Elevated CO2 and Nitrogen Supply Boost N Use Efficiency and Wheat (T. aestivum cv. Yunmai) Growth and Differentiate Soil Microbial Communities Related to Ammonia Oxidization.

Elevated CO2 levels (eCO2) pose challenges to wheat (Triticum aestivum L.) growth, potentially leading to a decline in quality and productivity. This study addresses the effects of two ambient CO2 concentrations (aCO2, daytime/nighttime = 410/450 ± 30 ppm and eCO2, 550/600 ± 30 ppm) and two nitrogen (N) supplements (without N supply-N0 and with 100 mg N supply as urea per kg soil-N100) on wheat (T. aestivum cv. Yunmai) growth, N accumulation, and soil microbial communities related to ammonia oxidization. The data showed that the N supply effectively mitigated the negative impacts of eCO2 on wheat growth by reducing intercellular CO2 concentrations while enhancing photosynthesis parameters. Notably, the N supply significantly increased N concentrations in wheat tissues and biomass production, thereby boosting N accumulation in seeds, shoots, and roots. eCO2 increased the agronomic efficiency of applied N (AEN) and the physiological efficiency of applied N (PEN) under N supply. Plant tissue N concentrations and accumulations are positively related to plant biomass production and soil NO3--N. Additionally, the N supply increased the richness and evenness of the soil microbial community, particularly Nitrososphaeraceae, Nitrosospira, and Nitrosomonas, which responded differently to N availability under both aCO2 and eCO2. These results underscore the importance and complexity of optimizing N supply and eCO2 for enhancing crop tissue N accumulation and yield production as well as activating nitrification-related microbial activities for soil inorganic N availability under future global environment change scenarios.

Effects of Heat Stress during Anthesis and Grain Filling Stages on Some Physiological and Agronomic Traits in Diverse Wheat Genotypes.

Heat stress represents a significant environmental challenge that adversely impacts the growth, physiology, and productivity of wheat. In order to determine the response to high temperatures of the wheat varieties developed mostly in the Pannonian environmental zone, as well as varietal differences, we subjected seven varieties from Serbia, one from Australia, and one from the UK to thermal stress during anthesis and mid-grain filling and combined stress during both of these periods. The changes in chlorophyll fluorescence and index, leaf temperature, and main agronomic traits of nine winter wheat varieties were investigated under high temperatures. Heat stress negatively affected leaf temperature, chlorophyll fluorescence, and the chlorophyll index during different growth stages. Compared to the control, stress at anthesis, mid-grain filling, and combined stress resulted in yield reductions of 32%, 46%, and 59%, respectively. Single treatment at anthesis had a more severe effect on the number of grains per plant, causing a 38% reduction compared to the control. Moreover, single treatment during mid-grain filling resulted in the greatest decline in grain weight, with a 29% reduction compared to the control. There was a significant varietal variation in heat tolerance, highlighting Avangarda and NS 40s as the most tolerant varieties that should be included in regular breeding programs as valuable sources of heat tolerance. Understanding the genetic and physiological mechanisms of heat tolerance in these promising varieties should be the primary focus of future research and help develop targeted breeding strategies and agronomic practices to mitigate the adverse effects of heat stress on wheat production.

Reproductive resilience of growth and nitrogen uptake underpins yield improvement in winter wheat with forced delay of sowing.

Winter wheat production is influenced by climate extremes worldwide. Heavy precipitation induced delay of sowing generates limited photothermal resources for wheat early growth. However, how wheat build resilience from stunted seedling growth has not been fully explored. Here, a twelve-year farmers' survey of wheat yield was recorded and four-year field experiments of wheat grown in normal and late-sowing were performed under zero nitrogen (N0) and optimum nitrogen (Opt.N) supply. Wheat growth and N uptake were measured at both vegetative and reproductive stages alongside photothermal resource-use efficiency. Farmers' survey showed 10.4 % yield losses due to delayed sowing compared to the normal. However, four-year field trials revealed that the combination of increasing seeding rates and Opt.N application recovered grain yield of sowing-delayed wheat and even increased by 13.2 % compared to plants in the normal seasons. Although delayed sowing substantially suppressed seedling growth and tillering before winter dormancy, the Opt.N application increased spring tillers by 2.4-fold which were productive at maturity. Further, plant growth and N uptake from jointing to anthesis of sowing-delayed wheat were accelerated by Opt.N, but not by N0 treatment. Delayed sowing significantly shortened the duration of lag phase of grain filling by 3.5 days and by 183 growing degree days compared with the normal, which initiated the linear and fast filling earlier. Increased leaf photosynthesis by 27.4 % during grain filling further supported the fast recovery of grain filling in the sowing-delayed wheat. Concomitantly, the physiological N-use efficiency increased by 46.7 % during grain filling and by 41.5 % at maturity by enhancing N availability and seeding rates, and photothermal resource-use efficiency increased by 1.3- to 1.7-fold for wheat with delayed vs. normal sowing. Overall, these findings highlight the integrated management of nutrient and cultivation to mitigate the impacts of climate extremes on crop productivity through building plant reproductive resilience.

Molecular Investigations to Improve Fusarium Head Blight Resistance in Wheat: An Update Focusing on Multi-Omics Approaches.

Fusarium head blight (FHB) is mainly caused by Fusarium graminearum (Fg) and is a very widespread disease throughout the world, leading to severe damage to wheat with losses in both grain yield and quality. FHB also leads to mycotoxin contamination in the infected grains, being toxic to humans and animals. In spite of the continuous advancements to elucidate more and more aspects of FHB host resistance, to date, our knowledge about the molecular mechanisms underlying wheat defense response to this pathogen is not comprehensive, most likely due to the complex wheat-Fg interaction. Recently, due to climate changes, such as high temperature and heavy rainfall, FHB has become more frequent and severe worldwide, making it even more urgent to completely understand wheat defense mechanisms. In this review, after a brief description of the first wheat immune response to Fg, we discuss, for each FHB resistance type, from Type I to Type V resistances, the main molecular mechanisms involved, the major quantitative trait loci (QTLs) and candidate genes found. The focus is on multi-omics research helping discover crucial molecular pathways for each resistance type. Finally, according to the emerging examined studies and results, a wheat response model to Fg attack, showing the major interactions in the different FHB resistance types, is proposed. The aim is to establish a useful reference point for the researchers in the field interested to adopt an interdisciplinary omics approach.

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.

Ozone priming enhanced low temperature tolerance of wheat (Triticum aestivum L.) based on physiological, biochemical and transcriptional analyses.

Low temperature significantly inhibits the plant growth in wheat (Triticum aestivum L.), prompting the exploration of effective strategies to mitigate low temperature stress. Several priming methods enhance low temperature stress tolerant, however, the role of ozone priming remains unclear in wheat. Here we found ozone priming alleviated low temperature stress in wheat. Transcriptome analysis showed that ozone priming positively modulated 'photosynthesis-antenna proteins' pathway in wheat under low temperature. Which was confirmed by the results of the ozone-primed plants had higher trapped energy flux and electron transport flux per reaction, and less damage to chloroplasts than non-primed plants under low temperature. Ozone priming also mitigated the overstimulation of glutathione metabolism and induced the accumulation of total ascorbic acid and glutathione, maintained redox homeostasis in wheat under low temperature. Moreover, gene expressions and enzyme activities in glycolysis pathways were upregulated in ozone priming comparing with non-priming after the low temperature stress. Furthermore, exogenous antibiotics significantly increased low temperature tolerance, which further proved that the inhibition of ribosome biogenesis by ozone priming was involved in low temperature tolerance in wheat. In conclusion, ozone priming enhanced wheat low temperature tolerance through promoting light-harvesting capacity, redox homeostasis, and carbohydrate metabolism, as well as inhibiting ribosome biogenesis.

TaRLK2.4, a transgressive expression receptor like kinase, improves powdery mildew resistance in wheat.

Plants form two immune systems, pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI), to combat Blumeria graminis f. sp. tritici (Bgt) infection during the evolutionary process. In PTI, receptor-like kinases (RLKs) play important roles during pathogen infections. Based on our previous reports, there were 280 TaRLKs identified in early response to powdery mildew infection, which were divided into 34 subfamilies in this study. Differences in gene structures, cis-acting elements, and expression levels implied the function diversity of TaRLKs. TaRLK2.4, a member of LRK10L-RLKs subfamily, contained 665 amino acids, and located on the cell membrane. The main objective of this study was to investigate the role of the receptor-like kinase gene TaRLK2.4 in conferring powdery mildew resistance in wheat. Real-time quantitative PCR results indicated that TaRLK2.4 expressed during Bgt infection process, and exhibited a transgressive expression characteristic in disease resistance NILs (BJ-1). To elucidate the function of TaRLK2.4 during Bgt infection, the comprehensive analysis of virus induced gene silence and over-expression demonstrated that TaRLK2.4 promoted powdery mildew resistance positively. In summary, these results contribute to a deeper understanding of the complex and diverse biological functions of RLKs, and provide new genetic resources for wheat molecular breeding.

A GC-MS Metabolic Study on Lipophilic Compounds in the Leaves of Common Wheat Triticum aestivum L.

Common wheat (Triticum aestivum L.) is one of the most valuable cereal crops worldwide. This study examined leaf extracts of 30 accessions of T. aestivum and its subspecies using 48 h maceration with methanol by GC-MS and GCxGC-MS. The plants were grown from seeds of the wheat genetics collection of the Wheat Genetics Sector of the Institute of Cytology and Genetics, SB RAS. The analysis revealed 263 components of epicuticular waxes, including linear and branched alkanes, aliphatic alcohols, aldehydes, ketones, ß-diketones, carboxylic acids and their derivatives, mono- and diterpenes, phytosterols, and tocopherols. Hierarchical cluster analysis and principal component analysis were used to identify and visualize the differences between the leaf extracts of different wheat cultivars. Three clusters were identified, with the leading components being (1) octacosan-1-ol, (2) esters of saturated and unsaturated alcohols, and (3) fatty acid alkylamides, which were found for the first time in plant extracts. The results highlight the importance of metabolic studies in understanding the adaptive mechanisms and increasing wheat resistance to stress factors. These are crucial for breeding new-generation cultivars with improved traits.

Induced genetic diversity through mutagenesis in wheat gene pool and significant use of SCoT markers to underpin key agronomic traits.

BACKGROUND: This research explores the efficacy of mutagenesis, specifically using sodium azide (SA) and hydrazine hydrate (HZ) treatments, to introduce genetic diversity and enhance traits in three wheat (Triticum aestivum L.) genotypes. The experiment entails subjecting the seeds to different doses of SA and HZ and cultivating them in the field for two consecutive generations: M1 (first generation) and M2 (second generation). We then employed selective breeding techniques with Start Codon Targeted (SCoT) markers to select traits within the wheat gene pool. Also, the correlation between SCoT markers and specific agronomic traits provides insights into the genetic mechanisms underlying mutagenesis-induced changes in wheat. RESULTS: In the study, eleven genotypes were derived from parent varieties Sids1, Sids12, and Giza 168, and eight mutant genotypes were selected from the M1 generation and further cultivated to establish the M2 generation. The results revealed that various morphological and agronomical characteristics, such as plant height, spikes per plant, spike length, spikelet per spike, grains per spikelet, and 100-grain weight, showed increases in different genotypes from M1 to M2. SCoT markers were employed to assess genetic diversity among the eleven genotypes. The bioinformatics analysis identified a correlation between SCoT markers and the transcription factors ABSCISIC ACID INSENSITIVE3 (ABI3) and VIVIPAROUS1 (VP1), crucial for plant development, growth, and stress adaptation. A comprehensive examination of genetic distance and the function identification of gene-associated SCoT markers may provide valuable insights into the mechanisms by which SA and HZ act as mutagens, enhancing wheat agronomic qualities. CONCLUSIONS: This study demonstrates the effective use of SA and HZ treatments to induce gene diversity through mutagenesis in the wheat gene pool, resulting in the enhancement of agronomic traits, as revealed by SCoT markers. The significant improvements in morphological and agronomical characteristics highlight the potential of mutagenesis techniques for crop improvement. These findings offer valuable information for breeders to develop effective breeding programs to enhance wheat quality and resilience through increased genetic diversity.

Molecular cytogenetic characteristics of new spring bread wheat introgressive lines resistant to stem rust.

Anticipatory wheat breeding for pathogen resistance is key to preventing economically significant crop losses caused by diseases. Recently, the harmfulness of a dangerous wheat disease, stem rust, caused by Puccinia graminis f. sp. tritici, was increased in the main grain-producing regions of the Russian Federation. At the same time, importation of the Ug99 race (TTKSK) is still a possibility. In this regard, the transfer of effective resistance genes from related species to the bread wheat breeding material followed by the chromosomal localization of the introgressions and a marker analysis to identify known resistance genes is of great importance. In this work, a comprehensive analysis of ten spring bread wheat introgressive lines of the Federal Center of Agricultural Research of the South-East Region (L657, L664, L758, L935, L960, L968, L971, L995/1, L997 and L1110) was carried out. These lines were obtained with the participation of Triticum dicoccum, T. timopheevii, T. kiharae, Aegilops speltoides, Agropyron elongatum and Secale cereale. In this study, the lines were evaluated for resistance to the Ug99 race (TTKSK) in the Njoro, Kenya. Evaluation of introgression lines in the field for resistance to the Ug99 race (TTKSK) showed that four lines were immune, two were resistant, three were moderately resistant, and one had an intermediate type of response to infection. By cytogenetic analysis of these lines using fluorescent (FISH) and genomic (GISH) in situ hybridization, introgressions from Ae. speltoides (line L664), T. timopheevii (lines L758, L971, L995/1, L997 and L1110), Thinopyrum ponticum = Ag. elongatum (2n = 70) (L664, L758, L960, L971, L997 and L1110), as well as introgressions from T. dicoccum (L657 and L664), T. kiharae (L960) and S. cereale (L935 and L968) were detected. Molecular markers recommended for marker-oriented breeding were used to identify known resistance genes (Sr2, Sr25, Sr32, Sr1A.1R, Sr36, Sr38, Sr39 and Sr47). The Sr36 and Sr25 genes were observed in lines L997 and L1110, while line L664 had the Sr39+Sr47+Sr25 gene combination. In lines L935 and L968 with 3R(3D) substitution from S. cereale, gene resistance was presumably identified as SrSatu. Thus, highly resistant to both local populations of P. graminis and the Ug99 race, bread wheat lines are promising donors for the production of new varieties resistant to stem rust.

Disomic chromosome 3R(3B) substitution causes a complex of meiotic abnormalities in bread wheat Triticum aestivum L.

Triticum aestivum L. lines introgressed with alien chromosomes create a new genetic background that changes the gene expression of both wheat and donor chromosomes. The genes involved in meiosis regulation are localized on wheat chromosome 3B. The purpose of the present study was to investigate the effect of wheat chromosome 3B substituted with homoeologous rye chromosome 3R on meiosis regulation in disomically substituted wheat line 3R(3B). Employing immunostaining with antibodies against microtubule protein, α-tubulin, and the centromere-specific histone (CENH3), as well as FISH, we analyzed microtubule cytoskeleton dynamics and wheat and rye 3R chromosomes behavior in 3R(3B) (Triticum aestivum L. variety Saratovskaya 29 × Secale cereale L. variety Onokhoiskaya) meiosis. The results revealed a set of abnormalities in the microtubule dynamics and chromosome behavior in both first and second divisions. A feature of metaphase I in 3R(3B) was a decrease in the chiasmata number compared with variety Saratovskaya 29, 34.9 ± 0.62 and 41.92 ± 0.38, respectively. Rye homologs 3R in 13.18 % of meiocytes did not form bivalents. Chromosomes were characterized by varying degrees of compaction; 53.33 ± 14.62 cells lacked a metaphase plate. Disturbances were found in microtubule nucleation at the bivalent kinetochores and in their convergence at the spindle division poles. An important feature of meiosis was the asynchronous chromosome behavior in the second division and dyads at the telophase II in 8-13 % of meiocytes, depending on the anther studied. Considering the 3R(3B) meiotic phenotype, chromosome 3B contains the genes involved in the regulation of meiotic division, and substituting 3B3B chromosomes with rye 3R3R does not compensate for their absence.

Basidiomycetes Polysaccharides Regulate Growth and Antioxidant Defense System in Wheat.

Higher-fungi xylotrophic basidiomycetes are known to be the reservoirs of bioactive metabolites. Currently, a great deal of attention has been paid to the exploitation of mycelial fungi products as an innovative alternative in crop protection. No data exist on the mechanisms behind the interaction between xylotrophic mushrooms' glycopolymeric substances and plants. In this study, the effects of basidiomycete metabolites on the morphophysiological and biochemical variables of wheat plants have been explored. Wheat (Triticum aestivum L. cv. Saratovskaya 29) seedlings were treated with extracellular polysaccharides (EPSs) isolated from the submerged cultures of twenty basidiomycete strains assigned to 13 species and 8 genera. The EPS solutions at final concentrations of 15, 40, and 80 mg/L were applied to wheat seedlings followed by their growth for 10 days. In the plant samples, the biomass, length of coleoptile, shoot and root, root number, rate of lipid peroxidation by malondialdehyde concentration, content of hydrogen peroxide, and total phenols were measured. The peroxidase and superoxide dismutase activity were defined. Most of the EPS preparations improved biomass yields, as well as the morphological parameters examined. EPS application enhanced the activities of antioxidant enzymes and decreased oxidative damage to lipids. Judging by its overall effect on the growth indices and redox system of wheat plants, an EPS concentration of 40 mg/L has been shown to be the most beneficial compared to other concentrations. This study proves that novel bioformulations based on mushroom EPSs can be developed and are effective for wheat growth and antioxidative response. Phytostimulating properties found for EPSs give grounds to consider extracellular metabolites produced in the xylotrophic basidiomycete cultures as an active component capable of inducing plant responses to stress.

Exogenous Sodium Nitroprusside Affects the Redox System of Wheat Roots Differentially Regulating the Activity of Antioxidant Enzymes under Short-Time Osmotic Stress.

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5-24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/-NO), respectively, were used in this work at a concentration of 2 × 10-4 M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O2•-), hydrogen peroxide (H2O2), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/-NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/-NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure.

Genetic diversity and population structure of wheat landraces in Southern Winter Wheat Region of China.

BACKGROUND: Wheat landraces are considered a valuable source of genetic diversity for breeding programs. It is useful to evaluate the genetic diversity in breeding studies such as marker-assisted selection (MAS), genome-wide association studies (GWAS), and genomic selection. In addition, constructing a core germplasm set that represents the genetic diversity of the entire variety set is of great significance for the efficient conservation and utilization of wheat landrace germplasms. RESULTS: To understand the genetic diversity in wheat landrace, 2,023 accessions in the Jiangsu Provincial Crop Germplasm Resource Bank were used to explore the molecular diversity and population structure using the Illumina 15 K single nucleotide polymorphism (SNP) chip. These accessions were divided into five subpopulations based on population structure, principal coordinate and kinship analysis. A significant variation was found within and among the subpopulations based on the molecular variance analysis (AMOVA). Subpopulation 3 showed more genetic variability based on the different allelic patterns (Na, Ne and I). The M strategy as implemented in MStratv 4.1 software was used to construct the representative core collection. A core collection with a total of 311 accessions (15.37%) was selected from the entire landrace germplasm based on genotype and 12 different phenotypic traits. Compared to the initial landrace collections, the core collection displayed higher gene diversity (0.31) and polymorphism information content (PIC) (0.25), and represented almost all phenotypic variation. CONCLUSIONS: A core collection comprising 311 accessions containing 100% of the genetic variation in the initial population was developed. This collection provides a germplasm base for effective management, conservation, and utilization of the variation in the original set.

Transcription factor TaNF-YB2 interacts with partners TaNF-YA7/YC7 and transcriptionally activates distinct stress-defensive genes to modulate drought tolerance in T. Aestivum.

BACKGROUND: Drought stress limits significantly the crop productivity. However, plants have evolved various strategies to cope with the drought conditions by adopting complex molecular, biochemical, and physiological mechanisms. Members of the nuclear factor Y (NF-Y) transcription factor (TF) family constitute one of the largest TF classes and are involved in plant responses to abiotic stresses. RESULTS: TaNF-YB2, a NY-YB subfamily gene in T. aestivum, was characterized in this study focusing on its role in mediating plant adaptation to drought stress. Yeast two-hybrid (Y-2 H), biomolecular fluoresence complementation (BiFC), and Co-immunoprecipitation (Co-IP) assays indicated that TaNF-YB2 interacts with the NF-YA member TaNF-YA7 and NF-YC family member TaNF-YC7, which constitutes a heterotrimer TaNF-YB2/TaNF-YA7/TaNF-YC7. The TaNF-YB2 transcripts are induced in roots and aerial tissues upon drought signaling; GUS histochemical staining analysis demonstrated the roles of cis-regulatory elements ABRE and MYB situated in TaNF-YB2 promoter to contribute to target gene response to drought. Transgene analysis on TaNF-YB2 confirmed its functions in regulating drought adaptation via modulating stomata movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis. TaNF-YB2 possessed the abilities in transcriptionally activating TaP5CS2, the P5CS family gene involving proline biosynthesis and TaSOD1, TaCAT5, and TaPOD5, the genes encoding antioxidant enzymes. Positive correlations were found between yield and the TaNF-YB2 transcripts in a core panel constituting 45 wheat cultivars under drought condition, in which two types of major haplotypes including TaNF-YB2-Hap1 and -Hap2 were included, with the former conferring more TaNF-YB2 transcripts and stronger plant drought tolerance. CONCLUSIONS: TaNF-YB2 is transcriptional response to drought stress. It is an essential regulator in mediating plant drought adaptation by modulating the physiological processes associated with stomatal movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis, depending on its role in transcriptionally regulating stress response genes. Our research deepens the understanding of plant drought stress underlying NF-Y TF family and provides gene resource in efforts for molecular breeding the drought-tolerant cultivars in T. aestivum.

Physiological and genomic insights into a psychrotrophic drought-tolerant bacterial consortium for crop improvement in cold, semiarid regions.

The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions.

Comprehensive identification, characterization and expression analysis of genes underpinning heat acclimatization in Triticum durum and Aegilops tauschii.

Wheat (Triticum aestivum L.) is an important cereal crop cultivated and consumed worldwide. Global warming-induced escalation of temperature during the seedling and grain-filling phase adversely affects productivity. To survive under elevated temperatures, most crop plants develop natural mechanisms at molecular level by activating heat shock proteins. However, other heat stress-related proteins like heat acclimatization (HA) proteins are documented in hexaploid wheat but have not been explored in detail in its diploid and tetraploid progenitors, which might help to overcome elevated temperature regimes for short periods. Our study aims to explore the potential HA genes in progenitors Triticum durum and Aegilops tauschii that perform well at higher temperatures. Seven genes were identified and phylogenetically classified into three families: K homology (KH), Chloroplast protein-enhancing stress tolerance (CEST), and heat-stress-associated 32 kDa (HSA32). Protein-protein interaction network revealed partner proteins that aid mRNA translation, protein refolding, and reactive species detoxification. Syntenic analysis displayed highly conserved relationships. RT-qPCR-based expression profiling revealed HA genes to exhibit diverse and dynamic patterns under high-temperature regimes, suggesting their critical role in providing tolerance to heat stress. The present study furnishes genetic landscape of HA genes that might help in developing climate-resilient wheat with higher acclimatization potential.

Root Hairs: An under-explored target for sustainable cereal crop production.

To meet the demands of a rising human population, plant breeders will need to develop improved crop varieties that maximize yield in the face of increasing pressure on crop production. Historically, the optimization of crop root architecture has represented a challenging breeding target due to the inaccessibility of the root systems. Root hairs, single cell projections from the root epidermis, are perhaps the most overlooked component of root architecture traits. Root hairs play a central role in facilitating water, nutrient uptake, and soil cohesion. Current root hair architectures may be suboptimal under future agricultural production regimes, coupled with an increasingly variable climate. Here, we review the genetic control of root hair development in the world's three most important crops: rice, maize and wheat, and highlight conservation of gene function between monocots and the model dicot species Arabidopsis. Advances in genomic techniques including Gene-Editing combined with traditional plant breeding methods have the potential to overcome many inherent issues associated with the design of improved root hair architectures. Ultimately, this will enable detailed characterization of the effects of contrasting root hair morphology strategies on crop yield and resilience, and the development of new varieties better adapted to deliver future food security.

Analysis of the Effects of the Vrn-1 and Ppd-1 Alleles on Adaptive and Agronomic Traits in Common Wheat (Triticum aestivum L.).

Wheat heading time is primarily governed by two loci: VRN-1 (response to vernalization) and PPD-1 (response to photoperiod). Five sets of near-isogenic lines (NILs) were studied with the aim of investigating the effect of the aforementioned genes on wheat vegetative period duration and 14 yield-related traits. Every NIL was sown in the hydroponic greenhouse of the Institute of Cytology and Genetics, SB RAS. To assess their allelic composition at the VRN-1 and PPD-1 loci, molecular markers were used. It was shown that HT in plants with the Vrn-A1vrn-B1vrn-D1 genotype was reduced by 29 and 21 days (p < 0.001) in comparison to HT in plants with the vrn-A1Vrn-B1vrn-D1 and the vrn-A1vrn-B1Vrn-D1 genotypes, respectively. In our study, we noticed a decrease in spike length as well as spikelet number per spike parameter for some NIL carriers of the Vrn-A1a allele in comparison to carriers of the Vrn-B1 allele. PCA revealed three first principal components (PC), together explaining more than 70% of the data variance. Among the studied genetic traits, the Vrn-A1a and Ppd-D1a alleles showed significant correlations with PCs. Regarding genetic components, significant correlations were calculated between PC3 and Ppd-B1a (-0.26, p < 0.05) and Vrn-B1 (0.57, p < 0.05) alleles. Thus, the presence of the Vrn-A1a allele affects heading time, while Ppd-D1a is associated with plant height reduction.

Contribution of Antioxidant System Components to the Long-Term Physiological and Protective Effect of Salicylic Acid on Wheat under Salinity Conditions.

Salicylic acid (SA) plays a crucial role in regulating plant growth and development and mitigating the negative effects of various stresses, including salinity. In this study, the effect of 50 µM SA on the physiological and biochemical parameters of wheat plants under normal and stress conditions was investigated. The results showed that on the 28th day of the growing season, SA pretreatment continued to stimulate the growth of wheat plants. This was evident through an increase in shoot length and leaf area, with the regulation of leaf blade width playing a significant role in this effect. Additionally, SA improved photosynthesis by increasing the content of chlorophyll a (Chl a) and carotenoids (Car), resulting in an increased TAP (total amount of pigments) index in the leaves. Furthermore, SA treatment led to a balanced increase in the levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) in the leaves, accompanied by a slight but significant accumulation of ascorbic acid (ASA), hydrogen peroxide (H2O2), proline, and the activation of glutathione reductase (GR) and ascorbate peroxidase (APX). Exposure to salt stress for 28 days resulted in a reduction in length and leaf area, photosynthetic pigments, and GSH and ASA content in wheat leaves. It also led to the accumulation of H2O2 and proline and significant activation of GR and APX. However, SA pretreatment exhibited a long-term growth-stimulating and protective effect under stress conditions. It significantly mitigated the negative impacts of salinity on leaf area, photosynthetic pigments, proline accumulation, lipid peroxidation, and H2O2. Furthermore, SA reduced the salinity-induced depletion of GSH and ASA levels, which was associated with the modulation of GR and APX activities. In small-scale field experiments conducted under natural growing conditions, pre-sowing seed treatment with 50 µM SA improved the main indicators of grain yield and increased the content of essential amino acids in wheat grains. Thus, SA pretreatment can be considered an effective approach for providing prolonged protection to wheat plants under salinity and improving grain yield and quality.