Genome-Wide Identification and Expression Profiling of the ABF Transcription Factor Family in Wheat (Triticum aestivum L.).

Members of the abscisic acid (ABA)-responsive element (ABRE) binding factor (ABF) and ABA-responsive element binding protein (AREB) families play essential roles in the regulation of ABA signaling pathway activity and shape the ability of plants to adapt to a range of stressful environmental conditions. To date, however, systematic genome-wide analyses focused on the ABF/AREB gene family in wheat are lacking. Here, we identified 35 ABF/AREB genes in the wheat genome, designated TaABF1-TaABF35 according to their chromosomal distribution. These genes were further classified, based on their phylogenetic relationships, into three groups (A-C), with the TaABF genes in a given group exhibiting similar motifs and similar numbers of introns/exons. Cis-element analyses of the promoter regions upstream of these TaABFs revealed large numbers of ABREs, with the other predominant elements that were identified differing across these three groups. Patterns of TaABF gene expansion were primarily characterized by allopolyploidization and fragment duplication, with purifying selection having played a significant role in the evolution of this gene family. Further expression profiling indicated that the majority of the TaABF genes from groups A and B were highly expressed in various tissues and upregulated following abiotic stress exposure such as drought, low temperature, low nitrogen, etc., while some of the TaABF genes in group C were specifically expressed in grain tissues. Regulatory network analyses revealed that four of the group A TaABFs (TaABF2, TaABF7, TaABF13, and TaABF19) were centrally located in protein-protein interaction networks, with 13 of these TaABF genes being regulated by 11 known miRNAs, which play important roles in abiotic stress resistance such as drought and salt stress. The two primary upstream transcription factor types found to regulate TaABF gene expression were BBR/BPC and ERF, which have previously been reported to be important in the context of plant abiotic stress responses. Together, these results offer insight into the role that the ABF/AREB genes play in the responses of wheat to abiotic stressors, providing a robust foundation for future functional studies of these genes.

The Evaluation of a Long-Term Experiment on the Relationships between Weather, Nitrogen Fertilization, Preceding Crop, and Winter Wheat Grain Yield on Cambisol.

In this paper, a sequence (1979-2022) of a long-term trial established in Lukavec in 1956 (Czech Republic) focusing on the effect of weather, various nitrogen (N) fertilization methods (control, PK, N1PK, N2PK, and N3PK) and preceding crops (cereals, legumes, and oil plants) on winter wheat grain yield is presented. The weather significantly changed at the site of the long-term trial. While the trend in the mean temperature significantly increased, precipitation did not change significantly over the long term. Four relationships between weather and grain yield were evaluated to be significant: (a) the mean temperature in February (r = -0.4) and the precipitation in (b) February (r = -0.4), (c) March (r = -0.4), and (d) May (r = 0.5). The yield trends for all the fertilizer treatments increased, including the unfertilized control. The N3PK treatment provided the highest mean grain yields, while the unfertilized control had the lowest yields. Comparing the preceding crops, the highest yields were harvested when the wheat followed the legumes. On the other hand, the cereals were evaluated as the least suitable preceding crop in terms of grain yield. According to the linear-plateau model, the optimal nitrogen (N) dose for modern wheat varieties, following legumes and under the trial's soil climate conditions, was 131 kg ha-1 N, corresponding to a mean grain yield of 8.2 t ha-1.

QTL mapping for the flag leaf-related traits using RILs derived from Trititrigia germplasm line SN304 and wheat cultivar Yannong15 in multiple environments.

BACKGROUND: Developing and enriching genetic resources plays important role in the crop improvement. The flag leaf affects plant architecture and contributes to the grain yield of wheat (Triticum aestivum L.). The genetic improvement of flag leaf traits faces problems such as a limited genetic basis. Among the various genetic resources of wheat, Thinopyrum intermedium has been utilized as a valuable resource in genetic improvement due to its disease resistance, large spikes, large leaves, and multiple flowers. In this study, a recombinant inbred line (RIL) population was derived from common wheat Yannong15 and wheat-Th. intermedium introgression line SN304 was used to identify the quantitative trait loci (QTL) for flag leaf-related traits. RESULTS: QTL mapping was performed for flag leaf length (FLL), flag leaf width (FLW) and flag leaf area (FLA). A total of 77 QTLs were detected, and among these, 51 QTLs with positive alleles were contributed by SN304. Fourteen major QTLs for flag leaf traits were detected on chromosomes 2B, 3B, 4B, and 2D. Additionally, 28 QTLs and 8 QTLs for flag leaf-related traits were detected in low-phosphorus and drought environments, respectively. Based on major QTLs of positive alleles from SN304, we identified a pair of double-ended anchor primers mapped on chromosome 2B and amplified a specific band of Th. intermedium in SN304. Moreover, there was a major colocated QTL on chromosome 2B, called QFll/Flw/Fla-2B, which was delimited to a physical interval of approximately 2.9 Mb and contained 20 candidate genes. Through gene sequence and expression analysis, four candidate genes associated with flag leaf formation and growth in the QTL interval were identified. CONCLUSION: These results promote the fine mapping of QFll/Flw/Fla-2B, which have pleiotropic effects, and will facilitate the identification of candidate genes for flag leaf-related traits. Additionally, this work provides a theoretical basis for the application of Th. intermedium in wheat breeding.

Characterization of a wheat stable QTL for spike length and its genetic effects on yield-related traits.

Spike length (SL) is one of the most important agronomic traits affecting yield potential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population, KJ-RILs, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). The qSl-2B QTL was mapped to the 60.06-73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. Moreover, in the KJ-RILs population, the additive effects analysis of qSl-2B showed that additive effect was higher when both qSl-2D and qSl-5A harbor negative alleles under LN and HN. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2B continues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies.

Temperature fluctuation in soil alters the nanoplastic sensitivity in wheat.

Despite the wide acknowledgment that plastic pollution and global warming have become serious agricultural concerns, their combined impact on crop growth remains poorly understood. Given the unabated megatrend, a simulated soil warming (SWT, +4 °C) microcosm experiment was carried out to provide a better understanding of the effects of temperature fluctuations on wheat seedlings exposed to nanoplastics (NPs, 1 g L-1 61.71 ±â€¯0.31 nm polystyrene). It was documented that SWT induced oxidative stress in wheat seedlings grown in NPs-contaminated soil, with an 85.56 % increase in root activity, while decreasing plant height, fresh weight, and leaf area by 8.72 %, 47.68 %, and 15.04 % respectively. The SWT also resulted in reduced photosynthetic electron-transfer reaction and Calvin-Benson cycle in NPs-treated plants. Under NPs, SWT stimulated the tricarboxylic acid (TCA) metabolism and bio-oxidation process. The decrease in photosynthesis and the increase in respiration resulted in an 11.94 % decrease in net photosynthetic rate (Pn). These results indicated the complicated interplay between climate change and nanoplastic pollution in crop growth and underscored the potential risk of nanoplastic pollution on crop production in the future climate.

Foliar application of plant-derived peptides decreases the severity of leaf rust (Puccinia triticina) infection in bread wheat (Triticum aestivum L.).

BACKGROUND: Screening and developing novel antifungal agents with minimal environmental impact are needed to maintain and increase crop production, which is constantly threatened by various pathogens. Small peptides with antimicrobial and antifungal activities have been known to play an important role in plant defense both at the pathogen level by suppressing its growth and proliferation as well as at the host level through activation or priming of the plant's immune system for a faster, more robust response against fungi. Rust fungi (Pucciniales) are plant pathogens that can infect key crops and overcome resistance genes introduced in elite wheat cultivars. RESULTS: We performed an in vitro screening of 18 peptides predominantly of plant origin with antifungal or antimicrobial activity for their ability to inhibit leaf rust (Puccinia triticina, CCDS-96-14-1 isolate) urediniospore germination. Nine peptides demonstrated significant fungicidal properties compared to the control. Foliar application of the top three candidates, ß-purothionin, Purothionin-α2 and Defensin-2, decreased the severity of leaf rust infection in wheat (Triticum aestivum L.) seedlings. Additionally, increased pathogen resistance was paralleled by elevated expression of defense-related genes. CONCLUSIONS: Identified antifungal peptides could potentially be engineered in the wheat genome to provide an alternative source of genetic resistance to leaf rust.

pH change accompanying long-distance electrical signal controls systemic jasmonate biosynthesis.

Local damaging stimuli cause a rapid increase in the content of the defense phytohormone jasmonic acid (JA) and its biologically active derivative jasmonoyl-L-isoleucine (JA-Ile) in undamaged distal tissues. The increase in JA and JA-Ile levels was coincident with a rapid decrease in the levels of the precursor 12-oxo-phytodienoic acid (OPDA). The propagation of a stimulus-induced long-distance electrical signal, variation potential (VP), which is accompanied by intracellular changes in pH and Ca2+ levels, preceded systemic changes in jasmonate content. The decrease in pH during VP, mediated by transient inactivation of the plasma membrane H+-ATPase, induced the conversion of OPDA to JA, probably by regulating the availability of the OPDA substrate to JA biosynthetic enzymes. The regulation of systemic synthesis of JA and JA-Ile by the Ca2+ wave accompanying VP most likely occurs by the same mechanism of pH-induced conversion of OPDA to JA due to Ca2+-mediated decrease in pH as a result of H+-ATPase inactivation. Thus, the transient increase in intracellular Ca2+ levels and the transient decrease in intracellular pH are most likely the key mechanisms of VP-mediated regulation of jasmonate production in systemic tissues upon local stimulation.

Genetic Analysis of Adaptive Traits in Spring Wheat in Northeast China.

The dissection of the genetic architecture and the detection of the loci for adaptive traits are important for marker-assisted selection (MAS) for breeding. A spring wheat diversity panel with 251 cultivars, mainly from China, was obtained to conduct a genome-wide association study (GWAS) to detect the new loci, including the heading date (HD), maturating date (MD), plant height (PH), and lodging resistance (LR). In total, 41 loci existing in all 21 chromosomes, except for 4A and 6B, were identified, and each explained 4.3-18.9% of the phenotypic variations existing in two or more environments. Of these, 13 loci are overlapped with the known genes or quantitative trait loci (QTLs), whereas the other 28 are likely to be novel. The 1A locus (296.9-297.7 Mb) is a multi-effect locus for LR and PH, whereas the locus on chromosome 6D (464.5-471.0 Mb) affects both the HD and MD. Furthermore, four candidate genes for adaptive traits were identified, involved in cell division, signal transduction, and plant development. Additionally, two competitive, allele-specific PCR (KASP) markers, Kasp_2D_PH for PH and Kasp_6D_HD for HD, were developed and validated in another 162 spring wheat accessions. Our study uncovered the genetic basis of adaptive traits and provided the associated SNPs and varieties with more favorable alleles for wheat MAS breeding.

Characterization of sucrose nonfermenting-1-related protein kinase 2 (SnRK2) gene family in Haynaldia villosa demonstrated SnRK2.9-V enhances drought and salt stress tolerance of common wheat.

BACKGROUND: The sucrose nonfermenting-1-related protein kinase 2 (SnRK2) plays a crucial role in responses to diverse biotic/abiotic stresses. Currently, there are reports on these genes in Haynaldia villosa, a diploid wild relative of wheat. RESULTS: To understand the evolution of SnRK2-V family genes and their roles in various stress conditions, we performed genome-wide identification of the SnRK2-V gene family in H. villosa. Ten SnRK2-V genes were identified and characterized for their structures, functions and spatial expressions. Analysis of gene exon/intron structure further revealed the presence of evolutionary paths and replication events of SnRK2-V gene family in the H. villosa. In addition, the features of gene structure, the chromosomal location, subcellular localization of the gene family were investigated and the phylogenetic relationship were determined using computational approaches. Analysis of cis-regulatory elements of SnRK2-V gene members revealed their close correlation with different phytohormone signals. The expression profiling revealed that ten SnRK2-V genes expressed at least one tissue (leave, stem, root, or grain), or in response to at least one of the biotic (stripe rust or powdery mildew) or abiotic (drought or salt) stresses. Moreover, SnRK2.9-V was up-regulated in H. villosa under the drought and salt stress and overexpressing of SnRK2.9-V in wheat enhanced drought and salt tolerances via enhancing the genes expression of antioxidant enzymes, revealing a potential value of SnRK2.9-V in wheat improvement for salt tolerance. CONCLUSION: Our present study provides a basic genome-wide overview of SnRK2-V genes in H. villosa and demonstrates the potential use of SnRK2.9-V in enhancing the drought and salt tolerances in common wheat.

Fine mapping of leaf delayed virescence gene dv4 in Triticum aestivum.

Wheat (Triticum aestivum L.) is one of the most important crops worldwide, and its yield affects national food security. Wheat leaves are key photosynthetic organs where carbohydrates are synthesized for grain yield. Leaf colour mutants are ideal germplasm resources for molecular genetic studies of wheat chloroplast development, chlorophyll synthesis and photosynthesis. We obtained a wheat mutant delayed virescence 4 (dv4) from cultivar Guomai 301. The leaves of mutant dv4 were pale yellow at the seedling stage, golden yellow at the turning green stage, and they started to turn green at the jointing stage. Genetic analysis demonstrated that the yellow-leaf phenotype was controlled by a single recessive gene named as dv4. Gene dv4 was fine mapped in a 1.46 Mb region on chromosome 7DS by SSR and dCAPS marker assays. Three putative candidate genes were identified in this region. Because no leaf colour genes have been reported on wheat chromosome arm 7DS previously, dv4 is a novel leaf colour gene. The result facilitates map-based cloning of dv4 and provides information for the construction of a high-photosynthetic efficiency ideotype for improving wheat yield.

Genome-wide analysis for root and leaf architecture traits associated with drought tolerance at the seedling stage in a highly ecologically diverse wheat population.

Drought stress occurred at early growth stages in wheat affecting the following growth stages. Therefore, selecting promising drought-tolerant genotypes with highly adapted traits at the seedling stage is an important task for wheat breeders and geneticists. Few research efforts were conducted on the genetic control for drought-adaptive traits at the seedling stage in wheat. In this study, a set of 146 highly diverse spring wheat core collections representing 28 different countries was evaluated under drought stress at the seedling stage. All genotypes were exposed to drought stress for 13 days by water withholding. Leaf traits including seedling length, leaf wilting, days to wilting, leaf area, and leaf rolling were scored. Moreover, root traits such as root length, maximum width, emergence angle, tip angle, and number of roots were scored. Considerable significant genetic variation was found among all genotypes tested in these experiments. The heritability estimates ranged from 0.74 (leaf witling) to 0.99 (root tip angle). A set of nine genotypes were selected and considered drought-tolerant genotypes. Among all leaf traits, shoot length had significant correlations with all root traits under drought stress. The 146 genotypes were genotyped using the Infinium Wheat 15 K single nucleotide polymorphism (SNP) array and diversity arrays technology (DArT) marker platform. The result of genotyping revealed 12,999 SNPs and 2150 DArT markers which were used to run a genome-wide association study (GWAS). The results of GWAS revealed 169 markers associated with leaf and root traits under drought stress. Out of the 169 markers, 82 were considered major quantitative trait loci (QTL). The GWAS revealed 95 candidate genes were identified with 53 genes showing evidence for drought tolerance in wheat, while the remaining candidate genes were considered novel. No shared markers were found between leaf and root traits. The results of the study provided mapping novel markers associated with new root traits at the seedling stage. Also, the selected genotypes from different countries could be employed in future wheat breeding programs not only for improving adaptive drought-tolerant traits but also for expanding genetic diversity.

Prediction of biomass accumulation and tolerance of wheat seedlings to drought and elevated temperatures using hyperspectral imaging.

Early prediction of important agricultural traits in wheat opens up broad prospects for the development of approaches to accelerate the selection of genotypes for further breeding trials. This study is devoted to the search for predictors of biomass accumulation and tolerance of wheat to abiotic stressors. Hyperspectral (HS) and chlorophyll fluorescence (ChlF) parameters were analyzed as predictors under laboratory conditions. The predictive ability of reflectance and normalized difference indices (NDIs), as well as their relationship with parameters of photosynthetic activity, which is a key process influencing organic matter production and crop yields, were analyzed. HS parameters calculated using the wavelengths in Red (R) band and the spectral range next to the red edge (FR-NIR) were found to be correlated with biomass accumulation. The same ranges showed potential for predicting wheat tolerance to elevated temperatures. The relationship of HS predictors with biomass accumulation and heat tolerance were of opposite sign. A number of ChlF parameters also showed statistically significant correlation with biomass accumulation and heat tolerance. A correlation between HS and ChlF parameters, that demonstrated potential for predicting biomass accumulation and tolerance, has been shown. No predictors of drought tolerance were found among the HS and ChlF parameters analyzed.

Characterization of a partially saturated and glycosylated apocarotenoid from wheat that is depleted upon leaf rust infection.

Recent semi-targeted metabolomics studies have highlighted a number of metabolites in wheat that associate with leaf rust resistance genes and/or rust infection. Here, we report the structural characterization of a novel glycosylated and partially saturated apocarotenoid, reminiscent of a reduced form of mycorradicin, (6E,8E,10E)-4,9-dimethyl-12-oxo-12-((3,4,5-trihydroxy-6-(2-hydroxyethoxy)tetrahydro-2H-pyran-2-yl)methoxy)-3-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)dodeca-6,8,10-trienoic acid, isolated from Triticum aestivum L. (Poaceae) variety 'Thatcher' (Tc) flag leaves. While its accumulation was not associated with any of Lr34, Lr67 or Lr22a resistance genes, infection of Tc with leaf rust was found to deplete it, consistent with the idea of this metabolite being a glycosylated-storage form of an apocarotenoid of possible relevance to plant defense. A comparative analysis of wheat transcriptomic changes shows modulation of terpenoid, carotenoid, UDP-glycosyltransferase and glycosylase -related gene expression profiles, consistent with anticipated biosynthesis and degradation mechanisms. However, details of the exact nature of the relevant pathways remain to be validated in the future. Together these findings highlight another example of the breadth of unique metabolites underlying plant host-fungal pathogen interactions.

The effect of sulphur supplementation on cadmium phytotoxicity in wheat and lettuce: changes in physiochemical properties of roots and accumulation of phytochelatins.

Intensive sulphur fertilisation has been reported to improve the nutrient balance and growth of Cd-exposed plants, but the reasons of this phenomenon and the role of sulphur compounds in the resistance to cadmium are unclear. We investigated sulphur supplementation-induced changes in the surface properties of roots and the level of thiol peptides (PCs) in Cd-stressed Triticum aestivum L. (monocots clade) and Lactuca sativa L. (dicots clade) grown in nutrient solution. The combination of three sulphur (2 mM S-basic level, 6 or 9 mM S-elevated levels) and four cadmium (0, 0.0002, 0.02 or 0.04 mM Cd) concentrations was used. The physicochemical parameters of the roots were determined based on the apparent surface area (Sr), total variable surface charge (Q), cation exchange capacity (CEC) and surface charge density (SCD). In Cd-exposed plants supplied with sulphur, a different character and trend in the physicochemical changes (adsorption and ion exchange) of roots were noted. At the increased sulphur levels, as a rule, the Sr, CEC, Q and SCD values clearly increased in the lettuce but decreased in the wheat in the entire range of the Cd concentrations, except the enhanced Sr of wheat supplied with 6 mM S together with elevated (0.0002 mM) and unchanged (0.02, 0.04 mM Cd) value of this parameter at 9 mM S. This indicates a clade-specific and/or species-specific plant reaction. The 6 mM S appears to be more effective than 9 mM S in alleviation of the cadmium's toxic effects on roots. It was found that at 0.02 and 0.04 mM Cd, the use of 6 mM S limits the Cd accumulation in the roots of both species in comparison with the basic S fertilisation. Moreover, PC accumulation was much more efficient in wheat than in lettuce, and intensive sulphur nutrition generally induced biosynthesis of these chelating compounds. Physicochemical parameters together with quantitative and qualitative assessment of thiol peptides can be important indicators of the efficiency of root system functioning under cadmium stress. The differences between the species and the multidirectional character of the changes are a result of the involvement of a number of multi-level mechanisms engaged in the defence against metal toxicity.

Relationship between the baking quality of wheat (Triticum aestivum L.) and the protein composition and structure after shading.

Although wheat (Triticum aestivum L.) grain protein content is increased by shade stress, the relationship between the baking quality of wheat flour and protein composition and structure remains unclear. Here, we investigated the effects of shade stress on wheat flour protein composition and structure. The contents of the flour protein, α/ß-gliadins and disulfide and hydrogen bonds were significantly increased by shade stress. Glutenins, UPP%, and ß-sheet contents also increased, whereas that of α-helices decreased. Spearman correlations revealed that the flour protein content, Glu:Gli ratio, and disulfide, hydrogen, and ionic bonds can predict the specific volume and number of crumb cells in bread, whereas α/ß-gliadins content can predict the crumb cell wall thickness and diameter of bread. Under shade stress, variations in protein composition and structure help increase the specific volume and crumb cells number and decrease crumb cell wall thickness and diameter of bread, ultimately leading to improved baking quality.

Diversification of quantitative morphological traits in wheat.

BACKGROUND AND AIMS: The development and morphology of crop plants have been profoundly altered by evolution under cultivation, initially through unconscious selection, without deliberate foresight, and later by directed breeding. Wild wheats remain an important potential source of variation for modern breeders; however, the sequence and timing of morphological changes during domestication are not fully resolved. METHODS: We grew and measured 142 wheat accessions representing different stages in wheat evolution, including three independent domestication events, and compared their morphological traits to define the morphospace of each group. KEY RESULTS: The results show that wild and domesticated wheats have overlapping morphospaces, but each also occupies a distinct area of morphospace from one another. Polyploid formation in wheat increased leaf biomass and seed weight but had its largest effects on tiller loss. Domestication continued to increase the sizes of wheat leaves and seeds and made wheat grow taller, with more erect architecture. Associated changes to the biomass of domesticated wheats generated more grains and achieved higher yields. Landrace improvement subsequently decreased the numbers of tillers and spikes, to focus resource allocation to the main stem, accompanied by a thicker main stem and larger flag leaves. During the Green Revolution, wheat height was reduced to increase the harvest index and therefore yield. Modern wheats also have more erect leaves and larger flower biomass proportions than landraces. CONCLUSIONS: Quantitative trait history in wheat differs by trait. Some trait values show progressive changes in the same direction (e.g. leaf size, grain weight), whereas others change in a punctuated way at particular stages (e.g. canopy architecture), and other trait values switch directions during wheat evolution (e.g. plant height, flower biomass proportion). Agronomically valued domestication traits arose during different stages of wheat history, such that modern wheats are the product of >10 000 years of morphological evolution.

Variations in Cadmium and Lead Bioaccessibility in Wheat Cultivars and Their Correlations with Nutrient Components.

To reduce the health risks of exposure to Cd and Pb in wheat, a field experiment was conducted to investigate the differences in Cd and Pb bioaccessibility among the grains of 11 wheat cultivars and their relationships with the nutrient compositions of grains. The grain concentrations (Cd: 0.14-0.56 mg kg-1, Pb: 0.08-0.39 mg kg-1) and bioaccessibility (5.28-57.43% and 0.72-7.72% for Cd and Pb in the intestinal phase, respectively) of Cd and Pb differed significantly among the 11 cultivars. A safe wheat cultivar (Shannong16) with a relatively low health risk and the lowest grain Cd and Pb concentrations was selected. Ca, Mg, phytate, and methionine played key roles in affecting Cd and Pb bioaccessibility in wheat, with Ca and phytate significantly negatively correlated with Cd and Pb bioaccessibility. These findings can be used to optimize the selection strategy for safe wheat cultivars for healthy grain production in Cd-polluted farmland.

Effects of nano silicon fertilizer on the lodging resistance characteristics of wheat basal second stem node.

The application of nano fertilizers is one of the hotspots in current agricultural production. In this study, nano silicon materials were mixed with compound fertilizers to make nano silicon fertilizer. The effects of different amounts of nano silicon application on the breaking-resistance strength, lodging-resistance index, lignin accumulation, lignin synthesis related enzymes, and the relative expression of lignin synthesis related genes in the second stem node of wheat were mainly studied. Four treatments were set up: CK (750 kg·ha-1 compound fertilizer), T1 (750 kg·ha-1 compound fertilizer + 0.9 kg·ha-1 nano silicon), T2 (750 kg·ha-1 compound fertilizer + 1.8 kg·ha-1 nano silicon), T3 (750 kg·ha-1 compound fertilizer + 2.7 kg·ha-1 nano silicon). The results of the two-year experiment showed that the breaking-resistance strength, lodging-resistance index, lignin accumulation in the second stem node of wheat treated with nano silicon fertilizer were higher than CK. In the first year of the experiment, the lignin accumulation of T2 was 130.73%, 5.14% and 7.25% higher than that of CK, T1 and T3 respectively at the maturity stage. In the second year of the experiment, the lignin accumulation of T2 was 20.33%, 11.19% and 9.89% higher than that of CK, T1 and T3 respectively at the maturity stage. And the activities of PAL, 4CL, CAD, and related gene expression levels were also higher than CK. And among them, T2 performed the best, indicating that the application of nano silicon fertilizer is beneficial for improving the lodging resistance of wheat stems and is of great significance for improving the quality of wheat.

TaWRKY31, a novel WRKY transcription factor in wheat, participates in regulation of plant drought stress tolerance.

BACKGROUND: Wheat, a crucial food crop in China, is highly vulnerable to drought stress throughout its growth and development. WRKY transcription factors (TFs), being one of the largest families of TFs, play a vital role in responding to various abiotic stresses in plants. RESULTS: Here, we cloned and characterized the TF TaWRKY31 isolated from wheat. This TF, belonging to the WRKY II family, contains a WRKYGQK amino acid sequence and a C2H2-type zinc finger structure. TaWRKY31 exhibits tissue-specific expression and demonstrates responsiveness to abiotic stresses in wheat. TaWRKY31 protein is localized in the nucleus and can function as a TF with transcription activating activity at the N-terminus. Results showed that the wheat plants with silenced strains (BSMV:TaWRKY31-1as and BSMV:TaWRKY31-2as) exhibited poor growth status and low relative water content when subjected to drought treatment. Moreover, the levels of O2·-, H2O2, and malondialdehyde (MDA) in the BSMV:TaWRKY31-induced wheat plants increased, while the activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) decreased. Compared to control plants, BSMV:TaWRKY31-induced wheat plants exhibited lower expression levels of TaSOD (Fe), TaPOD, TaCAT, TaDREB1, TaP5CS, TaNCED1, TaSnRK2, TaPP2C, and TaPYL5.Under stress or drought treatment conditions, the overexpression of TaWRKY31 in Arabidopsis resulted in decreased levels of H2O2 and MDA, as well as reduced stomatal opening and water loss. Furthermore, an increase in resistance oxidase activity, germination rate, and root length in the TaWRKY31 transgenic Arabidopsis was observed. Lastly, overexpression of TaWRKY31 in Arabidopsis resulted in higher the expression levels of AtNCED3, AtABA2, AtSnRK2.2, AtABI1, AtABF3, AtP5CS1, AtSOD (Cu/Zn), AtPOD, AtCAT, AtRD29A, AtRD29B, and AtDREB2A than in control plants. CONCLUSIONS: Our findings indicate that TaWRKY31 enhances drought resistance in plants by promoting the scavenging of reactive oxygen species, reducing stomatal opening, and increasing the expression levels of stress-related genes.

Green Revolution dwarfing Rht genes negatively affected wheat floral traits related to cross-pollination efficiency.

Hybrid breeding is a promising strategy to quickly improve wheat yield and stability. Due to the usefulness of the Rht 'Green Revolution' dwarfing alleles, it is important to gain a better understanding of their impact on traits related to hybrid development. Traits associated with cross-pollination efficiency were studied using Near Isogenic Lines carrying the different sets of alleles in Rht genes: Rht1 (semi-dwarf), Rht2 (semi-dwarf), Rht1 + 2 (dwarf), Rht3 (extreme dwarf), Rht2 + 3 (extreme dwarf), and rht (tall) during four growing seasons. Results showed that the extreme dwarfing alleles Rht2 + 3, Rht3, and Rht1 + 2 presented the greatest effects in all the traits analyzed. Plant height showed reductions up to 64% (Rht2 + 3) compared to rht. Decreases up to 20.2% in anther length and 33% in filament length (Rht2 + 3) were observed. Anthers extrusion decreased from 40% (rht) to 20% (Rht1 and Rht2), 11% (Rht3), 8.3% (Rht1 + 2), and 6.5% (Rht2 + 3). Positive correlations were detected between plant height and anther extrusion, anther, and anther filament lengths, suggesting the negative effect of dwarfing alleles. Moreover, the magnitude of these negative impacts depends on the combination of the alleles: Rht2 + 3 > Rht3/Rht1 + 2 > Rht2/Rht1 > rht (tall). Reductions were consistent across genotypes and environments with interactions due to magnitude effects. Our results indicate that Rht alleles are involved in multiple traits of interest for hybrid wheat production and the need to select alternative sources for reduced height/lodging resistance for hybrid breeding programs.