Triticum Aestivum Research Articles

Karyotypic and phenotypic condensation in allotetraploid wheats accompanied with reproductive strategy transformation: from natural evolution to domestication.

Allotetraploid wheat reflects evolutionary divergence and domestication convergence in the karyotypic and phenotypic evolution, accompanied with the transformation from r- strategy to K- strategy in reproductive fitness. Allotetraploid wheat, the progenitor of hexaploidy bread wheat, has undergone 300,000years of natural evolution and 10,000years of domestication. The variations in karyotype and phenotype as well as fertility fitness have not been systematically linked. Here, by combining fluorescent in situ hybridization with the quantification of phenotypic and reproductive traits, we compared the karyotype, vegetative growth phenotype and reproductive fitness among synthesized, wild and domesticated accessions of allotetraploid wheat. We detected that the wild accessions showed dramatically high frequencies of homologous recombination and copy number variations of simple sequence repeats (SSR) comparing with synthetic and domesticated accessions. The phenotypic traits reflected significant differences among the populations shaped by distinct evolutionary processes. The diversity observed in wild accessions was significantly greater than that in domesticated ones, particularly in traits associated with vegetative growth and spike morphology. We found that the active pollen of domesticated accessions exhibited greater potential of germination, despite a lower rate of active pollen compared with the wild accessions, indicating a transformation in reproductive fitness strategy for pollen development in domesticated accessions compared to the wild accessions, from r-strategy to K-strategy. Our results demonstrate the condensation of karyotype and phenotype from natural wild accessions to domesticated accessions in allotetraploid wheats. Ecological strategy transformation should be seriously considered from evolution to domestication in polyploid plants, especially crops, which may provide a perspective on the adaptive evolution of polyploid plants.

Functional Characterization of Accessible Chromatin in Common Wheat.

Eukaryotic gene transcription is fine-tuned by precise spatiotemporal interactions between cis-regulatory elements (CREs) and trans-acting factors. However, how CREs individually or coordinated with epigenetic marks function in regulating homoeolog bias expression is still largely unknown in wheat. In this study, through comprehensively characterizing open chromatin coupled with DNA methylation in the seedling and spikelet of common wheat, we observed that differential chromatin openness occurred between the seedling and spikelet, which plays important roles in tissue development through regulating the expression of related genes or through the transcription factor (TF)-centered regulatory network. Moreover, we found that CHH methylation may act as a key determinant affecting the differential binding of TFs, thereby resulting in differential expression of target genes. In addition, we found that sequence variations in MNase hypersensitive sites (MHSs) result in the differential expression of key genes responsible for important agronomic traits. Thus, our study provides new insights into the roles of CREs in regulating tissue or homoeolog bias expression, and controlling important agronomic traits in common wheat. It also provides potential CREs for genetic and epigenetic manipulation toward improving desirable traits for wheat molecule breeding.

Identification and development of functional markers for purple grain genes in durum wheat (Triticum durum Desf.).

Two allelic variants of Pp-A3 and Pp-B1 were identified in purple durum wheat. Molecular markers at both loci were developed and validated on an independent panel, offering a breakthrough for wheat improvement. Purple wheats are a class of cereals with pigmented kernels of particular interest for their antioxidant and anti-inflammatory properties. Although two complementary loci (Pp-B1 and Pp-A3), responsible for purple pericarp have been pinpointed in bread wheat (Triticum aestivum L.), in durum wheat (Triticum durum Desf.) the causative genes along with functional and non-functional alleles are still unknown. Here, using a quantitative trait loci (QTL) mapping approach on a RIL population derived from purple and non-purple durum wheat genotypes, we identified three major regions on chromosomes 2A, 3A, and 7B explaining the highest phenotypic variation (> 50%). Taking advantage of the Svevo genome, a MYB was reannotated on chromosome 7B and reported as a candidate for Pp-B1. An insertion of ~ 1.6kb within the first exon led to a non-functional allele (TdPpm1b), whereas the functional allele (TdPpm1a) was characterized and released for the first time in durum wheat. Pp-A3 was instead identified as a duplicated gene, of which only one was functional. The promoter sequencing of the functional allele (TdPpb1a) revealed six 261-bp tandem repeats in purple durum wheat, whereas one unit (TdPpb1b) was found in the yellow once. Functional molecular markers at both loci were developed to precisely discriminate purple and not purple genotypes, representing a valuable resource for selecting superior purple durum lines at early growth stages. Overall, our results expand the understanding of the function of MYB and bHLH activators in durum wheat, paving new ways to explore cis-regulatory elements at the promoter level.

Temporal dynamics of N-hydroxypipecolic acid and salicylic acid pathways in the disease response to powdery mildew in wheat

Wheat (Triticum aestivum) is a major staple crop worldwide, and its yields are significantly threatened by wheat powdery mildew (Blumeria graminis f. sp. tritici). Enhancing disease resistance in wheat is crucial for meeting global food demand. This study investigated the disease response in wheat, focusing on the bioactive small molecules salicylic acid (SA), pipecolic acid (Pip), and N-hydroxypipecolic acid (NHP), to provide new insights for molecular breeding. We found that endogenous levels of SA, Pip, and NHP significantly increased in infected plants, with Pip and NHP levels rising earlier than those of SA. Notably, the rate of increase of NHP was substantially higher than that of SA. The gene expression levels of SARD1 and CBP60g, which are transcription factors for SA, Pip, and NHP biosynthesis, increased significantly during the early stages of infection. We also found that during the later stages of infection, the expression of ALD1, SARD4, and FMO1, which encode enzymes for Pip and NHP biosynthesis, dramatically increased. Additionally, ICS1, which encodes a key enzyme involved in SA biosynthesis, also showed increased expression during the later stages of infection. The temporal changes in ICS1 transcription closely mirrored the behavior of endogenous SA levels, suggesting that the ICS pathway is the primary route for SA biosynthesis in wheat. In conclusion, our results suggest that the early accumulation of Pip and NHP cooperates with SA in the disease response against wheat powdery mildew infection.

Analysis and profiling of the purple acid phosphatase gene family in wheat (Triticum aestivum L.).

Purple acid phosphatases (PAPs) play a vital role in plant phosphorus nutrition, serving as a crucial family of metallo-phosphoesterase enzymes. This research aimed to identify the PAP genes from the A/B/D genomes of Triticum aestivum to elucidate evolutionary mechanisms of the gene family in plants and provide genomic information for subsequent research on phosphorous-use efficiency in wheat crops. In total, 105 PAP genes (TaPAPs) were identified from the A/B/D genomes by using the Arabidopsis thaliana and Oryza sativa PAP protein sequences as queries for BLASTP against the wheat protein database. The TaPAPs were grouped into six subfamilies, Ia (17), Ib (26), IIa (11), IIb (30), IIIa (12), and IIIb (9), based on their similarities in the structure of genes and the presence of conserved protein motifs. A majority of TaPAPs were derived from tandemly (20) or segmentally (87) duplicated, with the homoeologous chromosomes 5A/B/D harboring the most duplicated PAP genes. Further analysis indicated that TaPAPs were responsible for the modulation of seed, root, and leaf development and hormone synthesis and signaling, as well as plant responses to abiotic stresses, including low temperatures, drought, and anaerobic conditions. Nine TaPAPs (TaPAP9-4A/4B/4D, TaPAP24-6A/6B/6D, and TaPAP28-7A/7B/7D) were constitutively expressed in diverse tissues such as root, shoot, leaf, spike, and seed, while the remaining genes exhibited tissue-specific expression patterns. Concerning the response to phosphate (Pi) deprivation, 57 TaPAPs were highly expressed in roots under Pi stress, including TaPAP31-4A, 4B, and 4D homeologs from the subfamily IIIb. A TaPAP31-4A transgene in A. thaliana promoted plant growth and development while increasing plant resistance to Pi-deficiency stress by enhancing the secretion of phosphatase. These discoveries provide a scientific foundation for comprehending the role of TaPAPs, offering valuable insights for identifying additional candidate genes and fostering the development of new wheat varieties with enhanced tolerance to low phosphorus conditions.

Regulating Leaf Photosynthesis and Soil Microorganisms through Controlled-Release Nitrogen Fertilizer Can Effectively Alleviate the Stress of Elevated Ambient Ozone on Winter Wheat.

The mitigation mechanisms of a kind of controlled-release nitrogen fertilizer (sulfur-coated controlled-release nitrogen fertilizer, SCNF) in response to O3 stress on a winter wheat (Triticum aestivum L.) variety (Nongmai-88) were studied in crop physiology and soil biology through the ozone-free-air controlled enrichment (O3-FACE) simulation platform and soil microbial metagenomics. The results showed that SCNF could not delay the O3-induced leaf senescence of winter wheat but could enhance the leaf size and photosynthetic function of flag leaves, increase the accumulation of nutrient elements, and lay the foundation for yield by regulating the release rate of nitrogen (N). By regulating the soil environment, SCNF could maintain the diversity and stability of soil bacterial and archaeal communities, but there was no obvious interaction with the soil fungal community. By alleviating the inhibition effects of O3 on N-cycling-related genes (ko00910) of soil microorganisms, SCNF improved the activities of related enzymes and might have great potential in improving soil N retention. The results demonstrated the ability of SCNF to improve leaf photosynthetic function and increase crop yield under O3-polluted conditions in the farmland ecosystem, which may become an effective nitrogen fertilizer management measure to cope with the elevated ambient O3 and achieve sustainable production.

Long-term straw return increases fungal residual contribution to soil microaggregate nitrogen pool: An eco-enzymatic stoichiometric study

Straw return is a widespread agricultural practice for improving cropland nitrogen (N) stocks. However, the contribution of microbial N to the soil aggregate N pool and the underlying microbial metabolic regulation mechanisms remain uncertain. This study was based on a 13-year field experiment with rice (Oryza sativa L.) and wheat (Triticum aestivum L.) rotation, using only a chemical fertilizer alone (CF) as the control. We analyzed the effects of the chemical fertilizer combined with (CS, 9500 kg ha−1 y−1) and wheat (4000 kg ha−1 y−1) straw on microbial derived-N, microbial carbon (C) and N limitations. We also assessed microbial N use efficiency (NUE) in various aggregates of ferric lixisols (0–20 cm). Rotary tillage reached a depth of 20 cm. The CS significantly increased microbial-derived N concentrations in soil aggregates and enhanced the contribution of fungal residual N to the N pool in aggregates < 0.25 mm, but did not affect those > 0.25 mm. Conversely, the bacterial contribution to the N pool was not affected by CS. Meanwhile, CS significantly increased the soil organic C and microbial biomass in the aggregates. The results of our eco-enzymatic stoichiometric model revealed that the CS significantly alleviated microbial C limitations and increased microbial NUE in soil aggregates. Structural equation modeling further revealed that the microbial biomass and soil organic C contents are key drivers of the microbial C limitation. The increased contribution of fungal residual N to the N pools in < aggregates 0.25 mm was attributed to improved microbial NUE resulting from the straw, without altering net N mineralization rates or β-1,4-N-acetylglucosidase activity. Our findings suggest that straw return promotes microbial-derived N production and sequestration by alleviating microbial C limitation. The strategies governing these microbial-derived N responses in aggregates to straw return might vary. This might be valuable for designing cropland management practices to improve N storage.

Genome-wide characterization and expression analysis of the CINNAMYL ALCOHOL DEHYDROGENASE gene family in Triticum aestivum.

CINNAMYL ALCOHOL DEHYDROGENASE (CAD) catalyzes the NADPH-dependent reduction of cinnamaldehydes into cinnamyl alcohols and is a key enzyme found at the final step of the monolignol pathway. Cinnamyl alcohols and their conjugates are subsequently polymerized in the secondary cell wall to form lignin. CAD genes are typically encoded by multi-gene families and thus traditionally organized into general classifications of functional relevance. In silico analysis of the hexaploid Triticum aestivum genome revealed 47 high confidence TaCAD copies, of which three were determined to be the most significant isoforms (class I) considered bone fide CADs. Class I CADs were expressed throughout development both in RNAseq data sets as well as via qRT-PCR analysis. Of the 37 class II TaCADs identified, two groups were observed to be significantly co-expressed with class I TaCADs in developing tissue and under chitin elicitation in RNAseq data sets. These co-expressed class II TaCADs were also found to be phylogenetically unrelated to a separate clade of class II TaCADs previously reported to be an influential resistance factor to pathogenic fungal infection. Lastly, two groups were phylogenetically identified as class III TaCADs, which possess distinct conserved gene structures. However, the lack of data supporting their catalytic activity for cinnamaldehydes and their bereft transcriptional presence in lignifying tissues challenges their designation and function as CADs. Taken together, our comprehensive transcriptomic analyses suggest that TaCAD genes contribute to overlapping but nonredundant functions during T. aestivum growth and development across a wide variety of agroecosystems and provide tolerance to various stressors.

Exploring Evolutionary Pathways and Abiotic Stress Responses through Genome-Wide Identification and Analysis of the Alternative Oxidase (AOX) Gene Family in Common Oat (Avena sativa).

The alternative oxidase (AOX), a common terminal oxidase in the electron transfer chain (ETC) of plants, plays a crucial role in stress resilience and plant growth and development. Oat (Avena sativa), an important crop with high nutritional value, has not been comprehensively studied regarding the AsAOX gene family. Therefore, this study explored the responses and potential functions of the AsAOX gene family to various abiotic stresses and their potential evolutionary pathways. Additionally, we conducted a genome-wide analysis to explore the evolutionary conservation and divergence of AOX gene families among three Avena species (Avena sativa, Avena insularis, Avena longiglumis) and four Poaceae species (Avena sativa, Oryza sativa, Triticum aestivum, and Brachypodium distachyon). We identified 12 AsAOX, 9 AiAOX, and 4 AlAOX gene family members. Phylogenetic, motif, domain, gene structure, and selective pressure analyses revealed that most AsAOXs, AiAOXs, and AlAOXs are evolutionarily conserved. We also identified 16 AsAOX segmental duplication pairs, suggesting that segmental duplication may have contributed to the expansion of the AsAOX gene family, potentially preserving these genes through subfunctionalization. Chromosome polyploidization, gene structural variations, and gene fragment recombination likely contributed to the evolution and expansion of the AsAOX gene family as well. Additionally, we hypothesize that AsAOX2 may have potential function in resisting wounding and heat stresses, while AsAOX4 could be specifically involved in mitigating wounding stress. AsAOX11 might contribute to resistance against chromium and waterlogging stresses. AsAOX8 may have potential fuction in mitigating ABA-mediated stress. AsAOX12 and AsAOX5 are most likely to have potential function in mitigating salt and drought stresses, respectively. This study elucidates the potential evolutionary pathways of the AsAOXs gene family, explores their responses and potential functions to various abiotic stresses, identifies potential candidate genes for future functional studies, and facilitates molecular breeding applications in A. sativa.

Adaptive breeding of soft spring wheat for the conditions of Western Siberia and the Omsk region

The article provides the results of testing 13 soft spring wheat variety samples of the Federal State Budgetary Scientific Institution "Omsk ASC" in the competitive variety testing nursery in 2020–2022. According to the ripeness groups, characteristics is given according to phenotypic traits, resistance to leaf diseases and grain quality. Variety samples have been identified based on yield, stability factor (S.F.) and yield range (d), with weaker variability (CV), which exceed standards and are characterized by the highest level of realization of productivity potential. In medium-ripeness group the following variety samples have been selected: Lutescens 83/14-3, Lutescens 205/12-5, in mid-late maturity group – Lutescens 15/16-17, which ensure the formation of a consistently high grain yield, grain quality, and resistance to fungal pathogens, regardless of the environmental conditions. The parameters of ecological plasticity of variety samples according to grain yield were determined and the most adaptive ones in this set were identified – Lutescens 83/14-3 (bi =1.16, Sd2 = 0.02) and Lutescens 205/12-5 (bi = 1.09, Sd2 = 0.03). The obtained research results made it possible to transfer the cultivars ‘Omskaya krepost` 2’ (Lutescens 205/12-5) and ‘Omskaya krepost` 5’ (Lutescens 83/14-3) to the state variety testing. Using the PCR method, a genetic profile of the transferred cultivars was obtained using certain DNA markers.

The Effects of a Cultivar and Production System on the Qualitative and Quantitative Composition of Bioactive Compounds in Spring Wheat (Triticum sp.).

Spelt Triticum aestivum L. subsp. spelta (cv. Wirtas), einkorn Triticum monococcum L. (cv. Samopsza) and emmer Triticum dicoccum Schrank (Schuebl) (cv. Płaskurka biała and Płaskurka ciemna) spring wheat cultivars were analyzed and compared to common wheat Triticum aestivum L. subsp. aestivum (cv. Harenda, Kandela, Mandaryna, Serenada, Goplana, Kamelia, Nimfa, Rusałka, Struna, Zadra) cultivated in an organic production system. Moreover, the performance of four common wheat cultivars (cv. Harenda, Kandela, Mandaryna, Serenada) grown in organic, conventional and integrated production systems were compared. The UHPLC-DAD-MS and TLC-DPPH• analyses of specific substances (phenolic acids and alkylresorcinols) were evaluated to ascertain the potential of spring wheat cultivars for promoting human health and suitability for cultivation in an organic production system. The highest yield was observed for the T. aestivum L. subsp. aestivum (modern hull-less) cv. Nimfa (4.45 t/ha), which also demonstrated the lowest resistance to Fusarium spp. infection. Among the contemporary hull-less cultivars, cv. Mandaryna and cv. Harenda exhibited the highest resistance to this pathogen (2.4% and 3.7% of grains infected by Fusarium, respectively), while simultaneously displaying the highest organic phenolic acid content (900.92 and 984.55 µg/g of the grain) and the highest antioxidant potential. It is noteworthy that the cereal hulls of T. monococcum L. (old hulled) (cv. Samopsza) exhibited a markedly elevated content of phenolic acids (approximately 4000 µg/g of the grain). This may have contributed to the reduced incidence of Fusarium infection (9.3% of grains infected) observed in the grains of this cultivar. Furthermore, the hulls proved to be a rich source of phenolics with high antioxidant activity, which is beneficial for human and animal health.

Increasing germination and antioxidant activity of aged wheat and triticale grains by priming with gamma-aminobutyric acid

During storage, elevated temperature and humidity cause accelerated aging and deterioration of seeds of various plant species, including important cultivated cereals, such as wheat and triticale. Germination of old seeds can be facilitated by seed priming with physiologically active substances that correct the pro/antioxidant balance and reduce the development of oxidative stress. Gamma-aminobutyric acid (GABA) is a regulatory compound with direct and indirect antioxidant effects. However, its effect on the germination of grains of cereals with low germination has not been extensively studied. The objective of this study was to examine the impact of GABA priming on the germination of aged grains of winter bread wheat (Triticum aestivum ‘Scorpion’) and winter triticale (×Triticosecale ‘Raritet’). the extent of oxidative stress and the state of the antioxidant system in seedlings. The results indicated that a three-hour treatment of grains with GABA at the optimal concentration (1 mM) resulted in a significant (18–21%) increase in germination energy and seed germination rate, as well as an increase in the biomass of shoots and roots of seedlings of both species. Concomitantly, the influence of GABA resulted in a reduction in oxidative stress markers, including the generation of superoxide anion radicals, hydrogen peroxide content, and the product of lipid peroxidation malondialdehyde. In wheat seedlings, the total content of phenolic compounds increased, while in triticale seedlings, the content of anthocyanins increased almost twofold. In seedlings derived from GABA-primed grains, catalase activity was also significantly elevated in the absence of notable alterations in superoxide dismutase and peroxidase activity. It was postulated that GABA priming is a promising approach for enhancing the germination of cereal seeds with diminished sowing quality.

Effects of biochar on growth and yield of Wheat (Triticum aestivum L.) under salt stress

Globally from abiotic stresses, salt stress is the major stress that limits crop production. One of them is wheat that has been utilized by more than 1/3 of the world population as staple food due to its nutritive value. Biochar is an activated carbon that can ameliorate the negative impacts on plants under saline conditions. The present study was conducted to examine the ameliorative impact of “Biochar application” to Triticum aestivum L. plant grown under salinity stress and evaluated on the basis of various growth, yield, physiological, biochemical attributes. Preliminary experiment was done to select the Triticum aestivum L. varieties with 90% germination rate for further experiment. The selected varieties, FSD08 and PUNJAB-11 of wheat were treated with two levels of sodium chloride (0 mM and 120 mM). Two varieties of wheat included FSD08 and PUNJAB-11 were treated with two levels of sodium chloride (0 mM and 120 mM). To address the impact of salt stress two levels of biochar 0% and 5% was used as exogenous application. A three way completely randomized experimentation was done in 24 pots of two wheat varieties with three replicates. The results demonstrated that salt stress affected growth, physiological attributes, yield and inorganic mineral ions (Ca2+ and K+) in roots and shoots parameters of wheat negatively while biochar overall improved the performance of plant. SOD, CAT, APX and POD activities enhanced during salt stress as the plant self-defense mechanism against salinity to minimize the damaging effect. Salt stress also significantly increased the membrane permeability, and levels of H2O2, MDA, Cl and Na ions. Biochar treatment nullified negative impacts of NaCl and improved the plant growth and yield significantly. Hence, biochar amendment can be suggested as suitable supplement for sustainable crop production under salinization.

Metabolomics Uncovers the Mechanisms of Nitrogen Response to Anthocyanins Synthesis and Grain Quality of Colored Grain Wheat (Triticum aestivum L.).

Nitrogen (N) is a key factor for plant growth and affects anthocyanin synthesis. This study aimed to clarify the potential mechanisms of N levels (LN, 0 kg·ha-1; MN, 150 kg·ha-1; HN, 225 kg·ha-1) in anthocyanin synthesis and grain quality of colored grain wheat. HN increased the yield component traits and grain morphology traits in colored grain wheat while decreasing the processing and nutrient quality traits. Most quality traits were significantly negatively correlated with the yield composition and morphological traits. Anthocyanin was more accumulated under LN conditions, but other related yield and morphological traits of colored grain wheat declined. The anthocyanin content was the highest in blue wheat, followed by that in purple wheat. Cyanidin-3-O-(6-O-malonyl-β-d-glucoside) and cyanidin-3-O-rutinoside were the predominant anthocyanins in blue and purple wheat. The identified anthocyanin-related metabolites were associated with flavonoid biosynthesis, anthocyanin biosynthesis, and secondary metabolite biosynthesis. Therefore, the study provided information for optimizing nitrogen fertilizer management in producing high quality colored wheat and verified the close relationship between anthocyanin and low N condition.

Biosynthesized Zinc Nanoparticles and their Plant Growth-Promoting Effect on Wheat (Triticum aestivum L.) Cultivation

The zinc nanoparticles were biosynthesized using Pseudomonas and actinobacteria and characterized through UV-Visible spectroscopy, Particle Size Analyzer (PSA), Scanning Electron Microscope (SEM), (EDX), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). After biosynthesis and characterization of the nanoparticles (NPs), a field experiment was conducted to know the effect of biosynthesized zinc nanoparticles on wheat crop. In wheat seed priming at 500 ppm and foliar spraying at 500 ppm at panicle initiation stage with zinc nanoparticles biosynthesized through actinobacteria (T6) increased the plant height (25.75%), number of tillers per meter row length (35.98%), leaf area (25.84%), leaf area index (25.75%), total dry matter production (36.46%), productive spikes per square meter (16.98%), number of grains per spike (27.29%), grain weight per spike (30.71), 1,000 grain weight (10.43%), grain yield (17.58%) and straw yield (14.59%) than seed priming at 500 ppm and foliar spraying at 500 ppm at panicle initiation stage with zinc nanoparticles biosynthesized through Pseudomonas (T3) and commercial zinc nanoparticles (T9). Farmers can replace the conventional zinc source with nano forms to obtain the higher yield and yield attributing characteristics, where biosynthesized nanoparticles could be alternative to chemical nanoparticles in terms of high cost and pollution hazards.

Breeding wheat for organic farming: Can the high grain protein gene Gpc-B1 help to tackle challenges in view of end-use quality?

Organic farming contributes to sustain healthy ecosystems, but challenges such as lower crop yields and supply of the nitrogen needs of crops remain. Wheat is the most important organic arable crop in Europe and grain protein content is the main quality trait also for grading organic wheat despite that high baking quality can be also realized at lower protein contents. Hence, breeding of organic wheat varieties that realize a stable high grain protein content even at lower nitrogen availability is of utmost importance to guarantee income of organic wheat growers. A major QTL for high grain protein content was identified in wild emmer and transferred into bread wheat. We tested six different wheat genetic backgrounds varying for the presence/absence of the functional Gpc-B1 allele in multi-location trials in Central Europe for their performance under organic growing. The increase in grain protein content caused by the functional Gpc-B1 allele was present in almost all genetic backgrounds, however, was not consistent across all tested quality traits. None the less, the functional Gpc-B1 allele may play a major role to increase the stability of organic wheat to reach minimum requirements by traders and processors with respect to grain protein content.

AAC Hassler Canada Western Red Spring wheat

AAC Hassler (PT496) is an early maturing, high yielding, awned and hollow stemmed Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) cultivar suited to growing conditions in the northern Canadian Prairies. AAC Hassler yielded 8% more than Glenn, 6% more than Parata and 6% more than Carberry in the Parkland Wheat Registration Trials (2019-2021). AAC Hassler matured 4 days earlier than Carberry and had similar maturity as Parata. AAC Hassler had similar height to Glenn and the lodging score was similar to Parata. The test weight of AAC Hassler was 2% lower than the mean of the checks and the thousand kernel weight was similar to Glenn. AAC Hassler had protein content 0.1% higher than Carberry. AAC Hassler expressed an intermediate resistant reaction to Fusarium head blight (FHB; Fusarium graminearum Schwabe). AAC Hassler was moderately resistant to the prevalent races of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. &amp; E. Henn) and moderately susceptible to common bunt [Tilletia caries (DC) Tul. &amp; C. Tul.]. It was resistant to prevalent races of leaf rust (Puccinia triticina Erikss.) and stripe rust (Puccinia striiformis Westend). AAC Hassler was susceptible to orange wheat blossom midge (OBWM) (Sitodiplosis mosellana Géhin). AAC Hassler was registered under the CWRS class.

Elucidation of the genetic architecture of water absorption capacity in hard winter wheat through genome wide association study.

Water absorption capacity (WAC) influences various aspects of bread making, such as loaf volume, bread yield, and shelf life. Despite its importance in the baking process and end-product quality, its genetic determinants are less explored. To address this limitation, a genome-wide association study was conducted on 337 hard wheat (Triticum aestivum L.) genotypes evaluated over 5 years in multi-environmental trials. Phenotyping was done using the solvent retention capacity (SRC) test with water (SRC-water), sucrose (SRC-sucrose), lactic acid (SRC-lactic acid), and sodium carbonate (SRC-carbonate) as solvents. Individuals were genotyped using genotyping-by-sequencing to detect single nucleotide polymorphisms across the wheat genome. To detect the genomic regions that underline the SRCs and gluten performance index (GPI), a genome-wide association study was performed using six multi-locus models using the mrMLM package in R. Adjusted means for SRC-water ranged from 54.1% to 66.5%, while SRC-carbonate exhibited a narrow range from 84.9% to 93.9%. Moderate to high genomic heritability values were observed for SRCs and GPI, ranging from h2=0.61 to 0.88. The genome-wide association study identified a total of 42 quantitative trait nucleotides (QTNs), of which five explained over 10% of the phenotypic variation (R2 ≥ 10%). Most of the QTNs were detected on chromosomes 1A, 1B, 3B, and 5B. Few QTNs, such as S1A_5190318, S1B_3282665, S4D_472908721, and S7A_37433960, were located near gliadin, glutenin starch synthesis, and galactosyltransferase genes. Overall, these results show WAC to be under polygenic genetic control, with genes involved in the synthesis of key flour components influencing overall water absorption.

Commonalities and Specificities in Wheat (Triticum aestivum L.) Responses to Aluminum Toxicity and Low Phosphorus Revealed by Transcriptomics and Targeted Metabolomics.

Aluminum (Al) toxicity and low phosphorus availability (LP) are the top two co-existing edaphic constraints limiting agriculture productivity in acid soils. Plants have evolved versatile mechanisms to cope with the two stresses alone or simultaneously. However, the specific and common molecular mechanisms, especially those involving flavonoids and carbohydrate metabolism, remain unclear. Laboratory studies were conducted on two wheat genotypes-Fielder (Al-tolerant and P-efficient) and Ardito (Al-sensitive and P-inefficient)-exposed to 50 μM Al and 2 μM Pi (LP) in hydroponic solutions. After 4 days of stress, wheat roots were analyzed using transcriptomics and targeted metabolomics techniques. In Fielder, a total of 2296 differentially expressed genes (DEGs) were identified under Al stress, with 1535 upregulated and 761 downregulated, and 3029 DEGs were identified under LP stress, with 1591 upregulated and 1438 downregulated. Similarly, 4404 DEGs were identified in Ardito under Al stress, with 3191 upregulated and 1213 downregulated, and 1430 DEGs were identified under LP stress, with 1176 upregulated and 254 downregulated. GO annotation analysis results showed that 4079 DEGs were annotated to the metabolic processes term. These DEGs were significantly enriched in the phenylpropanoid, flavonoid, flavone and flavonol biosynthesis, and carbohydrate metabolism pathways by performing the KEGG enrichment analysis. The targeted metabolome analysis detected 19 flavonoids and 15 carbohydrate components in Fielder and Ardito under Al and LP stresses. In Fielder, more responsive genes and metabolites were involved in flavonoid metabolism under LP than Al stress, whereas the opposite trend was observed in Ardito. In the carbohydrate metabolism pathway, the gene and metabolite expression levels were higher in Fielder than in Ardito. The combined transcriptome and metabolome analysis revealed differences in flavonoid- and carbohydrate-related genes and metabolites between Fielder and Ardito under Al and LP stresses, which may contribute to Fielder's higher resistance to Al and LP. The results of this study lay a foundation for pyramiding genes and breeding multi-resistant varieties.

TaCAMTA4 negatively regulates H2O2-dependent wheat leaf rust resistance by activating catalase 1 expression.

Leaf rust, caused by Puccinia triticina Erikss. (Pt), is a serious disease threatening wheat (Triticum aestivum L.) production worldwide. Hydrogen peroxide (H2O2) triggered by Pt infection in resistant wheat cultivars cause oxidative damage directly to biomolecules or is activated by calcium signaling and mediates the hypersensitive response. Calmodulin-binding transcriptional activator 4 (TaCAMTA4) has been reported to negatively regulate wheat resistance to Pt. In this study, we found that TaCAMTA4 was induced by Pt race 165 in its compatible host harboring the Pt resistant locus Lr26, TcLr26, and silencing of TaCAMTA4 increased local H2O2 accumulation and Pt resistance. Subcellular localization and autoactivation tests revealed that TaCAMTA4 is a nucleus-localized transcriptional activator. Furthermore, four DNA motifs recognized by TaCAMTA4 were identified by transcription factor-centered Y1H. Through analyzing the transcriptome database, four gene clusters were identified, each containing a different DNA motif on each promoter. Among them, the expression of catalase 1 (TaCAT1) with motif-1 was highly induced in the compatible interaction and was decreased when TaCAMTA4 was silenced. The results of EMSA, ChIP-qPCR, and RT-qPCR further showed that TaCAMTA4 directly bound motif-1 in the TaCAT1 promoter. Furthermore, silencing of TaCAT1 resulted in enhanced resistance to Pt and increased local H2O2 accumulation in wheat, which is consistent with that of TaCAMTA4. Since CAMTAs are Ca2+ sensors and catalases catalyze the decomposition of H2O2, we hypothesize that Ca2+ regulates the plant immune networks that are controlled by H2O2 and implicate a potential mechanism for Pt to suppress resistance by inducing the expression of the TaCAMTA4-TaCAT1 module, which consequently enhances H2O2 scavenging and attenuates H2O2-dependent resistance.