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Simplified causal loop diagram of functions of plant hormones. B1: Balancing loop between chlorophyll content and fruit development; B2: balancing loop between mineral nutrients and fruit development; B3: balancing loop between chlorophyll and vegetative growth; B4: balancing loop between mineral nutrients and vegetative growth. (+) indicates the change in the variable at the beginning of the arrow produces a change in the same direction in the variable at end on the arrow head, and (-) links two variables with an inverse relationship.
Source publication
The demand for sweet pepper (Capsicum annuum L.) is increasing because of nutrition and quality factors. Research to improve pepper yield using plant growth regulators (PGRs) has occurred, but results are not consistent. This study evaluated the effects of the PGRs naphthalene acetic acid (NAA), gibberellic acid (GA3), 4-chlorophenoxyacetic acid, K...
Contexts in source publication
Context 1
... causal loop diagram was used to illustrate the role of different hormones in the plant system (Figure 1). PGRs applied as treatments were NAA, GA3, ...
Context 2
... applied in this study did not always influence plant physiological responses, but leaf chlorophyll, plant height, and plant biomass were enhanced due to treatment with PGRs. Chlorophyll content may be influenced by leaf area; the initial number of flower and the ability of the plants to limit fruits drop can influence the number of fruits (Figure 1). Information on leaf area, the initial number of flower, and number of fruit on plant just after fruit set could bring more clarity on plant responses to PGRs. ...
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Citations
... Abscisic acid and cytokinin regulate stomatal closure in the presence of CO 2 or water deficit; 52 however, the stimulation of stomatal opening by GA 3 has been shown to increase the accumulation of carbohydrates and potassium in guard cells, which may enhance stomatal conductance in maize plants. 53 Compared with those in the control group, the net stomatal conductance and transpiration rate in the group sprayed with seaweed powder also increased. Significant increases in stomatal conductance and transpiration rate were observed in maize plants treated with various seaweed species, as also reported by Chen et al. ...
Seaweeds carry a wide array of metabolites and nutrients that facilitate growth, development, physiological and biochemical changes in plants, which vary among seaweed species. Among the seaweeds, three distinct seaweed...
... This might be because it influences on chlorophyll content under moderate and severe drought stress levels. Crop yield relies on photosynthesis to make energy for the plants to improve or better yield (Aluko et al., 2021), as in maize (Yan et al., 2021), sweet peppers (Mbandlwa et al., 2020). Also, water deficit is known to stimulate both non-enzymatic and enzymatic antioxidative defense mechanisms during drought stress, which eventually results in altered redox homeostasis (Ullah et al., 2021). ...
Chili peppers (Capsicum annuumL.) are one of the most widely planted vegetables all over the world since it has several health advantages and add a delicious flavor to a range of recipes. Drought stress is accounted as the most abiotic environmental condition that can negatively impact the quality and production of many crops. In this context, a factorial randomized design study was conducted in open field pots to determine how irrigation deficit affects the plant's agronomic and physiological characteristics. Capsicumspp. was subjected to three drought stress conditions (once every day, once every two days, and once every three days representing light or low, moderate, and severe drought stress). At the same time, biostimulants Alga600, moringa leaf extract (MLE), andhomemade fertilizer (H-made) were foliar sprayed to determine whether they might minimize abiotic stress or increase plant susceptibility to drought. The results demonstrate that severe drought stress resulted in a considerable drop in fruit quality and production, followed by moderate and light drought. Whereas, minimum chlorophyll and carotenoids are influenced by deficient irrigation. On the other hand, biostimulants could mitigate the detrimental impact of drought stress on yield, chlorophyll concentration, and other physical characteristics such as leaf area. Among the biostimulants, Alga600 had the greatest impact on increasing chili pepper stress tolerance, followed by 6% MLE and H-made biostimulants when compared to their controls (plants treated with deionized water only). However, the combination of biostimulants with drought stress was more obvious in drought roses. The interaction was less influenced by the drought, which intensified the physical and economic aspects. While some biostimulants, such as MLE and Alga600, may have a greater impact on plant production and pigment content as drought stress increases. The correlation coefficient also indicates that the measured parameters had both positive and negative correlations to each other. Physical parameters like leaf area, number of fruits, fruit diameter, and length have a significant positive correlation to the total yield while chlorophyll content can have a positive and negative correlation to the physical parameters.
... Auxins prevent cellular oxidative processes on pigments and photosynthetic proteins and inactivate catalytic enzymes (Pashang et al. 2021). Gibberellins maintain the integrity of chloroplast membranes in plants subjected to water deficit (Mbandlwa et al. 2019). Cytokinins stimulate the antioxidant defense system and prevent chlorophyll degradation (Raza et al. 2020). ...
Water deficit significantly affects the growth and survival of young plants following transplantation. We performed morphophysiological and biochemical analyses on young yellow passion fruit (Passiflora edulis Sims) plants under well-watered and water-deficit irrigation regimes and pre-treated with three plant growth regulators (PGRs) application—an agrochemical composed of auxins, gibberellins, and cytokinins; salicylic acid (SA); and sodium nitroprusside (SNP), a nitric oxide donor—and a control group with no PGRs. Results showed significant damage by water restriction on biometric attributes; however, the application of PGRs mitigated these effects, reducing growth inhibition processes. In terms of water stress mitigation, differences were observed between PGRs, depending on the morphophysiological or biochemical characteristic. The effectiveness of SNP was higher than the other PGRs in preventing stomatal conductance reduction and maintaining CO2 assimilation, while the agrochemical was the most effective in preventing photosynthetic pigments content decrease. All PGRs promoted osmoregulation in plants subjected to water deficit, thus helping to preserve cell turgor. Furthermore, PGRs application attenuated oxidative stress, either by increasing antioxidant enzymes activity, or by preventing or decreasing the content of thiobarbituric acid-reactive substances, thus preventing lipid peroxidation. These findings suggest that the application of PGRs can be a useful strategy to improve young passion fruit plants tolerance to water restriction following transplantation. The multiple beneficial effects do not allow us to indicate the only one most effective PGR; however, a chemical constituents-related principal component analysis suggests that the agrochemical and SA are the most effective PGRs on mitigating water deficit stress.
... (2015) in the case of Polygonum andZhang et al. (2017) in tomato.Mbandlwa et al. (2019) reported greater dry matter accumulation in sweet pepper plants following the exogenous application of gibberellins and auxin.Li et al. (2008) described the positive role of gibbrellin in the suberization of plant tissues and thereby in increasing dry matter accumulation in plants. Thus, the findings of the present study, which included ...
The present study investigated the effects of several growth regulators on the early growth of banana plants (cv. Grand Naine) at Horticultural Farm, Department of Horticulture and Post-Harvest Technology, Institute of Agriculture, Visva-Bharti, Srinikatan, West Bengal, during 2021-2022. Six different combinations of two growth regulators, viz. GA3 (100, 150 and 200 ppm) and NAA (50 and 100 ppm) were used in combination with a control treatment (no growth regulators) in three replications under a randomized block design. According to the final observation taken at 75 DAP, the maximum plant height (56.33 cm), number of leaves/plant (8.47), and pseudostem diameter (25.72 cm) were observed under T5 (GA3 @ 150 ppm + NAA @ 100 ppm). The greatest sizes with respect to total leaf length (36.71 cm), leaf lamina length (28.06 cm) and breadth were also observed under the same treatment. Thus, the performance of banana plants at an early stage was markedly influenced by the application of different growth regulators, and the combination of GA3 @ 150 ppm and NAA @ 100 ppm was the most effective combination of plant growth regulators for improved growth and development of tissue-cultured banana plants.
... These results are consistent with that conclusion. The fundamental substances increase the production of chlorophyll, which is one of the reasons for the increased levels of photosynthetic activity and chlorophyll seen in this botanical odyssey [36,37,38]. [39]. ...
... PGRs can translocate and partition nutrients from sources to sinks (Jan et al. 2023). Each treatment's biomass may indicate the potential of certain hormones to improve photosynthesis rate and photosynthates translocation effectiveness (Mbandlwa et al. 2019). Gibberellic acid has been focused on many plant species to enhance biomass, yields, and dry matter accumulation (Prajapati et al. 2021;Whitehead and Edwards 2015). ...
... The increased photosynthesis rate conferred by GA 3 treatment might be linked to improved plastid ultra-structural morphogenesis and increased rubisco activity (data not taken). The result is supported by the previous findings that fluctuation in chlorophyll concentration owing to growth regulator treatment is attributable to less chlorophyll degradation and/or enhanced chlorophyll synthesizing (Mbandlwa et al. 2019;Talal and Al-Chalabi 2020). ...
Background
The bitter gourd fruit yields are not at a desirable level due to maleness. Maleness is one of the biggest difficulties with bitter gourd, reducing fruit yields substantially. On the other hand, plant stages are the most important consideration for PGR application because of their sensitive responsiveness. Therefore, it is necessary to determine how bitter gourd plants respond to plant growth regulators, namely PGR 0 (control: application of water as control treatment), PGR 1 (GA 3 -Gibberellic acid, 100 mgL ⁻¹ ), PGR 2 (NAA-Naphthalene acetic acid, 100 mgL ⁻¹ ), and PGR 3 (MH- Maleic hydrazide, 100 mgL ⁻¹ ) at three application phases, S 1 : soaking of seeds; S 2 : four-leaf; and S 3 : flower bud in terms of vegetative development, male–female flower sex alteration, and fruit features including bioactive compounds.
Results
Physiological, floral and yield characteristics of bitter gourd exposed significant changes by GA 3 and MH at various stages. The number of leaves plant ⁻¹ , the fresh mass of the plant, and the fresh mass of fruit and fruit dry matter content were enhanced remarkably for MH application at the seed soaking stage except for plant height and the number of branches plant ⁻¹ . MH increased the number of female flowers plant ⁻¹ , the number of fruits plant ⁻¹ and the yield at the 4-leaf stage of application. PGRs substantially influenced the quantity of sugar, chlorophyll, total carotenoids, protein, and water content at various phases of their application but not on ascorbic acid, TSS, or total phenol concentration.
Conclusions
For sex expression and yield attributes, 100 mgL ⁻¹ MH at the 4-leaf stage would be effective in bitter gourd. Exogenous NAA showed a considerable dual influence on plant development and antioxidant enzyme activity in bitter gourd fruits.
... Sekhar et al. (2018) demonstrated that GA 3 treatment resulted in maximum chlorophyll content, rate of photosynthesis, and stomatal conductance with regard to strawberry (Fragaria × ananassa Duch.). Mbandalwa et al. (2020) observed a positive effect of application of GA 3 and NAA alone and in combination on stomatal conductance and leaf chlorophyll content of hydroponically grown sweet pepper. Islam et al. (2021) reported a positive effect of GA 3 on the contents of chlorophyll and carotenoids of mungbean (Vigna radiata). ...
Coumarins, the naturally occurring benzo-α-pyrone derivatives, are important group of secondary plant metabolites derived from phenylalanine metabolism. Two net house experiment was carried out concurrently to examine the effects of Gibberellic acid (GA3) (Experiment 1) and naphthalene acetic acid (NAA) (Experiment 2) on growth and physiological parameters, and active constituents of Ammi majus, which is a medicinally important plant rich in coumarins and various flavonoids, alkaloids, and terpenoids. Foliar-spray treatments, consisting of increasing concentrations of GA3 (0, 50, 100, 200, and 400 mg/L) and NAA (0, 25, 50, 100, and 200 mg/L) were applied at 45 days after sowing. Application of both of the PGRs improved all of the parameters significantly. The best results were obtained at 100 mg/L of GA3 (Experiment 1) and 50 mg/L of NAA (Experiment 2) in terms of growth characteristics (plant height, fresh weight and dry weight), physiological
parameters (photosynthetic pigments, chlorophyll fluorescence, and activities of nitrate reductase and carbonic anhydrase) and seed-quality parameters (bioactive constituents). The most effective treatments, viz. 100 mg/L of GA3 (Experiment 1) and 50 mg/L of NAA (Experiment 2), resulted in appreciable increases in seed bioactive ingredients. The primary components were Methoxsalen, 7 H-furo [3,2-g] [1] benzopyron-7-one, 4, 9 dimethoxy, and p-camphorene, according to gas liquid chromatographic analyses. In comparison to the control, foliar treatment of GA3 (100 mg/L) considerably increased the plant’s shoot length (29.54%), root length (27.58%), fresh weight (36.78%), and dry weight (41.71%). Whereas, 50 mg/L of NAA enhanced these growth attributes by 31.12%, 32.61%, 34.84%, and 30.32%, respectively, in comparison to the control. Foliar application of 100 mg/L of GA3 increased the chlorophyll fluorescence (51.8%) as well as total content of chlorophyll (39.81%), and carotenoids (47.53%), in contrast with the control. Comparing the control, 50 mg/L of NAA enhanced the chlorophyll fluorescence, and total content of chlorophyll and carotenoids by 42.3%, 30.92%, and 27.81%, respectively. The best foliar-application treatments of 100 mg/L of GA3 and 50 mg/L of NAA were most
effective for NR activity, surpassing the control by 27.7% and 21.5%, respectively. The largest increase in leaf CA activity was observed due to 100 mg/L of GA3 and 50 mg/L of NAA, which exceeded the control by 24.6% and 19.04%, respectively.
... For example, according to Indian scientists (Kar et al., 2016), for the cultivation of sweet pepper, the use of growth regulator NAA (40 mg/l) on the background of potassium fertilizer (120 kg/ha) increases seed yield by 82%. The positive influence of growth regulators on changes in biometric parameters of pepper plants has been confirmed Fotouo et al., 2016;Maboko & Plooy, 2015;Ozlem & Benian, 2007). However, the issue of increasing seed productivity in the seed production of F1 hybrids of sweet pepper with the help of growth regulators has not been studied enough, which, in turn, confirms the relevance of our research. ...
The results of research on the influence of growth regulators: gibberellic acid, succinic acid, and D-2Sl on increasing the seed productivity of sweet pepper F1 hybrids are highlighted. The research was conducted during 2018-2020 at the Institute of Vegetable and Melon NAAS, which is located in the Left Bank Forest-Steppe of Ukraine. The research material was the mother form of the sweet pepper hybrid Zlagoda F1-L. 184/332 in the hybridization nursery. There were used drugs in plants (each in two versions of the rate of consumption): Gibberellic acid (1 mg/l; 5 mg/l), succinic acid (1 mg/l; 5 mg/l), the drug D-2Sl and 2.5 ml/l)-biologically active drug (growth regulator), a derivative of aspartic acid salt and 2-methylpyridine N-oxide, synthesized by the Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine. Treatment with drugs was performed by double spraying in the phase of the beginning of laying the reproductive organs and in the phase of bud formation with a size of 5 mm. Control-treatment of plants with distilled water. It is established that drugs increase seed productivity by 30-50%, depending on the concentration. The highest result was found with the D-2Sl with a rate of 0.5 ml/L and gibberellic acid with a 1 mg/l compared to the control. The use of growth regulators on mother plants during hybridization has a positive effect on the formation of biometric parameters and productivity of the hybrid Zlagoda F1, which can be used as a reserve to increase seed yield and to increase seed yield improve its quality characteristics. Increasing the rate of use of growth regulators leads to a tendency to reduce the seed productivity of plants.
... The results showed that low irradiance and exogenous PP333 could increase the content of Chl, while exogenous GA3 could decrease the content of Chl; low irradiance and exogenous GA3 reduced the Chl a/b ratio, while exogenous PP333 increased the Chl a/b ratio (Fig. 3). The decrease in the Chl content caused by exogenous GA3 may be due to the fact that increases in leaf area caused by GA3 may lead to Chl dilution (Mbandlwa et al. 2020). ...
... e physiological response of plants to gibberellin application is still controversial. Decreases [44] and increases [45] in chlorophyll content have been reported after GA 3 application. Bruinsma et al. [46] have suggested that the increase in leaf area following gibberellin application may cause dilution of chlorophyll and thus a decrease in the content of this parameter compared to the control. ...
The present study was conducted to evaluate the influence of gibberellic acid (25, 50, 100, and 200 ppm) applied on saffron corms previously harvested during different periods (March, June, and before planting) on the growth and the quantitative and qualitative yield of saffron (Crocus sativus L.). The study was carried out in the field during the 2016-2017 and 2017-2018 seasons in the experimental station of the Faculty of Sciences of Oujda (Morocco). The measured parameters correspond, on the one hand, to morphometric measurements and to the determination of the saffron stigma yield and, on the other hand, to the evaluation of the quality of the spice. The results showed that almost all the parameters studied were significantly affected by the factors considered. The treatment of corms just before planting with concentrations of 100 and 200 ppm GA3 showed the highest flower and leaf appearance rate and the highest leaf length and surface area. Moreover, the application of GA3 during the month of March gave the best results in terms of stigmata yield, percentage of large-diameter daughter corms, and the ratio of the number of flowers produced to the total weight of corms. The results of the coefficient of corm propagation revealed that the application of gibberellin during any period improved this coefficient compared to the control. The results indicated that the application of GA3 with concentrations above 25 ppm can improve the growth of saffron and increase its yield under the semiarid climatic conditions of eastern Morocco.
