The ERECTA family of receptor-like kinases (RLKs) plays a crucial regulatory role in plant stomatal development and responses to abiotic stresses. This study therefore focused on investigating the barley HvERECTA gene, aiming to clarify its regulatory roles in these biological processes and provide potential targets for barley drought resistance breeding. We first cloned the HvERECTA gene from barley and conducted comprehensive bioinformatics analyses to characterize its sequence and protein properties. Subsequently, we constructed a heterologous overexpression vector carrying the HvERECTA gene and transformed it into Arabidopsis thaliana. For the transgenic Arabidopsis lines, we systematically determined stomatal phenotypic traits, expression levels of the key related genes, and physiological indicators under drought stress conditions to evaluate the gene function. The bioinformatics analysis results showed that the full-length coding sequence (CDS) of HvERECTA is 2 934 bp, encoding a protein of 977 amino acids. The HvERECTA protein is localized to the plasma membrane and contains a typical serine/threonine protein kinase domain, which is a hallmark of the receptor-like kinase family. Sequence alignment and phylogenetic analysis revealed that HvERECTA is highly conserved among gramineous plants, with the highest homology to those from wheat (Triticum aestivum) and ryegrass (Lolium perenne). Additionally, analysis of cis-acting elements in the HvERECTA promoter region indicated that it is rich in regulatory elements associated with abiotic stress responses and plant hormone signaling, such as abscisic acid (ABA)-responsive elements (ABRE) and drought-responsive elements (MBS). Phenotypic observations on the transgenic Arabidopsis lines showed that overexpression of HvERECTA significantly reduced stomatal density compared with the wild-type control. Molecular analysis demonstrated that the expression levels of genes encoding key stomatal development transcription factors, namely SPCH (SPEECHLESS), MUTE, and FAMA, were all downregulated by more than 50% in the transgenic lines. In contrast, the expression level of YODA, a core gene in the mitogen-activated protein kinase (MAPK) cascade pathway that is involved in stomatal development regulation, was upregulated by 50%-80% in the transgenic plants. Under drought stress, the transgenic Arabidopsis lines showed enhanced drought resistance-related physiological performance. Specifically, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the transgenic lines were increased by 25%-40% compared with the control. Meanwhile, the content of malondialdehyde (MDA), which is an indicator of lipid peroxidation and cellular damage under stress, was decreased by approximately 30% in the transgenic lines. Additionally, the water loss rate of the transgenic lines was reduced by 20%, and their relative water content was higher than that of the control. Furthermore, the expression levels of stress-responsive genes, including AtKIN2, AtABF3, and AtRD22, showed no abnormal changes under normal growth conditions but were significantly upregulated under drought stress in the transgenic lines. In conclusion, the barley HvERECTA gene enhances plant drought resistance by regulating the MAPK signaling pathway to reduce stomatal density and by improving the activity of the plant antioxidant defense system. These two regulatory pathways collectively enhance the water retention capacity of plants under drought stress, thereby improving their stress tolerance. This study clarifies the important regulatory role of HvERECTA in stomatal development and abiotic stress response, and provides an important functional gene resource for drought-resistant molecular breeding of barley.

High mobility group (HMG) proteins are key regulators of chromatin dynamics in eukaryotes. To investigate the dynamic responses of the wheat HMG family to drought and phosphate starvation, a genome-wide identification of the TaHMG genes was performed based on the common wheat reference genome (IWGSC Ref Seq V1.0). Bioinformatic analyses were conducted to determine the physicochemical properties, phylogeny, collinearity, and promoter cis-elements of the family members. Public transcriptome data and quantitative real-time PCR (qRT-PCR) were integrated to examine tissue-specific expression patterns and temporal expression profiles under drought stress (15% PEG6000; 0, 1, 3, 6, 12, and 24 h) and phosphate starvation (0 μmol·L^-1 Pi; 0, 1, 3, 6, 12, and 24 h). A total of 32 TaHMG genes were identified, which were phylogenetically divided into two subfamilies: HMGA (9 members) and HMGB (23 members). Collinearity analysis indicated that the family evolved predominantly under purifying selection. Promoter analysis revealed that TaHMG genes are enriched in hormone and stress-responsive elements, including abscisic acid (ABRE) and methyl jasmonate (MeJA)-responsive motifs. qRT-PCR showed that Ta-6D-HMGB1, Ta-3D-HMGB1 and Ta-7D-HMGB2 were highly expressed in leaves, whereas Ta-2D-HMGB1, Ta-5A-HMGB1, and Ta-7D-HMGB1 were highly expressed in stems. Under drought stress, five TaHMG genes were rapidly induced at early stage (3 or 6 h), while Ta-7D-HMGB2 was initially suppressed (0-3 h) and subsequently up-regulated (6 h). Under phosphate starvation, expression peaks of different members occurred at 12 or 24 h post treatment, revealing temporal specificity and functional divergence among genes. Collectively, members of the wheat HMG family adapt to abiotic stresses through differential expression, and stress-responsive genes such as Ta-7D-HMG2 and Ta-3D-HMGB1 represent promising candidates for molecular breeding of stress tolerance.

Abstract:Agrobacterium-mediated transformation is an important approach for genetic modification of wheat, but it still suffers from several unresolved critical technical bottlenecks, including low transformation efficiency, strong genotype dependence, severe browning of calli, and low regeneration efficiency. In this study, immature embryos of the model cultivar Fielder were used as explants to systematically investigate the effects of embryo age, acetosyringone (AS) concentration and Agrobacterium infection duration, phosphinothricin (PPT) selection pressure, and exogenous hormone (abscisic acid, ABA; kinetin, KT) ratios on callus induction, regeneration and transformation efficiency. Using the optimized protocol, applicability was evaluated in the cultivars Yangmai 20, Zhengmai 7698, and Kenong 199. The results showed that embryos harvested 12 days after anthesis exhibited the lowest browning rate (4.40%) and were most suitable as recipients for transformation. When the Agrobacterium suspension was adjusted to OD₆₀₀=0.5, supplementation with 200 μmol·L^-1 AS and a 10 min infection produced the highest induction rate of resistant green callus spots (34.29%). Addition of 0.5 mg·L^-1 ABA to the induction medium and 1.5 mg·L^-1 KT to the regeneration medium significantly enhanced embryogenic callus formation and plant regeneration. The optimal PPT selection concentration was determined to be 10 mg·L^-1. Under the optimized conditions, transformation efficiency of Fielder increased significantly from 8.16% before optimization to 14.83%; transformation efficiencies of Yangmai 20, Zhengmai 7698, and Kenong 199 reached 9.03%, 7.32% and 8.70%, respectively, approaching or exceeding the pre-optimization level of Fielder. In summary, the optimized system established in this study improves wheat genetic transformation efficiency and is broadly applicable across different genetic backgrounds, providing a technical platform for gene functional analysis and molecular breeding in wheat.

To elucidate the molecular mechanism of miRNA in wheat's response to dry-hot wind stress, a sensitive germplasm Xinchun 14 and a tolerant variety Xinchun 46 were selected as materials. During the grain-filling stage, artificial simulation of dry-hot wind stress (daytime temperature 35 ℃/nighttime temperature 25 ℃, relative humidity 20%, wind speed 5 m·s^-1, continuous treatment for 5 days) was applied. High-throughput sequencing technology was used to screen differentially expressed miRNAs, followed by validation via qRT-PCR. The results showed that 203 miRNAs were involved in the expression under dry-hot wind stress, with 136 co-expressed miRNAs. After differential screening, six core differentially expressed miRNAs were ultimately identified, namely, novel_miR_537, novel_miR_443, novel_miR_469, novel_miR_393, novel_miR_390, and novel_miR_339. These miRNAs were significantly enriched in four pathways: the biosynthesis of mannose O-glycans, the degradation of polysaccharides, peroxisomes, and the metabolism of selenium compounds. Target gene predictions revealed that these miRNAs targeted and regulated key membrane protein-encoding genes, including β-1, 2-xyltransferase, α-1, 3-arabinosyltransferase, GDSL esterase/lipase, α-L-fucosidase, and peroxidase, and are involved in the maintenance of cell wall stability, reactive oxygen species clearance, and osmotic regulation processes. This indicates there is a miRNA regulatory network in the response of dry-hot wind in wheat, and it jointly participates in the resistance process of wheat to dry-hot wind stress in the form of a 'miRNA-targeted gene' molecular module.

To investigate genome-wide mRNA secondary structure reprogramming and its correlation with translation efficiency under heat stress in wheat, this study performed a multi-omics analysis on wheat seedlings (cv. Chinese Spring) under different conditions, utilizing SHAPE-MaP and polysome profiling. The results showed that the SHAPE reactivity of start and stop codon positions in wheat transcripts was significantly higher than that of flanking regions, exhibiting conserved structural features. Compared with the control, heat stress resulted in a decrease in the average SHAPE reactivity across transcripts, indicating that mRNA tends to form double-stranded structures. This change exhibited reversibility during recovery. At the early stage of heat stress, structural changes in the start codon region were the most significant. Polysome profiling showed that heat stress caused a decrease in polysome peaks, and translation was inhibited at the genome-wide level. Correlation analysis revealed that there was no significant correlation between SHAPE reactivity changes and translation efficiency changes of various functional regions at the genome-wide level. In summary, the heat-induced increase in mRNA folding may be a proactive defense strategy, which presents a non-linear complex relationship with translational regulation.

Plant height (PH) is an important agronomic trait affecting lodging resistance and yield in wheat. To dissect the genetic basis of PH and identify stable loci, we analyzed a natural population of 339 wheat accessions from the Huang-Huai wheat region using PH phenotypes collected across nine environments and genotypes obtained with a 21K single nucleotide polymorphism (SNP) array. Genome-wide association study (GWAS) was conducted using a mixed linear model (MLM). Linkage disequilibrium (LD) and haplotype analyses were performed for the key associated interval, and the association was further validated in a natural population of 327 accessions genotyped with a 660K SNP array. Candidate genes within the target interval were annotated and prioritized. In total, 66 stable QTLs significantly associated with PH were identified. A novel major and stable QTL, QPh. nwafu-6D, was detected on chromosome 6D (490.34-492.42 Mb) and was consistently detected in eight environments, explaining 8.23% of the phenotypic variance on average. The interval was divided into two LD blocks. In Block2, three haplotypes were identified, and the favorable haplotype Block2_Hap1 (frequency 84.1%) showed significantly reduced PH compared with other haplotypes and was significantly associated with higher thousand-kernel weight in multiple environments. In the validation population, accessions carrying the Block2_Hap1 genotype at the core SNP marker SNP_Chr6D_492211566 exhibited significantly lower PH than those with the Block2_Hap2 genotype (P< 0.001). Eight candidate genes were further prioritized in this interval, mainly involved in kinase signaling, transcriptional regulation, ubiquitin-mediated protein degradation, and hormone responses.

In order to explore the physiological and molecular response mechanism of highland barley seedlings to salt stress, ZYM1795, ZYM3130 and ZYM2239 highland barley seedlings were used as materials. The seedlings were treated with 50, 150, and 250 mmol·L^-1 NaCl solution and distilled water (control). The contents of malondialdehyde (MDA), total soluble sugar (SS) and the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) in the leaves of highland barley were determined. Transcriptome sequencing was performed on the leaves of the control and 250 mmol·L^-1 NaCl treatment. The results showed that with the increase of salt concentration, the MDA content of salt-tolerant materials increased first and then decreased; the activities of SOD, POD and CAT increased first and then decreased; and the SS content accumulated significantly, indicating that highland barley responded to salt stress by activating antioxidant defense system and osmotic adjustment substances. Through transcriptome analysis, a total of 3 343 differentially expressed genes that may be related to salt tolerance were identified. Through weighted gene co-expression network analysis, yellow modules significantly related to all physiological indicators were screened, and 1 801 potential salt tolerance-related genes were further obtained. GO enrichment analysis showed that these genes were mainly enriched in stress response, antioxidant defense, hormone signal transduction, such as abscisic acid response, enzyme activity regulation and other related pathways. Among them, 20 key genes were screened, including peroxidase gene, trehalose phosphorylase gene, serine/ threonine protein kinase gene, and ABC transporter gene. These genes play an important role in active oxygen scavenging, osmotic regulation, and signal transduction. It is speculated that highland barley seedlings enhance salt tolerance by synergistically regulating physiological response and key gene expression.

To clarify the effects of tracking photovoltaic (PV) panel shading on winter wheat growth in coastal saline-alkali land and screen shade-tolerant varieties, three wheat varieties (Hengmai 27, Jiemai 19, and Tongmai 6) were used as materials. In the photovoltaic array with a north-south orientation and a panel spacing of 10 m, planting areas (S_0-2 to S_8-10) were set every 2 m from west to east. The flag leaf photosynthetic parameters, chlorophyll fluorescence parameters, and yield components were determined. The results showed that: (1) PV panel shading exhibited a significant spatial gradient effect. The net photosynthetic rate (P_n) was highest in the central planting area S_4-6, reaching 18 μmol·m^-2·s^-1 in Hengmai 27, while edge planting areas showed a reduction rate of approximately 22%. There were significant differences in photosynthetic characteristics among varieties: Hengmai 27 maintained high and stable P_n and stomatal conductance (G_s); Jiemai 19 showed low P_n (6-8 μmol·m^-2·s^-1, only 40%-50% of Hengmai 27) but gentle fluctuations; Tongmai 6 exhibited severe fluctuations in P_n with a reduction rate exceeding 50%. Photosynthetic peak time delayed from the central belt toward both planting areas, reflecting the time-lag effect of east-west tracking PV panels. The high consistency among G_s, P_n, and transpiration rate (T_r) confirmed that stomata are the key regulators of photosynthesis and water loss. Hengmai 27, with high intercellular CO₂ concentration (C_i) and G_s, belonged to the non-stomatal limitation type; Jiemai 19, with the highest C_i but the lowest P_n, belonged to the photochemical limitation type; Tongmai 6, with fluctuating G_s and elevated C_i in late stage, belonged to the combined stomatal and photochemical limitation type. (2) The differences of chlorophyll fluorescence parameters among varieties revealed divergent photochemical adaptation strategies. The PSⅡ maximum photochemical efficiency (F_v/F_m) and actual photochemical efficiency (Φ_PSⅡ) of Hengmai 27 and Tongmai 6 were significantly higher than those of Jiemai 19 (P<0.05). However, Hengmai 27 had low initial fluorescence (F_o) with stable PS II basal state, while Tongmai 6 had high F_o indicating reversible damage to reaction centers. Jiemai 19 showed the most stable variable fluorescence (F_v) but the lowest F_v/F_m, adopting a defensive strategy dominated by thermal dissipation. (3) Yield analysis showed that the interaction of variety and planting area had significant effects on thousand-grain weight, grain yield, biomass, and harvest index (P<0.01), among which 1 000-grain weight was the most sensitive to shading. Hengmai 27 showed the smallest reduction in thousand-grain weight (2%-7%), with grain yield of 5 309.32 kg·hm^-2 and stable harvest index (50.23%-51.54%) in S_4-6, indicating coordinated source-sink relations. Jiemai 19 showed no significant change in thousand-grain weight under mild shading, but harvest index decreased to 46.03% in S_4-6, presenting source-sink imbalance with increased biomass but reduced harvest index. Tongmai 6 showed the largest reduction in thousand-grain weight (8%-18%), with grain yield of only 3 475.82 kg·hm^-2 in S_4-6, 34.5% lower than that of Hengmai 27. In conclusion, stomatal limitation is the main regulatory factor of photosynthetic variation. Hengmai 27 is a high-efficiency shade-tolerant variety, which is most suitable for planting in photovoltaic shading areas; Jiemai 19 has strong photoprotection ability and can be used as an alternative; Tongmai 6 has weak shade tolerance and is not suitable for the current conditions.

Xinjiang, especially in the southern Xinjiang region, precipitation is scarce and the climate is arid. Land in this area suffers from varying degrees of salinization, which affects wheat growth and leads to reduced yields. Screening salt-tolerant germplasm resources is an effective approach to improving grain production capacity in southern Xinjiang. In this study, 42 spring wheat varieties approved and released in the Yellow River Irrigation District of Ningxia and its surrounding areas were used as experimental materials. Under 150 mmol·L^-1 NaCl stress, germination and phenotypic indices were measured at the germination and seedling stages, and relative values of the 13 indices were calculated to comprehensively evaluate the salt tolerance of different varieties. The results showed that the relative values of most indices at the germination and seedling stages were below 100%. The coefficients of variation for germination energy, germination index, and vigor index at the germination stage exceeded 20%. At the seedling stage, the coefficients of variation for seedling height, above-ground fresh weight, above-ground dry weight, root dry weight, and root length were greater than 20%. Significant positive correlations were observed among the indices. The tested materials were classified into three categories via hierarchical cluster analysis: 15 salt-tolerant genotypes, 20 intermediate genotypes, and 7 sensitive genotypes. Ningchun 3, Ningchun 8, Ningchun 9, Ningchun 12, and Ningchun 35 exhibited superior salt tolerance and strong stress adaptability, which preliminarily verifies the feasibility of cross-regional introduction of Ningchun spring wheat germplasm resources, and providing material basis and methodological reference for breeding new salt-tolerant wheat varieties in southern Xinjiang.

To investigate the effects of foliar application of chelated titanium on dry matter accumulation and yield formation in late-sown winter wheat in Xinjiang, as well as to determine the optimal application timing and concentration, the study used Xindong 18, a winter wheat cultivar cultivated in the Ta'er Basin of Xinjiang. A two-factor split-plot field experiment was conducted at the demonstration base of the Tacheng Agricultural Science Research Institute in the Ta'er Basin from 2023 to 2025. The main plots were set up with two foliar application stages: the booting stage (D1) and the flowering stage (D2). The subplots were set up with four application concentrations: 0 μmol·L^-1 (C0, distilled water control), 376 μmol·L^-1 (C1), 501 μmol·L^-1 (C2), and 626 μmol·L^-1 (C3). We measured and analyzed the characteristics of wheat agronomic traits, dry matter, grain filling progress, yield, and yield components under different treatments. The results showed that under D1 conditions, compared with C0, C2 exhibited the greatest increases in wheat plant height, average stem diameter, and spike length in both years. In 2023—2024 and 2024—2025, dry matter accumulation of C2 increased by 25.57% and 14.20%, yield increased by 5.06% and 9.45%, respectively, while dry matter transport efficiency, grain filling rate, grain filling duration, and number of grains per spike all increased significantly. Under D2 conditions, the application of chelated titanium had no significant effect on wheat plant height, average stem diameter, or spike length; compared to C0, dry matter accumulation in C2 increased by 20.99% and 15.35%, yeid increased by 4.65% and 6.54% for the two consecutive years, respectively, while dry matter transport rate, grain filling rate, grain filling duration, and thousand-kernel weight all increased significantly. Overall, the D1C2 treatment had the best effect on promoting the growth and increasing the yield of late-sown winter wheat, which can address the yield reduction issues caused by reduced dry matter accumulation and shortened grain-filling duration in late-sown winter wheat.