Analysis of widely targeted metabolites of quinoa sprouts (Chenopodium quinoa Willd.) under saline-alkali stress provides new insights into nutritional value.

Quinoa sprouts are a green vegetable rich in bioactive chemicals, which have multiple health benefits. However, there is limited information on the overall metabolic profiles of quinoa sprouts and the metabolite changes caused by saline-alkali stress. Here, a UHPLC-MS/MS-based widely targeted metabolomics technique was performed to comprehensively evaluate the metabolic profiles of quinoa sprouts and characterize its metabolic response to saline-alkali stress. A total of 930 metabolites were identified of which 232 showed significant response to saline-alkali stress. The contents of lipids and amino acids were significantly increased, while the contents of flavonoids and phenolic acids were significantly reduced under saline-alkali stress. Moreover, the antioxidant activities of quinoa sprouts were significantly affected by saline-alkali stress. The enrichment analysis of the differentially accumulated metabolites revealed that flavonoid, amino acid and carbohydrate biosynthesis/metabolism pathways responded to saline-alkali stress. This study provided an important theoretical basis for evaluating the nutritional value of quinoa sprouts and the changes in metabolites in response to saline-alkali stress.

Leaf and shoot apical meristem transcriptomes of quinoa (Chenopodium quinoa Willd.) in response to photoperiod and plant development.

Understanding the regulation of flowering time is crucial for adaptation of crops to new environment. In this study, we examined the timing of floral transition and analysed transcriptomes in leaf and shoot apical meristems of photoperiod-sensitive and -insensitive quinoa accessions. Histological analysis showed that floral transition in quinoa initiates 2-3 weeks after sowing. We found four groups of differentially expressed genes in quinoa genome that responded to plant development and floral transition: (i) 222 genes responsive to photoperiod in leaves, (ii) 1812 genes differentially expressed between accessions under long-day conditions in leaves, (iii) 57 genes responding to developmental changes under short-day conditions in leaves and (iv) 911 genes responding to floral transition within the shoot apical meristem. Interestingly, among numerous candidate genes, two putative FT orthologs together with other genes (e.g. SOC1, COL, AP1) were previously reported as key regulators of flowering time in other species. Additionally, we used coexpression networks to associate novel transcripts to a putative biological process based on the annotated genes within the same coexpression cluster. The candidate genes in this study would benefit quinoa breeding by identifying and integrating their beneficial haplotypes in crossing programs to develop adapted cultivars to diverse environmental conditions.

Exogenous application of moringa leaf extract improves growth, biochemical attributes, and productivity of late-sown quinoa.

Quinoa (Chenopodium quinoa Willd.) has gained significant popularity among agricultural scientists and farmers throughout the world due to its high nutritive value. It is cultivated under a range of soil and climatic conditions; however, late sowing adversely affects its productivity and yield due to shorter growth period. Inorganic and organic phyto-stimulants are promising for improving growth, development, and yield of field crops under stressful environments. Field experiments were conducted during crop cultivation seasons of 2016-17 and 2017-18, to explore the role of inorganic (hydrogen peroxide and ascorbic acid) and organic [moringa leaf extract (MLE) and sorghum water extract (sorgaab)] phyto-stimulants in improving growth and productivity of quinoa (cultivar UAF-Q7). Hydrogen peroxide at 100 µM, ascorbic acid at 500 µM, MLE at 3% and sorgaab at 3% were exogenously applied at anthesis stage of quinoa cultivated under normal (November 21st and 19th during 2016 and 2017) and late-sown (December 26th and 25th during 2016 and 2017) conditions. Application of inorganic and organic phyto-stimulants significantly improved biochemical, physiological, growth and yield attributes of quinoa under late sown conditions. The highest improvement in these traits was recorded for MLE. Application of MLE resulted in higher chlorophyll a and b contents, stomatal conductance, and sub-stomatal concentration of CO2 under normal and late-sowing. The highest improvement in soluble phenolics, anthocyanins, free amino acids and proline, and mineral elements in roots, shoot and grains were observed for MLE application. Growth attributes, including plant height, plant fresh weight and panicle length were significantly improved with MLE application as compared to the rest of the treatments. The highest 1000-grain weight and grain yield per plant were noted for MLE application under normal and late-sowing. These findings depict that MLE has extensive crop growth promoting potential through improving physiological and biochemical activities. Hence, MLE can be applied to improve growth and productivity of quinoa under normal and late-sown conditions.

Developing Chenopodium ficifolium as a potential B genome diploid model system for genetic characterization and improvement of allotetraploid quinoa (Chenopodium quinoa).

BACKGROUND: Quinoa (Chenopodium quinoa) is a high-value grain known for its excellent nutritional balance. It is an allotetraploid species (AABB, 2n = 4x = 36) formed by the hybridization between AA and BB genome diploid (2n = 2x = 18) species. This study reports genetic studies in Chenopodium ficifolium as a potential B genome diploid model system to simplify the genetic studies of quinoa including gene identification and marker-assisted breeding. RESULTS: Portsmouth, New Hampshire and Quebec City, Quebec accessions of C. ficifolium were used to develop an F2 population segregating for agronomically relevant traits including flowering time, plant height, the number of branches, branch angle, and internode length. Marker-trait associations were identified for the FLOWERING LOCUS T-LIKE 1 (FTL1) marker gene, where the alternate alleles (A1/A2) were segregating among the F2 generation plants in association with flowering time, plant height, and the number of branches. There was a strong correlation of the flowering time trait with both plant height and the number of branches. Thus, a possible multifaceted functional role for FTL1 may be considered. The parental Portsmouth and Quebec City accessions were homozygous for the alternate FTL1 alleles, which were found to be substantially diverged. SNPs were identified in the FTL1 coding sequence that could have some functional significance in relation to the observed trait variation. CONCLUSION: These results draw further attention to the possible functional roles of the FTL1 locus in Chenopodium and justify continued exploration of C. ficifolium as a potential diploid model system for the genetic study of quinoa. We expect our findings to aid in quinoa breeding as well as to any studies related to the Chenopodium genus.

Silicon mitigates nutritional stress in quinoa (Chenopodium quinoa Willd.).

Nutritional deficiency is common in several regions of quinoa cultivation. Silicon (Si) can attenuate the stress caused by nutritional deficiency, but studies on the effects of Si supply on quinoa plants are still scarce. Given this scenario, our objective was to evaluate the symptoms in terms of tissue, physiological and nutritional effects of quinoa plants submitted to nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) deficiencies under Si presence. The experiment consisted of a factorial scheme 6 × 2, using a complete solution (CS), -N, -P, -K, -Ca, -Mg combined with absence and presence of Si (1.5 mmol L-1). Symptomatic, physiological, nutritional and evaluation vegetative were performed in quinoa crop. The deficiencies of N, P, K, Ca and Mg in quinoa cultivation caused visual symptoms characteristic of the deficiency caused by respective nutrients, hence decreasing the plant dry mass. However, Si supply attenuated the deficiency effects by preserving the photosynthetic apparatus, increasing the chlorophyll production, increasing the membrane integrity, and decreasing the electrolyte leakage. Thus, the Si supply attenuated the visual effects provided by deficiency of all nutrients, but stood out for N and Ca, because it reflected in a higher dry mass production. This occurred because, the Si promoted higher synthesis and protection of chlorophylls, and lower electrolyte leakage under Ca restriction, as well as decreased electrolyte leakage under N restriction.

Chemical components and chain-length distributions affecting quinoa starch digestibility and gel viscoelasticity after germination treatment.

A germination treatment was explored in this study as a green strategy to reduce the in vitro starch digestibility of cooked quinoa. The alterations of chemical compositions, starch chain-length distributions (CLDs) and rheological characteristics of quinoa flours after the germination treatment were characterized. Results showed that a significant alteration of amylose CLDs and the starch digestibility was observed for cooked quinoa flours after different germination times. By fitting starch digestograms to the logarithm of slop (LOS) plot and the combination of parallel and sequential kinetics model (CPS), two starch digestible fractions with distinct rate constants were identified. Pearson correlation analysis further found that the observed starch digestive characteristics could be largely explained by the alterations of amylose CLDs caused by the germination treatment. More specifically, the rapidly digestible starch fraction mainly consisted of amorphous amylopectin molecules and amylose intermolecular crystallites. On the other hand, the slowly digestible starch fraction was largely formed by intramolecular interactions among amylose short chains (degree of polymerization (DP) < 500). These results suggest that germination may be a promising way to develop cereal products with slower starch digestibility.

A multilayered cross-species analysis of GRAS transcription factors uncovered their functional networks in plant adaptation to the environment.

Introduction: Environmental stress is both a major force of natural selection and a prime factor affecting crop qualities and yields. The impact of the GRAS [gibberellic acid-insensitive (GAI), repressor of GA1-3 mutant (RGA), and scarecrow (SCR)] family on plant development and the potential to resist environmental stress needs much emphasis. Objectives: This study aims to investigate the evolution, expansion, and adaptive mechanisms of GRASs of important representative plants during polyploidization. Methods: We explored the evolutionary characteristics of GRASs in 15 representative plant species by systematic biological analysis of the genome, transcriptome, metabolite, protein complex map and phenotype. Results: The GRAS family was systematically identified from 15 representative plant species of scientific and agricultural importance. The detection of gene duplication types of GRASs in all species showed that the widespread expansion of GRASs in these species was mainly contributed by polyploidization events. Evolutionary analysis reveals that most species experience independent genome-wide duplication (WGD) events and that interspecies GRAS functions may be broadly conserved. Polyploidy-related Chenopodium quinoa GRASs (CqGRASs) and Arabidopsis thaliana GRASs (AtGRASs) formed robust networks with flavonoid pathways by crosstalk with auxin and photosynthetic pathways. Furthermore, Arabidopsis thaliana population transcriptomes and the 1000 Plants (OneKP) project confirmed that GRASs are components of flavonoid biosynthesis, which enables plants to adapt to the environment by promoting flavonoid accumulation. More importantly, the GRASs of important species that may potentially improve important agronomic traits were mapped through TAIR and RARGE-II publicly available phenotypic data. Determining protein interactions and target genes contributes to determining GRAS functions. Conclusion: The results of this study suggest that polyploidy-related GRASs in multiple species may be a target for improving plant growth, development, and environmental adaptation.

Hormesis effects of gamma radiation on growth of quinoa (Chenopodium quinoa).

PURPOSE: Quinoa is an annual plant that grows well in high altitude regions with high radiation and ultraviolet intensity. It has known that high-dose radiation damages living organisms, but low-dose radiation also has a beneficial effect. Therefore, the purpose of this study is to investigate the hormesis effect of gamma-ray on quinoa by growth analysis and hyperspectral imaging. MATERIALS AND METHODS: Quinoa seeds were irradiated at 50, 100, and 200 Gy emitted by 60CO. Subsequently, the seeds were germinated and transplanted into pots, then conducted growth analysis and physiological evaluation every week, and hyperspectral imaging. Photosynthetic ability was measured at 35 days after transplanting (DAT), and the plants for each dose were divided into aerial and underground parts for biomass evaluation at 91 DAT. Various vegetation indices were estimated from 14 to 35 DAT by hyperspectral analysis, and the specific bands were extracted based on the PLS model using plant height, SPAD value, and chlorophyll fluorescence parameters. RESULTS: We found that plant height and biomass were increased in quinoa plants treated with a low dose (50 Gy) as compared to control. Chlorophyll content and chlorophyll fluorescence were not different between doses at the early growth stage, but as growth progressed, the plant irradiated at 200 Gy began to be lower. The photosynthetic ability of the quinoa plant treated at 50 Gy was greater than other plants at 35 DAT. The vegetation indices related to the pigment status also were higher in the plants treated by irradiation at 50 Gy than the plants grown in other doses treatment units at the beginning of the growth. Using the PLS model we collected sensitive band wavelengths from hyperspectral image analysis. Among the collected bands, eight bands closely related to plant height, nine bands to chlorophyll content, and ten bands to chlorophyll fluorescence were identified. CONCLUSION: Our results showed that the growth and physiological parameters of quinoa treated by low dose gamma irradiation to seeds were greater than that of control as well as the plant with higher doses. These findings confirm that the positive changes in the characteristics of quinoa with low dose radiation indicated that hormesis occurs at 50 Gy radiation.

Impact of germination on phenolic composition, antioxidant properties, antinutritional factors, mineral content and Maillard reaction products of malted quinoa flour.

The study aimed at improving and comparing the nutritional profile of black (BQ) and white quinoa (WQ) through malting at different germination periods (24, 48, 72 and 96 h), followed by drying at 50 °C, decluming, grinding and sieving to obtain malt flour. The changes in protein, reducing sugar, Maillard reaction products (MRPs), minerals, free and bound polyphenols and antioxidant activity were noted. Malting caused significant increase in polyphenolic content, antioxidant capacity and fluorescence of advanced MRP (FAST) index. The highest increment was noted in malts germinated for 48 and 72 h. BQ malts were marked by higher bound hydroxycinnamic acids, flavan-3-ols, magnesium, potassium and antioxidant activity, while, WQ malts had lower saponin, phytic acid but higher protein, iron, calcium, FAST index. WQ exhibited highest increment (27.23%) in antioxidant activity even though it had lower polyphenols than BQ after malting. Major loss in polyphenols and proteins occurred in malt germinated for 96 h.

Salinity Effects on Guard Cell Proteome in Chenopodium quinoa.

Epidermal fragments enriched in guard cells (GCs) were isolated from the halophyte quinoa (Chenopodium quinoa Wild.) species, and the response at the proteome level was studied after salinity treatment of 300 mM NaCl for 3 weeks. In total, 2147 proteins were identified, of which 36% were differentially expressed in response to salinity stress in GCs. Up and downregulated proteins included signaling molecules, enzyme modulators, transcription factors and oxidoreductases. The most abundant proteins induced by salt treatment were desiccation-responsive protein 29B (50-fold), osmotin-like protein OSML13 (13-fold), polycystin-1, lipoxygenase, alpha-toxin, and triacylglycerol lipase (PLAT) domain-containing protein 3-like (eight-fold), and dehydrin early responsive to dehydration (ERD14) (eight-fold). Ten proteins related to the gene ontology term "response to ABA" were upregulated in quinoa GC; this included aspartic protease, phospholipase D and plastid-lipid-associated protein. Additionally, seven proteins in the sucrose-starch pathway were upregulated in the GC in response to salinity stress, and accumulation of tryptophan synthase and L-methionine synthase (enzymes involved in the amino acid biosynthesis) was observed. Exogenous application of sucrose and tryptophan, L-methionine resulted in reduction in stomatal aperture and conductance, which could be advantageous for plants under salt stress. Eight aspartic proteinase proteins were highly upregulated in GCs of quinoa, and exogenous application of pepstatin A (an inhibitor of aspartic proteinase) was accompanied by higher oxidative stress and extremely low stomatal aperture and conductance, suggesting a possible role of aspartic proteinase in mitigating oxidative stress induced by saline conditions.

Synergistic consequences of salinity and potassium deficiency in quinoa: Linking with stomatal patterning, ionic relations and oxidative metabolism.

Quinoa emerged as an ideal food security crop due to its exceptional nutritive profile and stress enduring potential and also deemed as model plant to study the salt-tolerance mechanisms. However to fill the research gaps of this imperative crop, the present work aimed to study the effect of potassium (K) deficiency either separately or in combination with salinity. First, we investigated the stomatal and physiological based variations in quinoa growth under salinity and K, then series of analytical tools were used with model approach to interpret the stomatal aperture (SA) and photosynthesis (Pn) changes. Results revealed that quinoa efficiently deployed antioxidants to scavenge the excessive reactive oxygen species (ROS), had high uptake and retention of K+, Ca2+, Mg2+ with Cl⁻ as charge balancing ion, increased stomata density (SD) and declined the SA to maintain the Pn which resulted the improved growth under salinity. Whereas, K-deficiency caused the stunted growth more severally under salinity due to disruption in ionic homeostasis, excessive ROS production elicited the oxidative damages, SD and SA reduced and ultimately declined in Pn. Our best fitted regression model explored that dependent variables like Pn and SA changed according to theirs signified explanatory variables with quantification per unit based as stomatal conductance (Gs, 51), SD (0.05), ROS (-0.79) and K+ (0.08), Cl⁻ (0.34) and Na+ (- 0.52) respectively. Overall, moderate salinity promoted the quinoa growth, while K-deficiency particularly with salinity reduced the quinoa performance by affecting stomatal and non-stomatal factors.

The hyperglycemic regulatory effect of sprouted quinoa yoghurt in high-fat-diet and streptozotocin-induced type 2 diabetic mice via glucose and lipid homeostasis.

Recently, we have proposed that quinoa yoghurt (QY) has the anti-diabetic properties based on an in vitro study. Here, its antidiabetic activity was further validated by investigating its hypoglycemic and hypolipidemic influence in high fat diet/streptozotocin-induced type 2 diabetes mellitus (T2DM) mice. The results showed that QY increased the body weights of and reduced the fasting blood glucose levels in T2DM mice. QY significantly (p < 0.05) reduced the serum levels of total cholesterol, triglyceride and LDL-C, while it increased the HDL-C level. In addition, the hepatic glycogen content, and superoxide dismutase, catalase, and glutathione peroxidase activities were significantly (p < 0.05) increased, while lipid peroxidation was remarkably reduced. Sprouted QY had the highest influence on serum oxidation when compared with non-germinated QY. The level of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) were significantly (p < 0.05) decreased, while the level of anti-inflammatory cytokine IL-10 was increased. Histopathological studies showed that QY protected the tissue structure of the liver of T2DM mice. Immunohistochemistry showed that QY increased AKT-2 and AMPK-α2 expressions, while it suppressed p85. The qRT-PCR analysis indicated that QY exerted its hypoglycemic and anti-hyperlipidemic effects through the AKT/AMPK/PI3K signaling pathway. Germination significantly (p < 0.05) influenced the glucose and lipid homeostasis in T2DM mice in such a way that sprouted QY showed the highest hypoglycemic and cholesterol-lowering effects when compared with non-germinated QY.

A novel WD40-repeat protein involved in formation of epidermal bladder cells in the halophyte quinoa.

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.

Seed characterization and early nitrogen metabolism performance of seedlings from Altiplano and coastal ecotypes of Quinoa.

BACKGROUND: Early seed germination and a functional root system development during establishment are crucial attributes contributing to nutrient competence under marginal nutrient soil conditions. Chenopodium quinoa Willd (Chenopodiaceae) is a rustic crop, able to grow in marginal areas. Altiplano and Coastal/Lowlands are two representative zones of quinoa cultivation in South America with contrasting soil fertility and edaphoclimatic conditions. In the present work, we hypothesize that the ecotypes of Quinoa from Altiplano (landrace Socaire) and from Coastal/Lowland (landrace Faro) have developed differential adaptive responses in order to survive under conditions of low availability of N in their respective climatic zones of Altiplano and Lowlands. In order to understand intrinsic differences for N competence between landraces, seed metabolite profile and germinative capacity were studied. Additionally, in order to elucidate the mechanisms of N uptake and assimilation at limiting N conditions during establishment, germinated seeds of both landraces were grown at either sufficient nitrate (HN) or low nitrate (LN) supply. We studied the photosynthetic performance, protein storage, root morphometrical parameters, activity and expression of N-assimilating enzymes, and the expression of nitrate transporters of roots in plants submitted to the different treatments. RESULTS: Seeds from Socaire landrace presented higher content of free N-related metabolites and faster seed germination rate compared to Faro landrace. Seedlings of both ecotypes presented similar physiological performance at HN supply, but at LN supply their differences were exalted. At LN, Socaire plants showed an increased root biomass (including a higher number and total length of lateral roots), a differential regulation of a nitrate transporter (a NPF6.3-like homologue) belonging to the Low Affinity Transport System (LATS), and an upregulation of a nitrate transporter (a NRT2.1-like homologue) belonging to the High Affinity nitrate Transport System (HATS) compared to Faro. These responses as a whole could be linked to a higher amount of stored proteins in leaves, associated to an enhanced photochemical performance in Altiplano plants, in comparison to Lowland quinoa plants. CONCLUSIONS: These differential characteristics of Socaire over Faro plants could involve an adaptation to enhanced nitrate uptake under the brutal unfavorable climate conditions of Altiplano.

Differentiating, evaluating, and classifying three quinoa ecotypes by washing, cooking and germination treatments, using 1H NMR-based metabolomic approach.

We processed three quinoa ecotypes as they are commonly consumed in a daily diet. For the treatments, quinoa seeds were washed, cooked, and/or germinated. Following treated, we used 1H NMR-based metabolomic profiling to explore differences between the ecotypes. Then, for a non-targeted and targeted food fingerprint analysis of samples, we performed multivariable data analyses, including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and hierarchical cluster analysis. From our study, we were able to discriminate each quinoa ecotype regardless of treatment based on its metabolomic profiling. Additionally, we were able to identify 30 metabolites that were useful to determine the effect of each treatment on nutritional composition. Germination increased the content of most metabolites irrespective of ecotype. In general, ecotype CQE_03 was different from ecotypes CQE_01 and CQE_02. Our phytochemical analysis revealed the effects of washing, cooking, and/or germination, particularly on saponins content.

Bioprospection of native psychrotolerant plant-growth-promoting rhizobacteria from Peruvian Andean Plateau soils associated with Chenopodium quinoa.

The Peruvian Andean Plateau, one of the main production areas of native varieties of Chenopodium quinoa, is exposed to abrupt decreases in environmental temperature, affecting crop production. Plant-growth-promoting rhizobacteria that tolerate low temperatures could be used as organic biofertilizers in this region. We aimed to bioprospect the native psychrotolerant bacteria of the quinoa rhizosphere in this region that show plant-growth-promoting traits. Fifty-one strains belonging to the quinoa rhizosphere were characterised; 73% of the total could grow at low temperatures (4, 6, and 15 °C), whose genetic diversity based on DNA amplification of interspersed repetitive elements (BOX) showed 12 different profiles. According to the 16S rRNA sequence, bacterial species belonging to the classes Beta- and Gammaproteobacteria were identified. Only three (6%) isolates identified as nonpathogenic bacteria exhibited plant-growth-promoting activities, like IAA production, phosphate solubilization, growth in a nitrogen-free medium, and ACC deaminase production at 6 and 15 °C. ILQ215 (Pseudomonas silesiensis) and JUQ307 (Pseudomonas plecoglossicida) strains showed significantly positive plant growth effects in aerial length (about 50%), radicular length (112% and 79%, respectively), and aerial and radicular mass (above 170% and 210%, respectively) of quinoa plants compared with the control without bacteria. These results indicate the potential of both psychrotolerant strains to be used as potential organic biofertilizers for quinoa in this region.

Understanding the role of root-related traits in salinity tolerance of quinoa accessions with contrasting epidermal bladder cell patterning.

MAIN CONCLUSION: To compensate for the lack of capacity for external salt storage in the epidermal bladder cells, quinoa plants employ tissue-tolerance traits, to confer salinity stress tolerance. Our previous studies indicated that sequestration of toxic Na+ and Cl- ions into epidermal bladder cells (EBCs) is an efficient mechanism conferring salinity tolerance in quinoa. However, some halophytes do not develop EBCs but still possess superior salinity tolerance. To elucidate the possible compensation mechanism(s) underlying superior salinity tolerance in the absence of the external salt storage capacity, we have selected four quinoa accessions with contrasting patterns of EBC development. Whole-plant physiological and electrophysiological characteristics were assessed after 2 days and 3 weeks of 400 mM NaCl stress. Both accessions with low EBC volume utilised Na+ exclusion at the root level and could maintain low Na+ concentration in leaves to compensate for the inability to sequester Na+ load in EBC. These conclusions were further confirmed by electrophysiological experiments showing higher Na+ efflux from roots of these varieties (measured by a non-invasive microelectrode MIFE technique) as compared to accessions with high EBC volume. Furthermore, accessions with low EBC volume had significantly higher K+ concentration in their leaves upon long-term salinity exposures compared to plants with high EBC sequestration ability, suggesting that the ability to maintain high K+ content in the leaf mesophyll was as another important compensation mechanism.

Transcriptome profiling identifies transcription factors and key homologs involved in seed dormancy and germination regulation of Chenopodium quinoa.

Chenopodium quinoa, a halophytic crop belonging to the Amaranthaceae, has remarkable resistance to harsh growth conditions and produces seed with excellent nutritional value. This makes it a suitable crop for marginal soils. However, to date most of the commercial cultivars are susceptible to preharvest sprouting (PHS). Meanwhile, understanding of the PHS regulatory mechanisms is still limited. Abscisic acid (ABA) has been demonstrated to be tightly associated with seed dormancy and germination regulation in many crops. Whether ABA metabolism pathway could be manipulated to prevent PHS in quinoa is worth investigating. In the present study, we tested the inhibitory effects of exogenous ABA on quinoa seed germination. By RNA-seq analysis we investigated the global gene expression changes during seed germination, and obtained 1066 ABA-repressed and 392 ABA-induced genes. Cis-elements enrichment analysis indicated that the promoters of these genes were highly enriched in motifs "AAAAAAAA" and "ACGTGKC (K = G/T)", the specific binding motifs of ABI3/VP1 and ABI5. Transcription factor annotation showed that 13 genes in bHLH, MADS-box, G2-like and NF-YB, and five genes in B3, bZIP, GATA and LBD families were specifically ABA-repressed and -induced, respectively. Furthermore, expression levels of 53 key homologs involved in seed dormancy and germination regulation were markedly changed. Hence, we speculated that the 18 transcription factors and the homologs were potential candidates involved in ABA-mediated seed dormancy and germination regulation, which could be manipulated for molecular breeding of quinoa elites with PHS tolerance in future.

In vitro modulation of glucagon-like peptide release by DPP-IV inhibitory polyphenol-polysaccharide conjugates of sprouted quinoa yoghurt.

Glucagon-like peptide-1 (GLP-1) is an important signal in the peripheral and neural systems, which contributes to the maintenance of glucose and energy homeostasis. In this study, 1H NMR validated polyphenols and polysaccharides extracted from sprouted quinoa yoghurt were used as isolates and conjugates to upregulate the stimulation of GLP-1 release in NCI-H716 cells. In addition, we explored their effect on proglucagon and prohormone convertase 3 mRNA expressions, HNF-3γ and CCK-2R gene protein expression, as well as cytosolic calcium release. Variations in concentration showed a dose-dependent GLP-1 stimulation, and were significantly optimized by germination. Proglucagon mRNA expression in NCI-H716 cells was upregulated, and was relatively highest with QYPSP1 treatments in a 2.68 fold. The results suggested that the conjugates had greater potential to stimulate GLP-1 release than their isolates. Sprouted quinoa yoghurt could therefore be a potential functional food useful to regulate glucose and energy homeostasis.

Acid treated biochar enhances cadmium tolerance by restricting its uptake and improving physio-chemical attributes in quinoa (Chenopodium quinoa Willd.).

Heavy metals contamination of soil especially with cadmium (Cd) is a serious environmental concern in the current industrial era. Biochar serves as an excellent ameliorating agent depending upon its properties and application rates. In the pot scale study, effect of acid treated (AWSB) and untreated wheat straw biochar (WSB) was studied on physiology, grain yield, Cd accumulation, and tolerance of quinoa with possible health risks. Different levels of Cd (0, 25, 50 and 75 mg kg-1), AWSB and WSB (1% and 2% (w/w)) were applied in soil. Accumulation of Cd in control plant tissues led to oxidative stress which was shown in terms of increased lipid peroxidation. While biochar application relieved the oxidative damage as confirmed by the low production of H2O2 and TBARS contents. Application of AWSB improved plant growth, pigment contents and gas exchange attributes by limiting the accumulation of Cd in root, shoot and grain of quinoa. Results revealed a significant improvement in the activity of superoxide (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) with biochar at elevated levels of Cd in soil. Target Hazard Quotient (THQ) remained < 1 in the quinoa grains with WSB and AWSB under Cd stress. These results revealed that AWSB most effectively alleviated Cd toxicity in quinoa thereby decreasing Cd accumulation and regulation of Cd induced oxidative stress triggered by the antioxidant enzymatic system.