Phytochemical, Morphological, and Physiological Variation in Different Ajowan (Trachyspermum ammi L.) Populations as Affected by Salt Stress, Genotype × Year Interaction and Pollination System.

In the present research, 28 populations of ajowan (Trachyspermum ammi L.) were evaluated for agro-morphological traits and essential oil yield in two consecutive years. Then, selected ajowan populations from these two years were used for further morphophysiological and biochemical studies under different salinity levels (control, 60, 90, and 120 mM NaCl). The main components of the oil were thymol (32.7-54.29%), γ-terpinene (21.71-32.81%), and p-cymene (18.74-26.16%). Salt stress caused an increase in essential oil content in the Esfahfo and Qazvin populations. The highest total phenolic and flavonoid contents were found in the Arak population grown in 60 mM NaCl (183.83 mg TAE g-1 DW) and the Yazd population grown in 90 mM NaCl (5.94 mg QE g-1 DW). Moreover, the Yazd population exhibited the strongest antioxidant activity based on DPPH (IC50 = 1566 µg/mL) under 60 mM NaCl and the highest reducing power (0.69 nm) under 120 mM NaCl. The results revealed that low and moderate salt stress improves the phytochemicals of ajowan seeds, which are useful for pharmaceutical and food applications. In this research, some morphological traits, as well as essential oil yield, were evaluated in open pollinated versus self-pollinated plants. As a result, plant height, number of flowering branches, and crown diameter significantly decreased in some populations, while a significant increase was obtained for number of flowers per umbel and seed numbers per umbel. Finally, self-pollination of ajowan might provide new insights for further breeding programs to increase oil or thymol content in ajowan.

Overexpression of Choline Oxidase Gene in Three Filial Generations of Rice Transgenic Lines.

Background: Glycinebetaine (GB) accumulation in many halophytic plants, animals, and microorganisms confers abiotic stress tolerance to salinity, drought, and extreme temperatures. Although there are a few genetic and biochemical pathways to synthesize GB, but isolation of a single gene Choline Oxidase (codA) from Arthrobacter spp. have opened a new hatch to engineer the susceptible plants. Objectives: The effects of overexpressed codA gene, through multiple copy insertion and GB accumulation on salinity tolerance in rice were studied. Materials and Methods: Seed-derived embryogenic calli of 'Tarom Molaie' cultivar were targeted with two plasmids pChlCOD and pCytCOD both harboring the codA gene using the biolistic mediated transformation. The regenerated T0 plants were screened by PCR analysis. A line containing three copies of codA gene and harboring pChlCOD and pCytCOD was identified by Southern blot analysis. The expression of codA gene in this transgenic line was then confirmed by RT-PCR. The Mendelian segregation pattern of the inserted sequences was accomplished by the progeny test using PCR. The effects of overexpression of codA on salinity tolerance were evaluated at germination and seedling stage using T2-pChl transgenic line and control seeds in the presence of 0, 100, 200, and 300 mM NaCl. Finally, leaf growth dynamics of T2-pChlCOD transgenic line and control line under hydroponic conditions in the presence of 0, 40, 80, and 120 mM NaCl were assessed. Results: The seed germination experiment results showed that the transformed seeds had a higher germination rate than the controls under all salinity treatments. But also, the leaf growth dynamics showed that the control plants had a more favorable leaf growth dynamic in all of the treatments. Although, the transgenic lines (T0, T1 and T2) exhibited lower performance than the wild type, the transgenic line varied for GB and choline contents and increasing codA gene copy number led to increased GB content. Conclusion: In a salinity sensitive crop such as rice, GB may not significantly contribute to the plant protection against salt stress. Also, insufficiency of choline resources as GB precursor might have affected the overall growth ability of the transgenic line and resulted in decreased leaf growth dynamics.

Changes in Essential Oil Composition, Polyphenolic Compounds and Antioxidant Capacity of Ajowan (Trachyspermum ammi L.) Populations in Response to Water Deficit.

Ajowan (Trachyspermum ammi L.) is considered a valuable spice plant with a high thymol content. Seed yield, essential oil constituents, polyphenolic composition, and antioxidant capacity of ajowan (Trachyspermum ammi L.) populations were evaluated in three (normal, moderate, and severe) water irrigation regimes. The highest essential oil content (5.55%) was obtained under normal condition in the Yazd population. However, both essential oil and seed yield showed significant reductions as a result of water stress. According to gas chromatography-mass spectrometry (GC-MS) analysis, thymol (61.44%), γ-terpinene (26.96%), and p-cymene (20.32%) were identified as the major components of the oil. The highest (89.01%) and the lowest (37.54%) thymol contents were in Farsmar and Hamadan populations in severe stress condition, respectively. Based on HPLC analysis, chlorogenic (3.75-47.35 mg/100 g), caffeic (13.2-40.10 mg/100 g), and ferulic acid (11.25-40.10 mg/100 g) were identified as the major phenolic acids, while rutin was determined as the major flavonoid (11.741-20.123 mg/100 g). Moreover, total phenolic and flavonoid contents were elevated under drought stress treatment, while antioxidants responded inconsistently to stress based on two model systems. Overall, the Yazd population exhibited a superior response to water stress, as evidenced by its less reduced thymol and oil yield content, while Arak and Khormo had the highest accumulation of polyphenolic compounds.

Grain and flour quality of wheat genotypes grown under heat stress.

Heat stress during the grain-filling period is the main abiotic stress factor limiting grain yield and quality in wheat (Triticum aestivum L.). In this study, 64 wheat genotypes were exposed to heat stress during reproduction caused by delayed sowing in two growing seasons. Grain yield, 1000 grain weight (GW), grain hardness (GH), and grain-quality related traits were investigated. Heat stress caused a significant decrease in GW through reducing starch content (SC) and a non-compensating rise in protein content (PC), and thereby resulted in lower yield. In addition, significant increases in flour water absorption (WA), Zeleny sedimentation volume (ZT), ash content (AC), lipid content (LC), loaf volume (LV), wet gluten content (WG), dry gluten content (DG), gluten index (GI), and amylopectin content (APC) were found following heat stress. In contrast, decreases in grain moisture content (MC) and amylose content (AMC) induced by heat stress were observed. The heat-tolerant genotypes were superior in grain yield, GW, SC, AMC, and MC. While the sensitive genotypes contained higher PC, LV, GI and AMP. A group of wheat genotypes characterized with a higher yield, AMC, GW, and SC as well as lower PC, WA, GH, ZT, and LV; and was found to be the most heat tolerant by principal component analysis. Lighter weight and smaller grains produce a smaller starchy endosperm with lower quality (less amylose) and higher grain protein content in heat stress compared to normal conditions. Heat stress caused by delayed sowing improves some of the baking-quality related traits.

Do ancient wheats contain less gluten than modern bread wheat, in favour of better health?

Popular media messaging has led to increased public perception that gluten-containing foods are bad for health. In parallel, 'ancient grains' have been promoted with claims that they contain less gluten. There appears to be no clear definition of 'ancient grains' but the term usually includes einkorn, emmer, spelt and Khorasan wheat. Gluten is present in all wheat grains and all can induce coeliac disease (CD) in genetically susceptible individuals. Analyses of 'ancient' and 'modern' wheats show that the protein content of modern bread wheat (Triticum aestivum) has decreased over time while the starch content increased. In addition, it was shown that, compared to bread wheat, ancient wheats contain more protein and gluten and greater contents of many CD-active epitopes. Consequently, no single wheat type can be recommended as better for reducing the risks of or mitigating the severity of CD. An estimated 10% of the population of Western countries suffers from gastrointestinal symptoms that lack a clear organic cause and is often referred to as irritable bowel syndrome (IBS). Many of these patients consider themselves gluten sensitive, but in most cases this is not confirmed when tested in a medical setting. Instead, it may be caused by gas formation due to fermentation of fructans present in wheat or, in some patients, effects of non-gluten proteins. A significant overlap of symptoms with those of CD, IBS and inflammatory bowel disease makes a medical diagnosis a priority. This critical narrative review examines the suggestion that 'ancient' wheat types are preferred for health and better tolerance.

Physiological and Transcriptome Indicators of Salt Tolerance in Wild and Cultivated Barley.

Barley is used as a model cereal to decipher salt tolerance mechanisms due to its simpler genome than wheat and enhanced salt tolerance compared to rice and wheat. In the present study, RNA-Seq based transcriptomic profiles were compared between salt-tolerant wild (Hordeum spontaneum, genotype no. 395) genotype and salt-sensitive cultivated (H. vulgare, 'Mona' cultivar) subjected to salt stress (300 mM NaCl) and control (0 mM NaCl) conditions. Plant growth and physiological attributes were also evaluated in a separate experiment as a comparison. Wild barley was significantly less impacted by salt stress than cultivated barley in growth and physiology and hence was more stress-responsive functionally. A total of 6,048 differentially expressed genes (DEGs) including 3,025 up-regulated and 3,023 down-regulated DEGs were detected in the wild genotype in salt stress conditions. The transcripts of salt-stress-related genes were profoundly lower in the salt-sensitive than the tolerant barley having a total of 2,610 DEGs (580 up- and 2,030 down-regulated). GO enrichment analysis showed that the DEGs were mainly enriched in biological processes associated with stress defenses (e.g., cellular component, signaling network, ion transporter, regulatory proteins, reactive oxygen species (ROS) scavenging, hormone biosynthesis, osmotic homeostasis). Comparison of the candidate genes in the two genotypes showed that the tolerant genotype contains higher functional and effective salt-tolerance related genes with a higher level of transcripts than the sensitive one. In conclusion, the tolerant genotype consistently exhibited better tolerance to salt stress in physiological and functional attributes than did the sensitive one. These differences provide a comprehensive understanding of the evolved salt-tolerance mechanism in wild barley. The shared mechanisms between these two sub-species revealed at each functional level will provide more reliable insights into the basic mechanisms of salt tolerance in barley species.

Genetic analysis of salinity tolerance in wheat (Triticum aestivum L.).

Understanding the genetics of salt tolerance is of utmost need to combat the rising prevalence of soil salinity through employing tolerant cultivars. The current study was carried out to investigate the quantitative genetic basis of agronomical and physiological-related traits of salinity-stressed plants using seven generations (parental cultivars, F1, F2, F3, BC1, and BC2) of wheat grown in the field under normal and saline conditions. The combined analysis of variance showed highly significant effects of salinity and genotypes (generations) on all the traits. The scaling tests did not support the three-parameter model (additive-dominance model); hence, the six-parameter model was used to assess the genetic effects governing the traits in this study. The epistatic gene effects were crucial, as were additive and dominance gene effects for plant height, K/Na, and yield in salinity stress conditions. The highest heritability was observed for total chlorophyll, carotenoid, SPAD chlorophyll, and K/Na ratio in saline conditions. The additive genetic variance was more important than the dominance variance for grain weight, K, K/Na in salinity conditions. The findings of the current study may have important implications in the quantitative genetics of salinity tolerance and the development of cultivars tolerant to salinity in wheat.

Relationships between grain, flour, and dough quality characteristics and solvent retention capacity tests of twelve triticale cultivars and parental species.

Relationships amongst solvent retention capacity (SRC) profiles and quality characteristics of triticale cultivars were investigated. Superior triticale grains resulted into flours with preferable quality attributes for baking bread. Standard and supplementary SRC-values exhibited significant correlation with grain, flour, and dough quality. Positive correlations among sucrose-SRC with ash, pentosan, and ferulic acid (FA) contents were significant. The standard SRC-profiles along with metabisulfite-SRC (MBS-SRC) and ethanol-SRC exhibited significant correlation with damaged starch (DS) content. The ethanol-SRC demonstrated strong correlations with water absorption capacity, FA, and Dmax-value alveolab parameter. Triticale flours containing a higher amount of anti-parallel ß-sheets and tyrosine exhibited higher lactic acid-SRC (LA-SRC) and gluten-performance-index (GPI). Positive correlations between sodium dodecylsulphate-SRC (SDS-SRC) and anti-parallel ß-sheets percentages were noticed. The LA-SRC, GPI, MBS-SRC, SDS-SRC, and SDS+MBS-SRC were positively correlated with SDS-sedimentation, gluten index and negatively to sulfhydryl-groups content. Triticales having higher LA-SRC and MBS-SRC resulted in dough with higher strength and tenacity.

Polyphenols, Flavonoids, and Antioxidant Activity Involved in Salt Tolerance in Wheat, Aegilops cylindrica and Their Amphidiploids.

Aegilops spp. is the closest genus to wheat (Triticum spp.), which makes Aegilops great candidates to exhibit precursors of wheat features. Aegilops cylindrica Host displays excellent salt tolerance. In the current study, biochemical and phytochemical compounds in the leaves of two wheat cultivars, one hyper-salt tolerant Ae. cylindrica genotype and their amphidiploids (derived from "Chinese Spring" × Ae. cilindrica and "Roshan" × Ae. cylindrica), grown under control and saline field conditions, were assessed. These compounds included total protein content, proline content, electrolyte leakage, total flavonoid content, total phenolic content, DPPH radical scavenging activity, and reducing power. In addition, phenolic components were also identified using HPLC analysis. Chlorogenic acid, ellagic acid, ferulic acid, syringic acid, vanillic acid, p-coumaric acid, caffeic acid, and gallic acid were the most abundant phenolic acids. Luteolin, apigenin, and rutin were the most abundant flavonoids in the leaves. Salt stress significantly increased all biochemical variables, with the exceptions of reducing power and p-coumaric acid. Interestingly, amphidiploid genotypes exhibited intermediate levels of most of the detected phenolic compounds between the two parental species. As demonstrated by bivariate correlations luteolin, chlorogenic acid, caffeic acid and apigenin could predict inhibition percentage by DPPH assay, suggesting a possible role in the cellular defense against oxidative stress in wheat. The amphidiploids and their wild parent performed significantly better than wheat cultivars on phenolic constituents, flavonoids, and maintaining redox homeostasis under salt stress conditions.

Variation in bioactive compounds, antioxidant and antibacterial activity of Iranian Chrysanthemum morifolium cultivars and determination of major polyphenolic compounds based on HPLC analysis.

In this study, chemical profiling, phenolic and flavonoid contents, as well as the antibacterial and antioxidant activity of 17 Iranian Chrysanthemum morifolium cultivars were evaluated. The high performance liquid chromatography analysis revealed the presence of eight compounds with the major constituents including chlorogenic acid (0-934.7 mg/100 g), ferulic acid (12.7-171.6 mg/100 g), rutin (0-225.8 mg/100 g) and luteolin (2.83-213.5 mg/100 g). The cultivar "Ashna" with 63.6 mg tannic acid equivalents g-1 DW had the highest amount of total phenol, while the highest flavonoid content (13.52 mg quercetin equivalents g-1DW) was observed in cultivar "Shokoh". The antioxidant activities of the samples were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the reducing power assay. The results showed that the cultivars "Poya3" (IC50 = 385.7) and "Dorna2" (IC50 = 489.4) possessed a higher antioxidant activity than the others in DPPH model system. Antimicrobial activity was also evaluated based on minimal inhibitory concentration (MIC) and minimal bactericidal concentration values. MIC values were in the range of 5-10 mg ml-1 against Salmonella enterica and Bacillus cereus and 10-20 mg ml-1 against Staphylococcus aureus and Escherichia coli. Finally, Chrysanthemum cultivars with high bioactive compounds were introduced for beneficial usage in food and industrial applications.

Variation in Phytochemical, Morphological, and Ploidy Levels of Iranian Thymus Species.

Thymus is one of the most important genera of the Lamiaceae family. This work was performed to assess inter and intra species variation, which is an indispensable prerequisite for the selection and the exploitation of the germplasm, using yield, secondary metabolites, and ploidy level criteria. Nineteen Iranian populations belonging to 11 Thymus species which includes T. vulgaris were used in this study. The results of cytological observations on the 19 populations revealed the three root-tip chromosome numbers of 2n=2x=30, 2n=4x=56 or 60 (diploid and tetraploid). This study also presents the results of a two-year field experiment that evaluates the agronomic and morphology of the 19 populations of Thymus spp. Cluster analysis grouped the populations into six groups and explained the relationships among ploidy levels, morphological traits, and essential oils (EOs). In general, diploid species belonged to the thymol chemotype, whilst carvacrol chemotype consistently dependent on the gene-dosage effect. Thymus migricus, T. daenensis-2, T. serpyllum, and T. trautvetteri populations with diverse thymol background were the best selection as the parents to improve thymol in a breeding program. Moreover, dry and fresh weight criteria can be used to improve EO content in thyme. Achieving this goal would be expected by crossing T. migricus and T. daenensis-2. Finally, providing relevant information on the ploidy level of Thymus species, with emphasis on morphology and EO components variations, may be recommended for the selection of populations or species to improve bioactive components as well as morphological traits in future breeding programs.

Sequencing and variation of terpene synthase gene (TPS2) as the major gene in biosynthesis of thymol in different Thymus species.

Thyme (Thymus spp.) is a valuable genus of Lamiaceae family with different pharmaceutical and food properties. Thymol has also been considered as the major essential oil compound in most of the studied Thymus species. In this research, the gene encoding γ-terpinene synthase (Ttps2) was sequenced in T. vulgaris and in eight Iranian thymes including T. carmanicus, T. daenensis, T. fedtschenkoi, T. kotschyanus, T. migricus, T. pubescens, T. serpyllum, and T. trautvetteri. Genetic relationships based on terpene synthase genes were also determined among the studied species. Rapid Amplification of cDNA Ends (RACE) PCR was done to complete the sequence of all species. The cDNA of the studied species possessed an open reading frame ranging from 1788 to 1794 bp that encode for a protein of 596-598 amino acids, presenting all the conserved motifs characteristics of monoterpene synthases. The taxonomic status of Thymus species was determined based on eight reported sections. The species were classified in three major groups. The first and second group comprised species of Micantes and Mastichina sections. The third cluster included the species belonging to Serpyllum and Pseudothymbra sections. Overall, phylogenetic analysis according to whole sequence of Ttps2 gene can help providing insights in respect to its evolutionary process. Finally, clustering based on the amount of main essential oils components (thymol and carvacrol) was compared with that based on Ttps2 gene classification in the studied Thymus species, showing that clustering is not always in accordance.

Thymol, carvacrol, and antioxidant accumulation in Thymus species in response to different light spectra emitted by light-emitting diodes.

The essential oils and antioxidant activity of four Thymus species were evaluated under five light spectra (namely, red, blue, red-blue, white, and greenhouse condition). The highest essential oil yield (4.17%) was observed under red light in T. migricus, while the lowest (1.05%) was observed in T. carmanicus under greenhouse conditions. Light quality also led to difference in essential oil constituents. The highest thymol (66%) was found in T. migricus exposed to blue light, while the least (1.69%) was observed in T. kotschyanus grown under red-blue light. The LED treatments did not induce any significant effect on carvacrol of Thymus species in comparison to the greenhouse condition. Finally, the analysis of variance indicates that the effect of light varied with the studied species. T. migricus performed the highest antioxidant capacity (IC50 = 176.8 µg/mL) under blue light. Overall, essential oil components as well as antioxidants showed significant responses to light emitting diodes wavelengths.

Imaging Salt Uptake Dynamics in Plants Using PET.

Soil salinity is a global environmental challenge for crop production. Understanding the uptake and transport properties of salt in plants is crucial to evaluate their potential for growth in high salinity soils and as a basis for engineering varieties with increased salt tolerance. Positron emission tomography (PET), traditionally used in medical and animal imaging applications for assessing and quantifying the dynamic bio-distribution of molecular species, has the potential to provide useful measurements of salt transport dynamics in an intact plant. Here we report on the feasibility of studying the dynamic transport of 22Na in millet using PET. Twenty-four green foxtail (Setaria viridis L. Beauv.) plants, 12 of each of two different accessions, were incubated in a growth solution containing 22Na+ ions and imaged at 5 time points over a 2-week period using a high-resolution small animal PET scanner. The reconstructed PET images showed clear evidence of sodium transport throughout the whole plant over time. Quantitative region-of-interest analysis of the PET data confirmed a strong correlation between total 22Na activity in the plants and time. Our results showed consistent salt transport dynamics within plants of the same variety and important differences between the accessions. These differences were corroborated by independent measurement of Na+ content and expression of the NHX transcript, a gene implicated in sodium transport. Our results demonstrate that PET can be used to quantitatively evaluate the transport of sodium in plants over time and, potentially, to discern differing salt-tolerance properties between plant varieties. In this paper, we also address the practical radiation safety aspects of working with 22Na in the context of plant imaging and describe a robust pipeline for handling and incubating plants. We conclude that PET is a promising and practical candidate technology to complement more traditional salt analysis methods and provide insights into systems-level salt transport mechanisms in intact plants.

Inheritance of fruit yield and quality in melon (Cucumis melo L.) grown under field salinity stress.

Cultivation of salinity-tolerant crops can help mitigate salinization threats to soil and fresh water resources. This study was conducted to investigate the quantitative genetic basis of yield, yield components, and quality-related traits of salinity-stressed melon (Cucumis melo L.) using 55 melon hybrids and their 11 parents (half diallel). The results of combined ANOVA revealed highly significant effects of salinity and genotype on all the traits studied. Salinity stress influenced the inheritance of all the traits. The lower values of variance components (mainly additive), GCA/SCA ratio, as well as broad- and narrow-sense heritabilities were estimated for saline conditions (ECW = 14 dSm-1) when compared with those obtained under non-saline conditions. Fruit weight was governed by additive effects in non-saline conditions, but largely governed by the dominant nature in saline conditions. Based on the results obtained, especially as reflected by fruit yield, it is possible to develop melon hybrids with higher salinity tolerance than is currently observed in tolerant cultivars. On the other hand, most of the traits contributing to fruit quality are found to be governed by additive effects, allowing for their further improvement through recurrent selection to develop new cultivars of high yield and good quality for cultivation under saline conditions.

Expression pattern of salt tolerance-related genes in Aegilops cylindrica.

Aegilops cylindrica, a salt-tolerant gene pool of wheat, is a useful plant model for understanding mechanism of salt tolerance. A salt-tolerant USL26 and a salt-sensitive K44 genotypes of A. cylindrica, originating from Uremia Salt Lake shores in Northwest Iran and a non-saline Kurdestan province in West Iran, respectively, were identified based on screening evaluation and used for this work. The objective of the current study was to investigate the expression patterns of four genes related to ion homeostasis in this species. Under treatment of 400 mM NaCl, USL26 showed significantly higher root and shoot dry matter levels and K+ concentrations, together with lower Na+ concentrations than K44 genotype. A. cylindrica HKT1;5 (AecHKT1;5), SOS1 (AecSOS1), NHX1 (AecNHX1) and VP1 (AecVP1) were partially sequenced to design each gene specific primer. Quantitative real-time PCR showed a differential expression pattern of these genes between the two genotypes and between the root and shoot tissues. Expressions of AecHKT1;5 and AecSOS1 was greater in the roots than in the shoots of USL26 while AecNHX1 and AecVP1 were equally expressed in both tissues of USL26 and K44. The higher transcripts of AecHKT1;5 in the roots versus the shoots could explain both the lower Na+ in the shoots and the much lower Na+ and higher K+ concentrations in the roots/shoots of USL26 compared to K44. Therefore, the involvement of AecHKT1;5 in shoot-to-root handover of Na+ in possible combination with the exclusion of excessive Na+ from the root in the salt-tolerant genotype are suggested.

Essential oil composition, total phenolic, flavonoid contents, and antioxidant activity of Thymus species collected from different regions of Iran.

In this study, the essential oil (EO) composition, flavonoid and phenolic contents, and antioxidant activities of fourteen Thymus accessions belonging to ten species were evaluated. Gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of 38 compounds with the major constituents including thymol (12.4-79.74%), carvacrol (4.37-42.14%), geraniol (0.3-22.44%), and p-cymene (0.8-12.86%). Cluster analysis identified three groups of high thymol, geraniol/linalool, and high carvacrol. The highest phenolic and flavonoid contents were detected in T. daenensis-1 (70.6mg tannic acid equivalents (TAE) g-1 DW) and T. vulgaris (8.55mg quercetin equivalents (QE) g-1 DW), respectively. The antioxidant activities of the samples were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and reducing power assay. The results demonstrated that T. daenensis-3 (IC50=273.36), T. vulgaris (IC50=289.3), and T. fedtschenkoi-3 (IC50=339.22) possessed higher antioxidant activities than the others. Finally, the Thymus species with high bioactive compounds may be recommended for further food applications.

Cultivated Ancient Wheats (Triticum spp.): A Potential Source of Health-Beneficial Food Products.

A sustainable and wholesome food supply is the most important incentive that has led to an increasing interest in ancient wheats over the past few decades. Domestication of wheat, followed by breeding efforts, largely over the past 2 centuries, has resulted in yield increases but with grain quality deterioration due to the reduction of protein, vitamins, and minerals in grains. It has also resulted in a decrease in food diversity due to the loss of genetic variation in the cultivated wheat gene pool. Ancient hulled wheats, einkorn, emmer, and spelt are among the early cereals that were domesticated in their places of origin in the Fertile Crescent of the Middle East where their wild predecessors still grow. The ancient wheats had a long history as part of human diet, and played an important role as a major source of food for the early civilizations in that region. The risks of genetic erosion of crop plants and the associated likely consequences for agriculture now call for revitalization of the unrealized potentials of ancestral species like einkorn, emmer, and spelt wheat, the domesticated ancestors of modern durum and bread wheats. These ancestors need to be exploited to maximize the sustainable supply of grain protein, fiber, minerals, and phytochemicals. In addition, ancient wheat biodiversity can be utilized to ensure sustainable wheat production in the context of climate change and low-input organic farming systems. This review provides a holistic synthesis of the information on ancient wheats to facilitate a greater exploitation of their potential benefits.

Effects of abiotic stress on physiological plasticity and water use of Setaria viridis (L.).

The emerging model Setaria viridis with its C4 photosynthesis and adaptation to hot and dry locations is a promising system to investigate water use and abiotic stress tolerance. We investigated the physiological plasticity of six S. viridis natural accessions that originated from different regions of the world under normal conditions and conditions of water-deficit stress and high temperatures. Accessions Zha-1, A10.1 and Ula-1 showed significantly higher leaf water potential (Ψleaf), photosynthesis (A), transpiration (E), and stomatal conductance (gs) rates compared to Ast-1, Aba-1 and Sha-1 when grown under stress conditions. Expression analysis of genes associated with C4 photosynthesis, aquaporins, ABA biosynthesis and signaling including genes involved in stress revealed an increased sensitivity of Ast-1, Aba-1 and Sha-1 to stresses. Correlation analysis of gene expression data with physiological and biochemical changes characterized A10.1 and Ast-1 as two extreme tolerant and sensitive accessions originated from United States and Azerbaijan under water-deficit and heat stress, respectively. Although preliminary, our study demonstrated the plasticity of S. viridis accessions under stress, and allows the identification of tolerant and sensitive accessions that could be use to study the mechanisms associated with stress tolerance and to characterize of the regulatory networks involved in C4 grasses.