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Quinoa: Role and Responses Under Abiotic Stress
Abstract
Quinoa (Chenopodium quinoa Willd.) is a hereditarily distinct Andean crop that has received remarkable interest globally owing to its nutritional and health advantages. It is extremely tolerant to harsh environmental conditions, for instance, salt- and water-deficit agroecosystems. Salinity along with drought constitute the major abiotic environmental cues examined in quinoa, whereas additional stressors like heat, frost, heavy metals, waterlogging, and UV-B light are relatively less examined. Moreover, stresses usually act in combinations of two or more. Presently, large gaps exist in our knowledge regarding quinoa’s response to several abiotic stresses, particularly at the molecular level. Even as large genetic variability exists in quinoa species, substantial exploration is necessitated to exploit this genetic diversity. With the recent publication of quinoa reference genome, categorization of genes responsible for abiotic stress tolerance would be intensely facilitated, and a genetic approach should assist in improving our knowledge of varied abiotic stress tolerance mechanisms operative in quinoa, ultimately leading to better propagation approaches. By way of these advances, quinoa has great potential for providing sustainable solutions needed for food safety issues in dry and semi-dry areas worldwide. More or less, not much research has been carried out on quinoa, and relatively lesser has been carried out to explicate the genetics supporting quinoa’s endurance to abiotic factors. With this background, the chapter aims to present (1) a brief overview of quinoa’s history, botanical features, distribution, and economic importance and (2) a recent understanding of the responses and tolerance of quinoa to different abiotic stress factors, focusing on physiological and biochemical responses, possible molecular machinery, and genetic regulation.KeywordsAbiotic stressChenopodiumDroughtHeatQuinoaSalinity
... This characteristic has aroused the interest of researchers and a series of studies have been carried out, in recent years many researchers have shown that quinoa is a plant tolerant to salinity, being recognized for its great natural variability, these characteristics make it an attractive crop for agricultural activity in arid and semiarid zones (Ruiz et al., 2016). In addition, Kaur et al. (2022) mention experiments carried out under salinity conditions ranging from 100 to 750 mM NaCl, where different accessions have been compared, demonstrating that quinoa has a complex trait, associated with mechanisms of tolerance to salinity under multiple processes and conditions (Ruiz et al., 2016). ...
... Likewise, the highest proline content was found in 'Negra Oruro', being significantly different from the other accessions (Table 11). In addition, Table 12 also shows that the highest proline value was found with a salt concentrat ion of 400 mM, being significantly different from the other concentrations; however, at 0 and 200 mM there was nonsignificant difference, this is because metabolites such as proline have a role against salt stress, and this accumulates as salinity increases (Kaur et al., 2022). Table 10. ...
Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte recognized for its genetic variability and high tolerance to salinity. The objective of this study was to evaluate the effect of NaCl on three accessions of quinoa from the Camacani germplasm bank of the National University of the Altiplano, Perú, at three NaCl concentrations (0, 200 and 400 mM) under greenhouse conditions. Four morphological variables (plant height, root length, percentage of root DM, and aerial DM), as well as seven metabolic variables (chlorophyll, proline, phenols, flavonoids, saponins, amino acids and proteins content by spectrophotometric analysis) and electrolyte leakage (EL) in leaves were analyzed. Increasing NaCl exposure was positively correlated with increases in EL, proline, and saponin, while negatively correlated with leaf protein content. In accession PECQ 20037, for example, foliar protein content varied from 18.7% at 0 mM NaCl to 10.57% at 400 mM NaCl. The results indicated that accessions PECQ 20037 and Negra Oruro tolerated the 400 mM NaCl concentration better than Sajama.
... The significant role of ABA in plant-water balance and development is well-established [36]. Under drought stress, quinoa plants (variety 'INIA-Illpa') had elevated levels of ABA in their roots, as reported by Kaur et al. [37]. In addition, leaves of the 'Titicaca' sea-level variety had high ABA levels when grown under both water-deficient and controlled conditions [38]. ...
Quinoa (Chenopodium quinoa Willd.) has gained worldwide recognition for its nutritional values, adaptability to diverse environments, and genetic diversity. This review explores the current understanding of quinoa tolerance to environmental stress, focusing on drought, salinity, heat, heavy metals, and UV-B radiation. Although drought and salinity have been extensively studied, other stress factors remain underexplored. The ever-increasing incidence of abiotic stress, exacerbated by unpredictable weather patterns and climate change, underscores the importance of understanding quinoa’s responses to these challenges. Global gene banks safeguard quinoa’s genetic diversity, supporting breeding efforts to develop stress-tolerant varieties. Recent advances in genomics and molecular tools offer promising opportunities to improve stress tolerance and increase the yield potential of quinoa. Transcriptomic studies have shed light on the responses of quinoa to drought and salinity, yet further studies are needed to elucidate its resilience to other abiotic stresses. Quinoa’s ability to thrive on poor soils and limited water resources makes it a sustainable option for land restoration and food security enterprises. In conclusion, quinoa is a versatile and robust crop with the potential to address food security challenges under environmental constraints.
Genotype × environment (GxE) interaction effects are one of the major challenges in identifying cultivars with stable performance across agri-environments. In this study we analysed GE interactions to identify quinoa (Chenopodium quinoa) cultivars with high and stable yields under different soil moisture regimes, representing control conditions, waterlogging and drought. Waterlogging and drought treatments were artificially induced using normoxia, a combination of hypoxia-normoxia, and 10% PEG (Polyethylene glycol) under hydroponic growth conditions, respectively. Both waterlogging and drought conditions significantly reduced the plant height (PH), number of leaves (NoL) and number of branches (NoB), stem diameter (SD), leaf area (LA) and dry weight (DW) of quinoa genotypes. The genotype, water regime, and genotype by water regime effects all significantly affected the measured quinoa traits. Based on the additive main effects and multiplicative interaction (AMMI) model for DW, the genotypes G18, Puno, Q4, 2-Want, Puno, Real1 x Ruy937 and Titicaca were found to exhibit tolerance and were stable across water regimes. A second-stage evaluation was conducted to test genotype × environment interaction effects in crop production field trials, selecting two contrasting seasons based on soil moisture conditions involving a diverse set of genotypes (58 varieties in total). Our results demonstrate significant variations in both growth and yield among the quinoa genotypes across the cropping seasons. The GGE analysis for grain yield indicate that field conditions matched to G × E under hydroponic experimental conditions and the cultivars G18, Q1, Q4, NL-3, G28, 42-Test, Atlas and 59-ALC were classified within a range of high productivity. Our findings provide a basis for understanding the mechanisms of wide adaptation, while identifying germplasm that enhances the water stress tolerance of quinoa cultivars at early growth stages.
Quinoa is an important crop for food security and food sovereignty in Ecuador. In this study, we evaluated the nutritional value, bioactive compounds, and antinutrient compounds of leaves and grains of the Ecuadorian quinoa variety Tunkahuan, and we identified significant differences between the nutrient content in the leaves and grains. The quinoa leaves presented a higher protein content than the grains, as well as inorganic nutrients such as calcium, phosphorus, iron, and zinc. Both the grains and leaves had an appreciable phenolic content. In addition, the quinoa grains presented a higher content of the antinutrient saponin than the leaves, while the leaves contained more nitrates and oxalates than the grains. Thus, quinoa leaves and grains exhibit excellent potential for application in the food and pharmaceutical industries.
Review Article Many herbs in traditional and modern medicine comprise saponins, which are generally responsible for the therapeutic properties they possess. Many saponins are known to show biological activities such as antiviral, antidiabetic, and cytotoxic properties. These substances and plants containing them are becoming more and more attractive for pharmacological research purposes. Quinoa seed, which contains various phytochemicals and antioxidant substances, is one of the grain groups on which research has been conducted and the mechanisms of its effects are intended for clarification. This study aims to explain the effects of its consumption on health by giving information about the chemical composition of quinoa seeds and by showing scientific data as an example. The results obtained in the literature studies have determined that quinoa has an important potential to be used as a food supplement, in pharmacology, and in the production of new food products, thanks to the positive effects of its consumption on health.
Quinoa (Chenopodium quinoa Will.) is an annual herbaceous Andean plant. In recent years there is a growing interest on it due to its high quality as food, its wide adaptation to agroecological conditions and resistance to different abiotic stresses. In this work, we evaluate the growth pattern of quinoa plants cv. ‘Titicaca’, subjected to different levels of salinity, focusing on leaf production and nutrient content. In this sense, the results have shown that a high concentration of salinity negatively affects the growth of quinoa plants. In fact, plants grown with 200 mM NaCl reduced the photosynthetic rate and levels of chlorophylls and carotenoids in comparison with the rest of the treatments. Likewise, it has been proven how the progressive increase in salinity has negative effects on transpiration, stomatal conductance and photosynthetic rate, with significant subsequent reductions in shoot biomass, leaf area and nutrient adquisition, but without a decline in leaf dry weight (DW) production. However, the treatment of 200 mM NaCl demonstrated the best results regarding the water-use efficiency, as well as the number of saline glands. According to our results, the quinoa plant cv. ‘Titicaca’ seems to be tolerant to moderate concentrations of salinity (50–100 mM NaCl). This study could serve as a reference on this little known and cultivated species in the Mediterranean region, since it could become an alternative crop in areas with moderate salinity problems.
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
Citation: González, J.A.; Hinojosa, L.; Mercado, M.I.; Fernández-Turiel, J.L.; Bazile, D.; Ponessa, G.I.; Eisa, S.; González, D.A.; Rejas, M.; Hussin, S.; et al. A Long Journey of CICA-17
Quinoa may be a promising alternative solution for arid regions, and it is necessary to test yield and mineral accumulation in grains under different soil types. Field experiments with Chenopodium quinoa (cv. CICA-17) were performed in Egypt in non-saline (electrical conductivity, 1.9 dS m-1) and saline (20 dS m-1) soils. Thirty-four chemical elements were studied in these crops. Results show different yields and mineral accumulations in the grains. Potassium (K), P, Mg, Ca, Na, Mn, and Fe are the main elements occurring in the quinoa grains, but their concentrations change between both soil types. Besides, soil salinity induced changes in the mineral pattern distribution among the different grain organs. Sodium was detected in the pericarp but not in other tissues. Pericarp structure may be a shield to prevent sodium entry to the underlying tissues but not for chloride, increasing its content in saline conditions. Under saline conditions, yield decreased to near 47%, and grain sizes greater than 1.68 mm were unfavored. Quinoa may serve as a complementary crop in the marginal lands of Egypt. It has an excellent nutrition perspective due to its mineral content and has a high potential to adapt to semi-arid and arid environments.
Background
Soil salinity is one of the major abiotic stress factors that affect crop growth and yield, which seriously restricts the sustainable development of agriculture. Quinoa is considered as one of the most promising crops in the future for its high nutrition value and strong adaptability to extreme weather and soil conditions. However, the molecular mechanisms underlying the adaptive response to salinity stress of quinoa remain poorly understood. To identify candidate genes related to salt tolerance, we performed reference-guided assembly and compared the gene expression in roots treated with 300 mM NaCl for 0, 0.5, 2, and 24 h of two contrasting quinoa genotypes differing in salt tolerance.
Results
The salt-tolerant (ST) genotype displayed higher seed germination rate and plant survival rate, and stronger seedling growth potential as well than the salt-sensitive (SS) genotype under salt stress. An average of 38,510,203 high-quality clean reads were generated. Significant Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified to deeper understand the differential response. Transcriptome analysis indicated that salt-responsive genes in quinoa were mainly related to biosynthesis of secondary metabolites, alpha-Linolenic acid metabolism, plant hormone signal transduction, and metabolic pathways. Moreover, several pathways were significantly enriched amongst the differentially expressed genes (DEGs) in ST genotypes, such as phenylpropanoid biosynthesis, plant-pathogen interaction, isoquinoline alkaloid biosynthesis, and tyrosine metabolism. One hundred seventeen DEGs were common to various stages of both genotypes, identified as core salt-responsive genes, including some transcription factor members, like MYB, WRKY and NAC, and some plant hormone signal transduction related genes, like PYL, PP2C and TIFY10A, which play an important role in the adaptation to salt conditions of this species. The expression patterns of 21 DEGs were detected by quantitative real-time PCR (qRT-PCR) and confirmed the reliability of the RNA-Seq results.
Conclusions
We identified candidate genes involved in salt tolerance in quinoa, as well as some DEGs exclusively expressed in ST genotype. The DEGs common to both genotypes under salt stress may be the key genes for quinoa to adapt to salinity environment. These candidate genes regulate salt tolerance primarily by participating in reactive oxygen species (ROS) scavenging system, protein kinases biosynthesis, plant hormone signal transduction and other important biological processes. These findings provide theoretical basis for further understanding the regulation mechanism underlying salt tolerance network of quinoa, as well establish foundation for improving its tolerance to salinity in future breeding programs.
Cultivation of quinoa (Chenopodium quinoa), an annual pseudocereal crop that originated in the Andes, is spreading globally. Because quinoa is highly nutritious and resistant to multiple abiotic stresses, it is emerging as a valuable crop to provide food and nutrition security worldwide. However, molecular analyses have been hindered by the genetic heterogeneity resulting from partial outcrossing. In this study, we generated 136 inbred quinoa lines as a basis for the molecular identification and characterization of gene functions in quinoa through genotyping and phenotyping. Following genotyping-by-sequencing analysis of the inbred lines, we selected 5,753 single-nucleotide polymorphisms (SNPs) in the quinoa genome. Based on these SNPs, we show that our quinoa inbred lines fall into three genetic sub-populations. Moreover, we measured phenotypes, such as salt tolerance and key growth traits in the inbred quinoa lines and generated a heatmap that provides a succinct overview of the genotype-phenotype relationship between inbred quinoa lines. We also demonstrate that, in contrast to northern highland lines, most lowland and southern highland lines can germinate even under high salinity conditions. These findings provide a basis for the molecular elucidation and genetic improvement of quinoa and improve our understanding of the evolutionary process underlying quinoa domestication.
The effects of climate change and soil salinization on dryland ecosystems are already widespread, and ensuring food security is a crucial challenge. In this article, we demonstrate changes in growth performance and seed quality of a new high-yielding quinoa genotype (Q5) exposed to sodium chloride (NaCl), sodium sulfate (Na2SO4), and mixed salts (NaCl + Na2SO4). Differential responses to salt stress in growth performance, seed yield, and seed quality were identified. High salinity (mixed Na2SO4 + NaCl) reduces plant height by ∼30%, shoot and root dry weights by ∼29%, head panicle length and panicle weight by 36–43%, and seed yield by 37%, compared with control conditions. However, the 1,000-seed weight changes insignificantly under salinity. High content of essential minerals, such as Fe, Zn, and Ca in quinoa Q5 seeds produced under salinity, gives the Q5 genotype a remarkable advantage for human consumption. Biomarkers detected in our studies show that the content of most essential amino acids is unchanged under salinity. The content of amino acids Pro, Gly, and Ile positively correlates with Na⁺ concentration in soil and seeds, whereas the content of squalene and most fatty acids negatively correlates. Variation in squalene content under increasing salinity is most likely due to toxic effects of sodium and chlorine ions as a result of the decrease in membrane permeability for ion movement as a protective reaction to an increase in the sodium ion concentration. Low squalene accumulation might also occur to redirect the NADPH cofactor to enhance the biosynthesis of proline in response to salinity, as both syntheses (squalene and proline) require NADPH. This evidence can potentially be used by the food and pharmaceutical industries in the development of new food and health products.
Escalating salinization due to natural and anthropogenic activities is a major threat to sustainability of agriculture over the world. In this situation quinoa can be a good option for salt-affected soils. It is a facultative halophyte which can tolerate salinity levels up to the level of sea water. Due to these characters, interest to grow this crop has increased exponentially in recent years over the globe, and many studies have been conducted to elucidate salt-tolerance mechanisms and to explore growth performance and seed quality under various salt regimes. It seems that quinoa manages excessive Na+ loads efficiently by sequestering it in leaf vacuoles and translocating it to older leaves; it has a good antioxidative defense system, better K+ uptake and retention, and unique modulations in stomatal density and characters. Furthermore, it has been observed that its growth and yield improves at moderate salt regimes, even with higher amounts of protein and some minerals. These characteristics offer opportunities that quinoa can be explored in arid and semiarid regions where crop production of various major crops is severely affected by escalated soil salinization.
Halophytes are plants that grow in high-salt environments and form characteristic epidermal bladder cells (EBCs) that are important for saline tolerance. To date, however, little has been revealed about the formation of these structures. To determine the genetic basis for their formation, we applied ethylmethanesulfonate mutagenesis and obtained two mutants with reduced levels of EBCs (rebc) and abnormal chloroplasts. In silico subtraction experiments revealed that the rebc phenotype was caused by mutation of REBC, which encodes a WD40 protein that localizes to the nucleus and chloroplasts. Phylogenetic and transformant analyses revealed that the REBC protein differs from TTG1, a WD40 protein involved in trichome formation. Furthermore, rebc mutants displayed damage to their shoot apices under abiotic stress, suggesting that EBCs may protect the shoot apex from such stress. These findings will help clarify the mechanisms underlying EBC formation and function.
The effect of heat stress on quinoa (cv. Titicaca) under controlled climatic conditions. Abstract Quinoa (Chenopodium quinoa Willd.) is capable of adapting to multiple environments and tolerating abiotic stresses including saline, drought and frost stress conditions. However, the introduction of quinoa into new environments has disclosed adaptation challenges. The principle factor affecting crop pollination is heat stress at flowering, which leads to sterile plants. To investigate the effect of high temperatures during the sensitive phenological phases, flowering and seed germination, a Danish-bred cultivar (cv. Titicaca) was grown in climatic chambers. Selection of the cv. Titicaca was based on the fact that it is the most extensively used cultivar in the Sahel and Middle East and North African region. The results of this research demonstrated that temperatures exceeding 38°C hindered seed germination and pollination, and therefore, seed yield at harvest. At 38°C, seed yield losses were 30%, whilst seed germination percentage declined below 50%. In addition, the results of the present research were compared with field observations from Burkina Faso in order to determine the spatiotemporal suitability of this crop with respect to temperature stress.
Quinoa is an important staple food crop for millions of impoverished rural inhabitants of the Andean region. Quinoa is considered a good source of protein,vitamins, minerals, and antioxidants. This study aimed to investigate the genetic diversity and population structure of world quinoa germplasm originating from 8 countries through the iPBS-retrotransposon marker system. Molecular characterization was performed using the 11 most polymorphic primers. A total of 235 bands were recorded, of which 66.8% were polymorphic. Mean polymorphism information content (PIC) was 0.410. Various diversity indices including mean effective number of alleles (1.269), mean Shannon’s information index (0.160) and gene diversity (0.247) revealed the existence of sufficient amount of genetic diversity in studied germplasm. Bolivia–17 and Mexico–1 were found to be genetically distinct accessions and can be suggested as candidate parents for future breeding activities. Various diversity indices were also calculated among germplasm collection counries and the results clearly showed the existence of higher genetic diversity in Bolivian and Peruvian accessions. The model-based structure, neighbor-joining, and principal coordinate analysis (PCoA) grouped quinoa germplasm according to their collection country. Analysis of molecular variance (AMOVA) revealed that most of the variations (69%) in world quinoa germplasm are due to differences within populations. Findings of this study can be used for deeper understanding of the genetic relationship and in the determination of appropriate breeding and conservation strategies for quinoa.
Several food-derived molecules, including proteins and peptides, can show bioactivities toward the promotion of well-being and disease prevention in humans. There is still a lack of information about the potential effects on immune and inflammatory responses in mammalian cells following the ingestion of seed storage proteins. This study, for the first time, describes the potential immunomodulation capacity of chenopodin, the major protein component of quinoa seeds. After characterizing the molecular features of the purified protein, we were able to separate two different forms of chenopodin, indicated as LcC (Low charge Chenopodin, 30% of total chenopodin) and HcC (High charge Chenopodin, 70% of total chenopodin). The biological effects of LcC and HcC were investigated by measuring NF-κB activation and IL-8 expression studies in undifferentiated Caco-2 cells. Inflammation was elicited using IL-1β. The results indicate that LcC and HcC show potential anti-inflammatory activities in an intestinal cell model, and that the proteins can act differently, depending on their structural features. Furthermore, the molecular mechanisms of action and the structural/functional relationships of the protein at the basis of the observed bioactivity were investigated using in silico analyses and structural predictions.
The increase in temperature and constant changes in climate negatively affects the
development of the plants, which has resulted in an alarming situation for many of
the different crops of agricultural and food interest. In the specific case of quinoa,
the investigation points to a significant loss in the productivity of the grain crop
indicating differences depending on the altitudes of the areas of agriculture
production and the availability of water. A current informed description of the
responses regarding phonological development under stressful conditions could
help us develop appropriate strategies to improve the conditions for the production
of quinoa and allow us to propose cultivation of the product under environmental
conditions where other products cannot survive. The main discoveries regarding
this study were framed within the effect of caloric stress on the germination of
quinoa seeds, their phenology, their response to different evaluated cultivars and
their effects on their growth as well as their physiological and productive levels.
Thus, the analysis is described based on a review of the available scientific
documents available in the Scopus database and doctoral work thesis, allowing for
the consolidation of the most recent investigations regarding the quinoa and their
relationship with temperature.
En este estudio se analiza la variabilidad climática de dos regiones de importancia agropecuaria en los departamentos de Boyacá y Cundinamarca (Colombia). Se identifican comportamientos modales de variables climáticas de interés agropecuario, así mismo, se realiza el análisis intra-anual de eventos extremos y se identifican áreas con deficiencias y excesos hídricos a través de un balance hidroclimático. Además, se identifican zonas con mayor frecuencia de condiciones de deficiencias y excesos hídricos en el suelo a escala mensual por medio del Índice de Severidad de Sequía de Palmer (PSDI). Los resultados indican que ambas zonas de estudio no muestran grandes diferencias climáticas entre sí, sin embargo, es importante realizar el estudio por separado con la intención de proporcionar información local de utilidad para los productores. Saboyá en el Valle de Ubaté y Chiquinquirá y Sotaquirá en el Alto Chicamocha son altamente afectados por eventos tanto de deficiencia como exceso hídrico. El evento El Niño 1997 tuvo un impacto más fuerte en el área del Valle de Ubaté y Chiquinquirá, mientras que en el Alto Chicamocha se registró la mayor reducción de la precipitación en 1992, lo que coincidió con un evento El Niño. En cuanto a excesos hídricos, 2011 registró aumentos superiores a 50% en la precipitación en las regiones del estudio, este comportamiento responde al evento La Niña registrado ese año.
Quinoa (Chenopodium quinoa Willd.) is native to the Andean region and has attracted a global growing interest due its unique nutritional value. The protein content of quinoa grains is higher than other cereals while it has better distribution of essential amino acids. It can be used as an alternative to milk proteins. Additionally, quinoa contains a high amount of essential fatty acids, minerals, vitamins, dietary fibers, and carbohydrates with beneficial hypoglycemic effects while being gluten-free. Furthermore, the quinoa plant is resistant to cold, salt, and drought, which leaves no doubt as to why it has been called the "golden grain". On that account, production of quinoa and its products followed an increasing trend that gained attraction in 2013, as it was proclaimed to be the international year of quinoa. In this respect, this review provides an overview of the published results regarding the nutritional and biological properties of quinoa that have been cultivated in different parts of the world during the last two decades. This review sheds light on how traditional quinoa processing and products evolved and are being adopted into novel food processing and modern food products, as well as noting the potential of side stream processing of quinoa by-products in various industrial sectors. Furthermore, this review moves beyond the technological aspects of quinoa production by addressing the socioeconomic and environmental challenges of its production, consumption, and marketizations to reflect a holistic view of promoting the production and consumption of quinoa.
Abstract Background Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypes in response to salt. To investigate the salinity tolerance mechanisms, five contrasting quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling’s responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl). Results Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the different quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (
If two related plant species hybridise, their genomes may be combined and duplicated within a single nucleus, thereby forming an allotetraploid. How the emerging plant balances two co‐evolved genomes is still a matter of ongoing research. Here, we focus on satellite DNA (satDNA), the fastest turn‐over sequence class in eukaryotes, aiming to trace its emergence, amplification and loss during plant speciation and allopolyploidisation. As a model, we used Chenopodium quinoa Willd. (quinoa), an allopolyploid crop with 2n=4x=36 chromosomes. Quinoa originated by hybridisation of an unknown female American Chenopodium diploid (AA genome) with an unknown male Old World diploid species (BB genome), dating back 3.3 to 6.3 million years. Applying short read clustering to quinoa (AABB), C. pallidicaule (AA), and C. suecicum (BB) whole genome shotgun sequences, we classified their repetitive fractions, and identified and characterised seven satDNA families, together with the 5S rDNA model repeat. We show unequal satDNA amplification (two families) and exclusive occurrence (four families) in the AA and BB diploids by read mapping as well as Southern, genomic and fluorescent in situ hybridisation. As C. pallidicaule harbours a unique satDNA profile, we are able to exclude it as quinoa’s parental species. Using quinoa long reads and scaffolds, we detected only limited evidence of intergenomic homogenisation of satDNA after allopolyploidisation, but were able to exclude dispersal of 5S rRNA genes between subgenomes. Our results exemplify the complex route of tandem repeat evolution through Chenopodium speciation and allopolyploidisation, and may provide sequence targets for the identification of quinoa’s progenitors.
Nitrogen economy is a subject that is growing in popularity at the global level, especially in relation to the agricultural activity, due to nutrient leaching caused by fertilization, as it contributes to the eutrophication of water. As a result, the population of algae increases, and thus, oxygen availability is reduced by accelerating the denitrification process in which N2O is produced, known mostly for its effect on global warming. Likewise, part of the fertilizer is emitted into the atmosphere by volati-lization. This has led to the creation of techniques that allow quantifying the nitrogen used by plants and the one that is fixated in the soil through micro-organisms to make more efficient the use of nitrogen in agricultural systems. However, the most significant limitations are their sensitivity, specificity, cost, and the technolog y that is required to apply them. This has also led to the innovation of procedures and the creation of techniques that have a very low error rate. The aim of this work was to describe the main techniques used to quantify nitrogen fixation with emphasis on the back-ground, procedures, mathematical expressions that are used and future scenarios. The information is described from the analysis of available trials included in the Scopus database. This work consolidates the techniques that continue to be used to quantify nitrogen and facilitates their use over time with prediction models, as well as their importance, advantages, and disadvantages.
Quinoa (Chenopodium quinoa Willd.) is a grain crop grown in the Andes renowned as a highly nutritious plant exhibiting tolerance to abiotic stress such as drought, cold and high salinity. Quinoa grows across a range of latitudes corresponding to differing day lengths, suggesting regional adaptations of flowering regulation. Improved understanding and subsequent modification of the flowering process, including flowering time, ensuring high yields, is one of the key factors behind expansion of cultivation zones and goals of the crop improvement programs worldwide. However, our understanding of the molecular basis of flower initiation and development in quinoa is limited. Here, we use a computational approach to perform genome-wide identification and analysis of 611 orthologues of the Arabidopsis thaliana flowering genes. Conservation of the genes belonging to the photoperiod, gibberellin and autonomous pathways was observed, while orthologues of the key genes found in the vernalisation pathway (FRI, FLC) were absent from the quinoa genome. Our analysis indicated that on average each Arabidopsis flowering gene has two orthologous copies in quinoa. Several genes including orthologues of MIF1, FT and TSF were identified as homologue-rich genes in quinoa. We also identified 459 quinoa-specific genes uniquely expressed in the flower and/or meristem, with no known orthologues in other species. The genes identified provide a resource and framework for further studies of flowering in quinoa and related species. It will serve as valuable resource for plant biologists, crop physiologists and breeders to facilitate further research and establishment of modern breeding programs for quinoa.
Abstract Background Magnolia wufengensis is a new species of Magnolia L. and has considerable ornamental and economic value due to its unique characteristics. However, because of its characteristic of poor low temperature resistance, M. wufengensis is hardly popularization and application in the north of China. Furthermore, the mechanisms of gene regulation and signaling pathways involved in the cold-stress response remained unclear in this species. In order to solve the above-mentioned problems, we performed de novo transcriptome assembly and compared the gene expression under the natural (25 °C) and cold (4 °C) conditions for M. wufengensis seedlings. Results More than 46 million high-quality clean reads were produced from six samples (RNA was extracted from the leaves) and were used for performing de novo transcriptome assembly. A total of 59,764 non-redundant unigenes with an average length of 899 bp (N50 = 1,110) were generated. Among these unigenes, 31,038 unigenes exhibited significant sequence similarity to known genes, as determined by BLASTx searches (E-value ≤1.0E-05) against the Nr, SwissProt, String, GO, KEGG, and Cluster of COG databases. Based on a comparative transcriptome analysis, 3,910 unigenes were significantly differentially expressed (false discovery rate [FDR]
Five experiments were conducted to investigate the nutritional value of various legumes and a faba beans processing co-product for broilers. In Expt. 1 and 3, metabolizable energy (AME) content was evaluated for 2 batches of bean starch concentrate (BSC) that differed in physical and chemical characteristics. Standardized ileal amino acid digestibility (SIAAD) was determined for BSC in Expt. 2, and for corn, soybean meal (SBM), organic and conventional faba beans, and quinoa (Expt. 4). The growth performance response of broiler chickens to partial replacement of wheat and SBM with various legumes was investigated in Expt. 5. The AME of the BSC assayed in Expt. 1 was lower (P < 0.01) than that of the BSC assayed in Expt. 3. The SIAAD was generally high for BSC in Expt. 2 although the content and digestibility of sulfur amino acids were low. In Expt. 4, there was no difference in SIAAD of Arg, Phe, Asp, and Gly among the different feedstuffs assayed. SIAAD was largely similar for both conventional and organic faba bean. The SIAADs of Met, Thr, Ser, and Tyr were lower (P < 0.05) for quinoa compared with SBM or corn. In Expt. 5, FCR was greater (P < 0.05) for broiler chickens receiving faba beans+barley mix or lupins compared with the wheat-SBM control diet. Amino acid digestibility was greater (P < 0.01) for the diets containing lupins compared with the other diets except for Lys, Met, Thr, Ala, Asp, and Ser. On the other hand, amino acid digestibility in diet with faba beans+barley mix was lower (P < 0.05) compared with all the other diets, except for Arg, Asp, Lys, and Thr. It was concluded from the current studies that there is scope for using the assayed legumes, co-products, and quinoa in broiler chickens to partly replace SBM as protein feedstuffs.
Environmental stresses, such as temperature, heavy metals, drought, cold, and microbial infections adversely damage various aspects of plant growth and development. Salinity and drought are among major hazardous factors, which adversity affects plant growth and productivity. Transcription factors, such as basic helix-loop-helix play critical roles in regulating plant physiological processes under abiotic stresses. In this study, we presented the characterization of a tomato SlbHLH22 gene under abiotic stresses such as drought and salinity. Plants overexpressing SlbHLH22 showed short height with small leaves and enhanced flavonoid accumulation. In wild type (WT) plant, the elevated levels of SlbHLH22 were detected under salt and D-mannitol stresses. Subcellular localization analysis revealed that SlbHLH22 protein was targeted to the nucleus in onion epidermal cells. Transactivation assay in yeast demonstrated that SlbHLH22 had transcriptional activation ability. The transgenic plants overexpressing SlbHLH22 displayed enhanced vigor and more tolerant to drought and salinity than WT. Overexpression of SlbHLH22 significantly peaked the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) to minimize the impacts of reactive oxygen species such as H2O2, which was reduced significantly in transgenic plants along with Malondialdehyde (MDA). Moreover, the expression levels of ROS defense genes (SlPOD, SlCAT, SlSOD), ABA biosynthesis genes, proline biosynthesis, and flavonoids synthesis genes were also activated under salinity and drought. Taken together, our study implies that the overexpression of SlbHLH22 improved tomato plant stress resistance by improving ROS scavenging system, increasing osmotic potential and enhanced accumulation of secondary metabolites in tomato plants.
The objective of this study was to investigate the drought-related adaptation strategies of two quinoa (Chenopodium quinoa Willd.) cultivars grown under controlled conditions. After 34 days of growth, water was withheld until plants were severely wilted, then they were re-watered and left to recover. 20 days later the experiment was reproduced. We analyzed growth, biomass, stomatal density, leaf water status, chlorophyll and malonyldialdehyde (MDA) content. Results showed that under water stress growth, biomass, stomatal density and leaf water status were significantly affected. On the other hand, results showed that water stress in the initial period can significantly increase the tolerance to drought during later phases. The data showed that quinoa drought tolerance may result from its capacity to maintain cell health status. Our findings provide new tracks into the mechanisms of drought tolerance in quinoa plants.
This chapter presents a summary of the existing literature on the history, types, nutritional composition, phytonutrients/bioactives, antinutrients, and health effects of quinoa seed. Traditionally, quinoa seeds, on the basis of their color, are classified as red, black, and white or ivory. Nutritional composition of the quinoa grain varies with variety, climate, and other environmental factors. Phytonutrients and/or antinutrients are secondary metabolites categorized as having both beneficial and adverse health effects, depending upon the concentration in the dietary intake. The presence of bioactives, essential amino acids, higher amounts of vitamins and minerals, Ω‐3 fatty acids and the absence of gluten make quinoa suitable not only for those who cannot tolerate gluten, but also for the general population who are at risk of various chronic diseases. A number of studies have demonstrated that the consumption of quinoa might reduce the risk of cardiovascular diseases, obesity, diabetes, cancer, and menopausal disorders.
In this study, we clarified the effects of NaCl application on the growth and Cs absorption in quinoa (Chenopodium quinoa Willd.). Pot experiments using Wagner pots (1/5000a) were conducted in an experimental field at Nihon University during 2014, 2015, and 2016, using quinoa variety CICA-127. Growth of quinoa and Cs absorption by quinoa were promoted by the application of NaCl. The Cs content of aboveground parts of plants was also increased by the application of NaCl; however, the differences in Cs content among plots were not significant. Thus, the reason for the increase in Cs absorption was the promotion of biomass by the application of NaCl. The exchangeable K content in the soil and the growth of quinoa were increased by the application of KCl. Therefore, increasing the exchangeable K content in soil by the application of KCl has contributed to the increased accumulation of K and the decreased accumulation of Cs in the aboveground parts of plants. Thus, the lower exchangeable K content in soil led to a lower plant K content and a greater absorption of Cs by quinoa.
Hossein-Pour et al.: Genetic diversity and population structure of quinoa (Chenopodium quinoa Willd.) using iPBS-retrotransposons markers-1899-APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 17(2):1899-1911. Abstract. Quinoa (Chenopodium quinoa Willd.) is a nutritionally important plant with a good protein quality and a high concentration of vitamins and minerals. It has been cultured for several thousand years in South America. In this study, we investigated the use of inter-primer binding site (iPBS) for the molecular characterization of 17 quinoa genotypes (Chenopodium quinoa Willd.) cultivated in Turkey. For this purpose, 25 iPBS markers were employed, and six primers provided sufficient polymorphic data generating a total of 19 alleles with an average of 2.83 bands/primer. The number of iPBS bands per individual was calculated as 1.12. The rate of polymorphism information content ranged from 0.02 to 0.49 with an average of 0.20. Genetic associations were assessed using the Dice dissimilarity coefficient between different pairs of accessions and revealed an average value of 0.84 for the French population and Q-52 genotypes. Cluster analysis on the unweighted pair-group mean average divided the 17 quinoa genotypes into two major clusters. The results of the principal component analysis were in agreement with those of the cluster analysis. The highest number of alleles, Nei's genetic diversity, and Shannon's information index were obtained from the French Vanilla genotype at 1.99, 0.50 and 0.69, respectively, whereas the lowest values were observed in the Q-52 genotype at 1.10, 0.09 and 0.20, respectively. The expected heterozygosity ranged from 0.398 in the first sub-population to 0.140 in the second sub-population with an average of 0.269. The mean population differentiation measurement (Fst) values of the sub-populations were 0.048 and 0.676 for the first and second sub-populations, respectively. The results of this study provide useful information for the management of the quinoa germplasm and contribute to the improvement of existing breeding approaches. They also presented the iPBS marker system as a suitable tool for identification and genetic diversity analysis of quinoa genotypes.
Abstract Quinoa has recently gained international attention because of its nutritious seeds, prompting the expansion of its cultivation into new areas in which it was not originally selected as a crop. Improving quinoa production in these areas will benefit from the introduction of advantageous traits from free-living relatives that are native to these, or similar, environments. As part of an ongoing effort to characterize the primary and secondary germplasm pools for quinoa, we report the complete mitochondrial and chloroplast genome sequences of quinoa accession PI 614886 and the identification of sequence variants in additional accessions from quinoa and related species. This is the first reported mitochondrial genome assembly in the genus Chenopodium. Inference of phylogenetic relationships among Chenopodium species based on mitochondrial and chloroplast variants supports the hypotheses that 1) the A-genome ancestor was the cytoplasmic donor in the original tetraploidization event, and 2) highland and coastal quinoas were independently domesticated.
Abstract Quinoa has been highlighted as a promising crop to sustain food security. The selection of physiological traits that allow identification genotypes with high Nitrogen use efficiency (NUE) is a key factor to increase Quinoa cultivation. In order to unveil the underpinning mechanisms for N-stress tolerance in Quinoa, three genotypes with similar phenology, but different NUE were developed under high (HN) or low (LN) nitrogen conditions. N metabolism processes and photosynthetic performance were studied after anthesis and in correlation with productivity to identify principal traits related to NUE. We found that protein content, net photosynthesis and leaf dry-mass were determinant attributes for yield at both HN and LN conditions. Contrastingly, the enhancement of N related metabolites ( NH4+ , proline, betacyanins) and processes related with re-assimilation of NH4+ , including an increment of glutamine synthetase activity and up-regulation of CqAMT1,1 transporter expression in leaves, were negatively correlated with grain yield at both N conditions. Biochemical aspects of photosynthesis and root biomass were traits exclusively associated with grain yield at LN. The impact of N supply on seed quality is discussed. These results provide new insights towards the understanding the N metabolism of Quinoa.
Quinoa (Chenopodium quinoa Willd.) is a genetically diverse Andean crop that has earned special attention worldwide due to its nutritional and health benefits and its ability to adapt to contrasting environments, including nutrient-poor and saline soils and drought stressed marginal agroecosystems. Drought and salinity are the abiotic stresses most studied in quinoa; however, studies of other important stress factors, such as heat, cold, heavy metals, and UV-B light irradiance, are severely limited. In the last few decades, the incidence of abiotic stress has been accentuated by the increase in unpredictable weather patterns. Furthermore, stresses habitually occur as combinations of two or more. The goals of this review are to: (1) provide an in-depth description of the existing knowledge of quinoa's tolerance to different abiotic stressors; (2) summarize quinoa's physiological responses to these stressors; and (3) describe novel advances in molecular tools that can aid our understanding of the mechanisms underlying quinoa's abiotic stress tolerance.
En el departamento del Cauca, municipio de Puracé vereda El acuario, localizado a 3023 m.s.n.m., en el marco del proyecto Cadena productiva de la quinua se evaluó el ciclo fenológico de 4 ecotipos de quinua y su rendimiento con el fin de seleccionar y determinar la duración de las etapas del ciclo productivo que determinan su manejo agronómico en alturas superiores a 3000 m.s.n.m. El propósito es buscar una opción para rotación de cultivo de papa que aporte a la seguridad alimentaria regional. Este estudio se realizó durante el 2016 bajo condiciones de campo, en el resguardo indígena de Paletará. Se utilizó un diseño de bloques completos al azar con 3 repeticiones donde los tratamientos fueron los ecotipos, se registraron etapas fenológicas, se evaluó contenido de saponinas y el rendimiento. Se determinó que la quinua presenta dos etapas fenológicas bien marcadas, etapa vegetativa con 6 fases y etapa reproductiva con 7 fases; la duración del ciclo productivo de los 4 ecotipos estuvo entre 154 y 213, permitiendo clasificarlos como semiprecoces y semitardios, el contenido de saponinas estuvo entre 0,005 y 0,012%. Se concluyó que de los 4 ecotipos evaluados se recomienda aurora por precocidad, sabor dulce y mejor rendimiento.
Background
Salinity is a global issue threatening agricultural production systems across the globe. While the major focus of plant salinity stress tolerance research has been on sodium, the transport and physiological roles of K+ in plant salt stress response has received less attention. This review attempts to bridge this knowledge gap.
Scope
The major emphasis is on newly proposed K+ signalling roles and plant salt tolerance cell- and tissuespecificity. In addition to summarizing the importance of K+ retention for plant salt tolerance, we focus onaspects that were not the subject of previous reviews including (1) the importance of HAK/KUP family of transporters in K+ uptake in salt stressed plants and its possible linkage with Ca2+ and ROS signalling; (2) control of xylem K+ loading in salt stressed plants, control of phloem K+ recirculation in salt stressed plants and the potential importance of plant’s ability to efficiently coordinate K+ signals between root and shoot; (3) the buffering capacity of the vacuolar K+ pool; and (4) mechanisms of restoring the basal cytosolic K+ levels by coordinated activity of tonoplast K+-permeable channels.
Conclusions
Overall, this review emphasises the need to fully understand the newly emerging roles of K+ and regulation of its transport for improving salinity stress tolerance in plants.
The TIFY proteins constitute a plant-specific super-family and they are involved in regulating many plant processes, such as development, defences and stress responses. The Jasmonate-ZIM-Domain (JAZ) proteins, the best-characterized sub-group of the TIFY family are key regulator of the jasmonic acid (JA) signalling pathway. Jasmonates regulate several aspects of plant development, and play a primary role in defence mechanisms as well as in plant responses to abiotic stresses. The TIFY family is well studied in dicots but poorly investigated in monocots. The present study reports an extensive genomic identification of TIFY proteins from Triticum aestivum. We identified 49 TIFY genes, which were annotated according to three sub-genomes (AABBDD) of T. aestivum. Following their clustering with Oryza sativa and Brachypodium distachyon, the 49 genes were grouped in 18 different TIFY homeologous subsets. Expression analyses of 6 representative TIFY genes on Tunisian durum wheat seedlings revealed their differential regulation by various stress treatment, including JA, ABA and salt stress. TIFY11a was specifically induced after salt treatment. Transgenic lines over-expressing TdTIFY11a showed higher germination and growth rates under high salinity conditions, compared to wild type plants. In summary, our results outline a relevant role of wheat TIFY proteins in promoting germination under salt stress.
Heat shock transcription factor (Hsf) is one of the conserved gene families in plants, playing a crucial role in growth and development, as well as in response to diverse stresses. Although it has been systematically studied in many species, little is known about the Hsf gene family in Chenopodium quinoa, especially those involved in the regulatory network of stress processes. In this study, we identified 23 Hsf genes in quinoa (CqHsfs) through a genome-wide search method based on the latest available genome information. Phylogenetic analysis classified them into three groups, and group A was further divided into nine subgroups, which was supported by conserved domain organizations. Gene structure and multiple sequence alignment analysis revealed that all of the CqHsfs possessed a similar structure organization and were highly conserved in BDB domain. Interaction network analysis identified 13 CqHsfs involved in the network pathway to regulate diverse biological processes. Expression profiles of these CqHsfs were further investigated using the RNA-seq data, and tissue-specific and stress-responsive candidates were identified. Finally, four heat-responsive CqHsfs were selected to validate their expression level through semi-quantitative RT-PCR analysis. This study reported the organization, structure, and expression profiles of the Hsf gene family in quinoa, which will contributes to further functional analysis, and helps to better understand the roles and regulatory mechanism of heat shock factors playing in quinoa and beyond.
Quinoa (Chenopodium quinoa Willd.) is a highly resilient crop, displaying high levels of salinity and drought tolerance, although only low levels of heat tolerance. In this chapter, current knowledge of the response of quinoa to abiotic stresses is discussed, focussing on physiological responses, putative molecular mechanisms and genetic control. Relatively little research has been conducted into quinoa, and even less has been done to elucidate the genetics underpinning quinoa’s tolerance to abiotic stresses. The quinoa genes CqSOS1, CqNHX1, CqBADH, CqHSP70, CqHSP20 and CqABAs are discussed, and areas requiring further research at the genetic level are highlighted. There are currently extensive gaps in our understanding of the response of quinoa to certain abiotic stresses, with virtually no studies covering the effects of soil acidity, boron toxicity and nutrient deficiency. Whilst there is significant genetic diversity within the quinoa species, significant research is required to understand how this genetic variation can be harnessed. The recent release of a high-quality quinoa reference genome provides a useful tool to greatly facilitate the characterisation of genes involved in abiotic stress tolerance and taking a genetics-led approach should aid the rapid advancement of our understanding of quinoa’s abiotic stress tolerance mechanisms and lead to more effective improvement in engineering and breeding strategies. With these improvements, quinoa can fulfil a role urgently needed to provide food security in arid and semi-arid regions.
Cereals are considered as an important source of nutrition in human diet. They provide about
half of the energy of world population. Cereals include maize, rice, wheat, sorghum, barley, oats
and rye. Other grains like amaranth, quinoa, chia, buckwheat and flaxseed have also been
studied due to their extreme nutritional values and high protein profiles. These grains plants are
excellent source of the energy, lipids, fibers, vitamins, minerals, proteins, ashes and amino acids.
Quinoa is one of them and is excellent source of lysine and niacin. It is rich in essential amino
acid content. It also has antioxidant agents that perform good function in the human body when
consumed. Quinoa is also a well natural source that is helpful to combat against Celiac disease.
In this review, we shall discuss the different nutritional benefits of quinoa.
Many areas of the world are affected simultaneously by salinity and heavy metal pollution. Halophytes are considered as useful candidates in remediation of such soils due to their ability to withstand both osmotic stress and ion toxicity deriving from high salt concentrations. Quinoa (Chenopodium quinoa Willd) is a halophyte with a high resistance to abiotic stresses (drought, salinity, frost), but its capacity to cope with heavy metals has not yet been fully investigated. In this pot experiment, we investigated phytoextraction capacity, effects on nutrient levels (P and Fe), and changes in gene expression in response to application of Cr(III) in quinoa plants grown on saline or non-saline soil. Plants were exposed for three weeks to 500 mg kg-1 soil of Cr(NO3)3·9H2O either in the presence or absence of 150 mM NaCl. Results show that plants were able tolerate this soil concentration of Cr(III); the metal was mainly accumulated in roots where it reached the highest concentration (ca. 2.6 mg g-1 DW) in the presence of NaCl. On saline soil, foliar Na concentration was significantly reduced by Cr(III). Phosphorus translocation to leaves was reduced in the presence of Cr(III), while Fe accumulation was enhanced by treatment with NaCl alone. A real-time RT-qPCR analysis was conducted on genes encoding for sulfate, iron, and phosphate transporters, a phytochelatin, a metallothionein, glutathione synthetase, a dehydrin, Hsp70, and enzymes responsible for the biosynthesis of proline (P5CS), glycine betaine (BADH), tocopherols (TAT), and phenolic compounds (PAL). Cr(III), and especially Cr(III)+NaCl, affected transcript levels of most of the investigated genes, indicating that tolerance to Cr is associated with changes in phosphorus and sulfur allocation, and activation of stress-protective molecules. Moderately saline conditions, in most cases, enhanced this response, suggesting that the halophytism of quinoa could contribute to prime the plants to respond to chromium stress.
Se describen los efectos de la radiación UV-B (RUV-B) sobre algunos parámetros de crecimiento: altura de la planta (A), diámetro de tallo (DT), largo x ancho (LA), número de hojas (NH), área foliar específica (AFE) y masa foliar específica (MFE) en cinco variedades de quinoa. Los efectos de la UV-B fueron diferentes según la variedad y parámetro considerado. Así, A se incrementó en las variedades CICA (P ? 0,04) y Robura (P ? 0,02); mientras DT fue influenciado positivamente en CICA (P ? 0,0002) y Faro Roja (P ? 0,017). LA sólo mostró cambios significativos (P ? 0,05) en CICA. El NH fue la variable que experimentó cambios positivos en todas las variedades, observándose los más pronunciados en Faro Roja (P ? 0,003), CICA (P ? 0,003) y Ratuqui (P ? 0,015). La MFE cambió positivamente en Faro Roja, Kancolla y Robura (P ? 0,05). CICA fue la única variedad que experimentó incrementos significativos en todos los parámetros evaluados, seguida de Faro Roja y Robura. El menor porcentaje de cambios ocurrieron en Kancolla y Ratuqui. Las variaciones observadas se discutieron en términos de adaptación evolutiva.
Quinoa is well known for its great ability to tolerate water stress. However, very little information is available about its potential growth under full irrigation particularly in hot and semi-arid regions. In this experiment, a newly-released quinoa (cv. Q5) bred for hot and dry regions was grown under three planting densities (PDs) of 150,000, 185,000, and 270,000 in the drainable lysimeters, south of Iran. The highest and lowest grain yields were observed in the middle and low PDs of 3.65 Mg ha −1 and 2.86 Mg ha −1 , respectively. Quinoa showed very high crop evapotranspiration (ETc) and transpiration (T) rates. ETc and T varied in the range of 1448-1687 mm, and 777-1228 mm among the PDs, respectively. These high values resulted in high single crop coefficients (Kc) that overall varied between around 1 and 2.4 during the growing season. The basal crop coefficient (Kcb) of the dual Kc (Kc = Kcb + Ke) reached about 1.9 and 1.2 in the high and low PDs, respectively, indicating high transpiration capacity. The main reasons of high Kc and Kcb were high soil evaporation rate due to very frequent irrigations of 3-4 days and soil wetting, and the prevailing regional sensible heat advection that increased transpiration. It was concluded that quinoa has a specific physiological systems that transpire continually for allowing better leaf cooling at high temperature, which results in high water use. Moreover, a vigorous root system that extended down to 1.2 m with high root length densities in the deep layers (RLD > 1 cm cm-3) helped quinoa to supply the water use. This extensive root system down to 1.2 m could help to increase irrigation interval and reducing soil evaporation. However, the effect of PD on the root length and root mass was mainly observed in the top 40 cm, below which its effect diminished and root length and root mass were nearly identical among the PDs. Overall, it is concluded that quinoa Q5 is a super crop that not only can tolerate water stress, but also can potentially grow well and produce acceptable grain yield in the hot and semi-arid areas. Adapting appropriate PD and irrigation management such as drip irrigation (surface and subsurface), mulching, increasing irrigation interval attributed to the deep rooting system, and water-saving irrigation managements would substantially reduce soil evaporation and increase water productivity.
Hybridization and polyploidization appear to be ubiquitous in the evolution of Chenopodium s.s., but the origin and the evolutionary history of the polyploid chenopods is still poorly understood. Phylogenetic analyses of DNA sequences of nrITS, four plastid regions, and 5S rDNA spacer region (NTS) of five Eurasian hexaploid chenopods (2n = 6x = 54), C. album, C. giganteum, C. pedunculare C. formosanum and C. opulifolium, and their diploid and tetraploid relatives as well as genomic in situ hybridization (GISH) indicate their allohexaploid origin. The origin of all the analyzed hexaploids have been inferred to have involved B-genome diploid. The identity of the other parent/parents is more elusive. In the case of C. album, C. giganteum and C. pedunculare the second maternal parent seems to be similar to extant C. strictum or C. striatiforme or Asian diploids (e.g. C. acuminatum). In genomes of allohexaploid C. album, C. giganteum and C. pedunculare half of the rDNA were located in the chromosomes of B-subgenome. The remaining rDNA loci were placed in chromosomes originating from the other parent/parents. Although 35S rDNA loci inherited from two parental species seems to be present in these hexaploids, only one ribotype of nrITS was detected.
Quinoa has been widely used as a model crop for understanding salt-tolerance in halophyte plants. However, a salt tolerance mechanism regarding the photosynthetic activity is poorly evaluated. Here we report the effects of salt stress on photosynthesis of the halophyte Chenopodium quinoa cultivated under different NaCl concentrations (0, 100, and 300 mM). Our results revealed no apparent effect of moderate salinity (100 mM NaCl) on plant growth while, a reduction of plant biomass production was detected under 300 mM NaCl without any symptom of toxicity. No significant effect on the chloroplasts ultrastructure was observed under moderate salinity. Some morphological deformations of chloroplasts such as swelling of thylakoids, disruption of envelope, accumulation of starch grains and plastoglobuli were observed following prolonged exposure to severe stress. Under moderate salinity, no considerable change was detected on the rate of primary photochemistry (fluorescence O-J phase) and the reduction of the PQ pool (J-I phase), no apparent effects on the minimal (F 0 ), the maximal fluorescence (F m ) and the maximal photochemical efficiency (Fv/Fm) showing a high stability of PSII. The high PSII efficiency was also confirmed by the donor side intactness (constant Fk/Fj ratio) and stable antenna size. The high stability of PSII efficiency was also demonstrated by enhanced communication between antenna complex and PSII reaction centre and the stability of OEC complex (PsbQ and PsbO proteins). However, high salinity (300 mM NaCl) results in a swelling of thylakoids and disappearance of grana and in a decrease of Fm and (Fv/Fm) leading to the down-regulation of PSII activity. In addition, a significant increase in F0 occurred and could be associated to the presence of some Q A⁻ in darkness in equilibrium with a partially reduced PQ pool. High salt treatment could be responsible for the thermal phase which induced an increase in chl a fluorescence (JIP rise with oxidized PQ pool).
Soil salinity is destroying arable land and is considered to be one of the major threats to global food security in the 21st century. Therefore, the ability of naturally salt-tolerant halophyte plants to sequester large quantities of salt in external structures, such as epidermal bladder cells (EBCs), is of great interest. Using Chenopodium quinoa, a pseudo-cereal halophyte of great economic potential, we have shown previously that, upon removal of salt bladders, quinoa becomes salt sensitive. In this work, we analyzed the molecular mechanism underlying the unique salt dumping capabilities of bladder cells in quinoa. The transporters differentially expressed in the EBC transcriptome and functional electrophysiological testing of key EBC transporters in Xenopus oocytes revealed that loading of Na+ and Cl- into EBCs is mediated by a set of tailored plasma and vacuole membrane-based sodium-selective channel and chloride-permeable transporter.
Quinoa (Chenopodium quinoa Willd.) has gained considerable attention worldwide during the past decade due to its nutritional and health benefits. However, its susceptibility to high temperatures has been reported as a serious obstacle to its global production. The objective of this study was to evaluate quinoa growth and pollen morphology in response to high temperatures. Pollen morphology and viability, plant growth and seed set, and several physiological parameters were measured at anthesis in two genotypes of quinoa subjected to day/night temperatures of 22/16°C as a control treatment and 40/24°C as the heat stress treatment. Our results showed that heat stress reduced the pollen viability between 30% and 70%. Although no visible morphological differences were observed on the surface of the pollen between the heat‐stressed and non‐heat‐stressed treatments, the pollen wall (intine and extine) thickness increased due to heat stress. High temperature did not affect seed yield, seed size and leaf greenness. On the other hand, high temperature improved the rate of photosynthesis. We found that quinoa has a high plasticity in response to high temperature, though pollen viability and pollen wall structure were affected by high temperatures in anthesis stage. This study is also the first report of quinoa pollen being trinucleate.