development. In addition, we found that the silencing of the LeEIN2 gene results in the suppression of tomato fruit ripening. The results of our study indicate that the application of VIGS techniques by the described methods can be successfully applied to tomato fruit and is a valuable tool for studying functions of the relevant genes during fruit developing.
Nine wild tomato species were surveyed for variability in ripening characteristics. External signs of ripening, age of fruit at ripening, and ethylene production patterns were compared. Ethylene production was monitored using an ethylene-free air stream system and gas chromatography. Based on these ripening characteristics, the fruits fell into three general categories: those that change color when they ripen, green-fruited species that abscise prior to ripening, and green-fruited species that ripen on the vine.The fruits that change color, Lycopersicon esculentum var. cerasiforme, Lycopersicon pimpinellifolium and Lycopersicon cheesmanii, exhibited a peak of ethylene production similar to the cultivated tomato; there were differences, however, in the timing and magnitude of the ethylene production. Peak levels of ethylene production are correlated with age at maturity. For the two species that abscise prior to ripening, Lycopersicon chilense and Lycopersicon peruvianum, ability to produce ethylene varied with stage of maturity. The two species differed from each other in time of endogenous ethylene production relative to abscission, suggesting differences in the control mechanisms regulating their ripening. For two of the green-fruited species that ripen on the vine, Lycopersicon chmielewskii and Lycopersicon parviflorum, ethylene production was correlated to fruit softening. For Lycopersicon hirsutum and Solanum pennellii, however, ethylene production was not correlated with external ripening changes, making questionable the role of ethylene as the ripening hormone in these fruits.
Ethylene influences a number of developmental processes and responses to stress in higher plants. The molecular basis for the action of ethylene was investigated in mutants of Arabidopsis thaliana that have altered responses to ethylene. One mutant line, which has a dominant mutation at a locus designated etr, lacks a number of responses to ethylene that are present in the wild-type plant. These include inhibition of cell elongation, promotion of seed germination, enhancement of peroxidase activity, acceleration of leaf senescence, and feedback suppression of ethylene synthesis by ethylene. These diverse responses, which occur in different tissues of Arabidopsis, appear to share some common element in their transduction pathways—for example, a single receptor for ethylene. Results of ethylene binding experiments in vivo indicate that this receptor may be affected by the etr mutation.
The onset of apple [Malus sylvestris (L.) Mill. Var. domestica (Borkh.)Mansf.] fruit maturity is preceded by the production of ethylene, the ripening hormone, which induces fruit ripening. The amount of ethylene produced by the fruit correlates with the level of transcription of the ripening-specific 1-aminocyclopropane-1-carboxylate (ACC) synthase genes. We have found that an allele (MdACS1-2), which contains an inserted retroposon-like sequence at the 5′-flanking region, is transcribed at a lower level than the wild-type (MdACS1-1). MdACS1-2/2 homozygous fruit produce a lower level of ethylene at the climacteric stage than do the wild type fruit. We have also found that the preharvest drop rates of apple cultivars and strains of MdACS1-2/2 trees have less fruit drop than the MdACS1-1/1 or MdACS1-1/2 trees. Treatment of the MdACS1-1/2 trees with 1-MCP, an ethylene receptor blocker, further decreased fruit drop. Analysis of commercial apple cultivars for the presence of the MdACS1-2/2 allele may help in the early detection of apple cultivars with a low fruit drop rate.
Ethylene production and fruit softening during postharvest storage of several apple ( Malus domestica Borkh.) ripening variants were compared with two standard cultivars. PA14-238 and D101-110 produced only low levels of ethylene (<10 μl·kg –1 ·hour –1 ) at harvest and throughout most of 86 days of storage at 4C, whereas `Red Chief Delicious' and `Golden Delicious' fruit produced >100 μl ethylene/kg per hour during the same time period. PA14-238 and D101-110 flesh disks converted aminocyclopropane-1-carboxylic acid (ACC) but not methionine (MET) to ethylene. `Red Chief Delicious' readily converted both MET and ACC to ethylene at the end of cold storage. PA14-238 fruit were the firmest and did not soften during postharvest storage; however, D101-110 softened appreciably. NJ55 did not produce ethylene at harvest, but produced a significant amount of ethylene (90 μl·kg –1 ·hour –1 ) during storage. Despite its high capacity to produce ethylene, NJ55 remained nearly as firm as PA14-238 at the end of cold storage.
Bell peppers (Capsicum annuum L.) are classified as nonclimacteric fruits while some hot peppers have been reported as climacteric. Responses of peppers to exogenously applied ethylene-releasing compounds suggest ethylene involvement in the ripening process. Ethylene production and respiration rates in 13 cultivars of pepper: 'Camelot', 'Cherry Bomb', 'Chiltepin', 'Cubanelle', 'Banana Supreme', 'Habanero', 'Hungarian Wax', 'Mesilla', 'Mitla', 'Savory', 'Sure Fire', 'Tabasco', and 'King Arthur' were studied under greenhouse and field conditions. Fruit from each cultivar were harvested at different maturity stages determined by color, ranging from mature-green to full red-ripe. Carbon dioxide and ethylene production were measured by gas chromatography. Both variables were significantly different among maturity stages for all cultivars. Respiration rates were between 16.5 and 440.3 mg·kg-1·h-1 CO2. Ethylene production ranged from 0.002 to 1.1 μL·kg-1h-1. Two patterns of CO2 production were identified: higher CO2 production for mature-green fruit with successive decreases for the rest of the maturity stages or lower respiration rates for mature-green fruit with an increase in CO2 production either when fruit were changing color or once fruit were almost totally red. A rise in CO2 production was present for most cultivars. Ethylene evolution increased significantly at maturity or before maturity in all cultivars except 'Cubanelle' and 'Hungarian Wax'. Respiration rates and ethylene production were significantly different among cultivars at the mature-green and red stages.
Tomato plants in which the synthesis of ethylene-forming enzyme (EFE) had been inhibited by an anti-sense gene were used to study the role of ethylene in fruit ripening at the biochemical and molecular level. A reduction in total lycopene accumulation was observed in EFE-antisense fruit ripened both on and off the plant. The rate of over-ripening and fruit spoilage was also reduced in the EFE-antisense fruit. The degree of inhibition of ripening was shown to be dependent upon the stage of development at which the fruit were detached from the plant. The effects on ripening in EFE-antisense fruit were much more pronounced when fruit were detached from the vine before the onset of colour change, and were associated with changes in the level of accumulation of mRNAs homologous to a number of previously characterized ripening-related cDNAs. The retarded ripening of detached EFE-antisense fruit could be partially restored by ethylene treatment. In addition to changes observed in ripening fruit, a temporal delay in the onset of foliar senescence was observed in EFE-antisense plants, indicating that the physiological effects of the EFE-antisense gene, and the associated reduction in ethylene evolution, are not confined specifically to fruit ripening.
Gene expression during the ripening of tomato fruit was investigated by cDNA cloning and hybrid-select translation. A cDNA library was prepared from poly(A)-containing mRNA from ripe tomato fruit and sreened by differential hybridization. 146 ripening-related cDNA clones were found. Eleven groups and eight unique clones have been identified so far. The sizes of the cloned cDNA inserts were determined and type-members for seven groups were used in hybrid selection experiments. Six of the seven clones encode translation products corresponding to six ripening related polypeptides detected previously by in vitro translation of total cytoplasmic RNA (14). One cDNA group codes for a Mr 48 000 protein that was identified as polygalacturonase on the basis of immunoprecipitation with specific antiserum raised against tomato polygalacturonase. re]19840918 rv]19850613 ac]19850618.
Anthocyanin accumulation is one measure of ripening in the strawberry (Fragaria ananassa Duch.), a non-climacteric fruit. Neither aminoethoxyvinylglycine, an inhibitor of 1-aminocyclopropane carboxylic acid synthase, nor inhibitors of ethylene action (silver, norbornadiene) affected anthocyanin accumulation in ripening fruit. When the achenes were removed from one half of an unripe fruit there was an accelerated accumulation of anthocyanin and induction of phenylalanine ammonia lyase on the de-achened portion of the ripening fruit. These effects of achene removal could be prevented by the application of the synthetic auxins 1-naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid to the de-achened surface. The introduction of 1-naphthalene acetic acid into intact unripe strawberry fruit through the peduncle delayed their subsequent ripening, as measured by the accumulation of anthocyanin, loss of chlorophyll and decrease in firmness. These findings suggest that the decline in the concentration of auxin in the achenes as strawberry fruit mature modulates the rate of fruit ripening.
Mature green tomato fruit, infiltrated with STS (up to 10 μmol) while still attached to the plant, ripened unevenly to give extensive green areas on an otherwise red background. Pericarp wall tissue from the two contrasting areas was analysed for various organic constituents. Both the green and, to a certain extent, the red tissue from treated fruit showed differences from normal in AIS, acidity, and PE activity. PG activity, which usually increases rapidly as tomatoes ripen, was low in the green but not significantly different from normal in the red tissue from STS-treated fruit. TEM examination revealed that electron-dense particles were present in the cell walls of phloem elements in vascular bundles of the green tissue, but these deposits were not found in the red tissue from the same fruit. X-ray microanalysis of the particles suggested that they contained concentrations of silver and sulphur. The results are interpreted as suggesting that silver is affecting those sites in the cell that would subsequently be involved in promoting the synthesis of PG.
Application of ethylene to citrus fruit after harvest enhanced external orange and red color by inducing accumulation of specific carotenoid pigments. Cryptoxanthin, β-citraurin, and to a lesser extent, violaxanthin, accumulated in the flavedo of Robinson and other citrus cultivars following treatment with ethylene or 2-chloroethylphosphonic acid (ethephon).
The ethylene antagonists, 2,5-norbornadiene (NBD) and silver nitrate, were used to probe the involvement of endogenous ethylene in the natural degreening of citrus fruit. Mature-green, detached Shamouti orange (Citrus sinensis L. Osbeck) fruit were treated with NBD vapor or dipped in solutions of silver nitrate. More than 80% of the chlorophyll was lost from control fruit after 8 days. NBD (0.11 mmole/liter) inhibited the loss of chlorophyll by 60%. NBD also antagonized the degreening induced by exogenous ethylene by 50%. Silver nitrate (0.1 mM) inhibited the loss of chlorophyll by 55%. Ethylene evolution of mature, green detached fruit was -1.h-1 (ca. 13.5 nl.Kg-1FW.h-1) and did not change significantly for 7 days after harvest. NBD concentrations up to 0.22 mmole/liter did not enhance ethylene evolution. Not with-standing the extremely low amounts of ethylene evolved, the inhibition of degreening by NBD and silver nitrate suggests that endogenous ethylene is involved in the control of this process in mature citrus fruit.
Modification of the plant primary cell wall is required for both cell expansion and for developmental events, such as fruit softening, where cell size remains static but where wall loosening is an important feature. Recent studies suggest that the cellulose–xyloglucan network is targeted by similar enzymatic activities in both expanding cells and ripening fruit but that unique isoforms are expressed in each process. Disassembly of this structural network probably involves the concerted and synergistic action of suites of these enzyme families, where one family of cell wall modifying proteins might mediate the activity of another, providing the basis for orchestrating ordered cell wall restructuring and turnover.
The ripening-impaired tomato mutant Never-ripe (Nr) is insensitive to the plant hormone ethylene. The gene that cosegregates with the Nr locus encodes a protein with homology to the Arabidopsis ethylene receptor ETR1 but is lacking the response regulator domain found in ETR1 and related prokaryotic two-component signal transducers. A single amino acid change in the sensor domain confers ethylene insensitivity when expressed in transgenic tomato plants. Modulation of NR gene expression during fruit ripening controls response to the hormone ethylene.
The key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene is 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.1.1.14). It catalyzes the conversion of S-adenosylmethionine to ACC, the precursor of ethylene. We isolated complementary DNA sequences, ptACC2 and ptACC4, for two distinct and differentially regulated ACC synthase mRNAs expressed in ripe tomato fruit. The authenticity of the clones has been confirmed by expression experiments in E. coli. The predicted size of the encoded polypeptides (54,690 and 53,519 Da) is similar to that of the primary in vitro translation products and to the proteins found in vivo. The sequence of the gene encoding one mRNA, LE-ACC2, has been determined and its transcription initiation site defined. Four additional genes, LE-ACC1A, LE-ACC1B, LE-ACC3 and LE-ACC4, have also been identified and the sequence of their coding regions determined. The LE-ACC1A and LE-ACC1B genes are adjacent to each other and are convergently transcribed. Their encoded polypeptides are 96% identical; the identity of the other polypeptides to each other varies between 50 and 70%. The proteins predicted to be encoded by the ACC synthase genes so far cloned from tomato and zucchini contain 11 of the 12 conserved amino acid residues found in various aminotransferases involved in the binding of the substrate and the cofactor pyridoxal-5'-phosphate. The data indicate that ACC synthase is encoded by a divergent multigene family in tomato that encodes proteins related to aminotransferases.
Synthesis of the phytohormone ethylene is believed to be essential for many plant developmental processes. The control of ripening in climacteric fruits and vegetables is among the best characterized of these processes. One approach to reduce ethylene synthesis in plants is metabolism of its immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). Soil bacteria containing an enzyme, ACC deaminase, were identified by their ability to grow on ACC as a sole nitrogen source. The gene encoding ACC deaminase was cloned and introduced into tomato plants. Reduction in ethylene synthesis in transgenic plants did not cause any apparent vegetative phenotypic abnormalities. However, fruits from these plants exhibited significant delays in ripening, and the mature fruits remained firm for at least 6 weeks longer than the nontransgenic control fruit. These results indicated that ACC deaminase is useful for examining the role of ethylene in many developmental and stress-related processes in plants as well as for extending the shelf life of fruits and vegetables whose ripening is mediated by ethylene.
FLESHY fruits have been divided into two classes on the basis of their
respiratory behaviour during ripening: climacteric fruit, such as
bananas, which undergo a large increase in respiration (climacteric
rise) accompanied by marked changes in composition and texture, and
non-climacteric fruit such as citrus, which show no changes in
respiration that can be associated with distinct changes in the
composition of the fruit1. An increase in the level of
endogenous ethylene is considered to be the immediate trigger of
ripening in climacteric fruits2. Fruits of this class usually
produce large amounts of ethylene once ripening is under way. They may
also be induced to ripen by treatment with ethylene at concentrations
above about 0.1 p.p.m. for a suitable period3. The ripening
induced by exogenous ethylene has been considered to be qualitatively
identical with that which occurs naturally3. In both cases,
once ripening is induced it has been considered that endogenous ethylene
production rises autocatalytically4. Uninjured citrus fruit
have been shown to produce low amounts of ethylene5. Their
respiration may be increased by treatment with ethylene6 and
disappearance of chlorophyll (colouring) and ageing may be more
rapid18.
Twelve cDNAs corresponding to mRNAs inducible by ethylene were isolated by differential screening of a cDNA library from ethylene-treated Citrus sinensis fruits. Northern analysis of RNA extracted from flavedo of ethylene-treated fruits and from fruits at different maturation stages showed that some of the mRNAs corresponding to these cDNAs were regulated both by ethylene treatment and during fruit maturation. The effect of exogenous ethylene on leaves and of endogenous ethylene on flowers showed that gene induction was not restricted to the flavedo tissue. The possible role of ethylene during maturation of the non-climacteric Citrus fruit is discussed.
Fruit ripening represents a complex system of genetic and hormonal regulation of eukaryotic development unique to plants. We are using tomato ripening mutants as tools to elucidate genetic components of ripening regulation and have recently demonstrated that the Never-ripe (Nr) mutant is insensitive to the plant growth regulator ethylene (M.B. Lanahan, H.-C. Yen, J.J. Giovannoni, H.J. Klee [1994] Plant Cell 6:521-530). We report here ethylene sensitivity over a range of concentrations in normal and Nr tomato seedlings and show that the Nr mutant retains residual sensitivity to as little as 1 part per million of ethylene. Analysis of ripening-related gene expression in normal and mutant ethylene-treated fruit demonstrates that Nr exerts its influence on development at least in part at the level of ethylene-inducible gene expression. We have additionally used cloned tomato and Arabidopsis sequences known to influence ethylene perception as restriction fragment length polymorphism probes, and have identified a tomato locus linked to Nr that hybridizes to the Arabidopsis ETR1 gene at low stringency, suggesting the possibility that Nr may be homologous to ETR1.