To elucidate the promoter of the barley LRR-type receptor-like protein kinase gene HvLRR-RLK510 and its function, specific PCR primers were used to amplify the promoter of the HvLRR-RLK510 gene from Morex and Baodamai 8. The pEASY®-510 recombinant plasmid was constructed, and the promoter sequence of 2 368 bp was sequenced based on the positive colonies of the Escherichia coli Trans1-T₁ strain. The prediction results from the online software PlantCARE indicated that the promoter contains response elements to non-biotic factors such as methyl jasmonate, abscisic acid, and low temperature. GUS staining results in roots, stems, leaves, and flowers of transgenic Arabidopsis thaliana and transiently expressed Nicotiana benthamiana plants demonstrated that the cloned promoter and its truncated fragments (-1 458, -868, and -460 bp) can equivalently drive the expression of the GUS gene in anthers. Quantitative real-time PCR (qRT-PCR) results showed that methyl jasmonate (MeJA), abscisic acid (ABA), low temperature, polyethylene glycol (PEG-2000), and light can effectively alter the expression characteristics of the HvLRR-RLK510 gene in barley leaves and roots. The promoter of the HvLRR-RLK510 gene cloned in this study is an inducible promoter containing response elements to jasmonic acid, abscisic acid, low temperature, drought, and light. Its -460 bp truncated fragment can replace the full-length promoter. The promoter and its truncated fragments can be used to elucidate the transcriptional regulatory mechanisms of the HvLRR-RLK510 gene.

Plant height is a key trait in the growth and development of wheat and has an important impact on wheat yield. To further identify quantitative trait loci (QTL) associated with plant height in wheat, this study utilized an F₂ population derived from a cross between a dwarf mutant 20DH2-2 and a tall parent 21Hs-7. Genetic analysis of plant height was conducted using a mixed dominant gene plus multi-gene inheritance model. A genetic linkage map was constructed using the screening results of 620 simple sequence repeat (SSR) molecular markers, and QTL mapping analysis was performed in combination with the plant height phenotypic data of the F₂ individuals. Results showed that the optimal genetic model for plant height was 2MG-EA (two equal additive major genes). Through bulked segregant analysis (BSA), 26 polymorphic SSR markers were identified, constructing a genetic linkage map spanning 531.62 cM. Five plant height-related QTLs were detected on chromosomes 2A (two QTLs), 4A, 5A, and 6A, with logarithm of odds (LOD scores) ranging from 2.60 to 8.19 and explaining 7.97%~22.88% of phenotypic variation. Specifically, QPH-nwafu-2A.2, QPH-nwafu-4A, QPH-nwafu-5A, and QPH-nwafu-6A tightly linked to molecular markers BQ838266 (4.01 cM), Xwmc262 (3.00 cM), Xwmc524 (3.94 cM), and Xbarc107 (0.69 cM), respectively.

To provide excellent germplasm resources for wheat breeding against powdery mildew (a major disease affecting wheat production), this study evaluated the adult plant resistance (APR) of 96 wheat varieties (lines) from diverse sources to powdery mildew under natural infection and artificial inoculation in Yunnan and Zhejiang. Molecular markers for 13 known Pm genes were used to screen the materials. Results showed that 67 varieties (lines) exhibited resistance, including 28 highly resistant (HR) materials (29.17%). Resistance genes were detected in 62 materials, with Pm4b having the highest detection frequency, followed by Pm21. In terms of gene composition, materials carrying a single resistance gene predominated (58.1%), while only one material combined five different Pm genes. Notably, resistance genes Pm2, Pm4a, Pm4b, Pm8, Pm18, Pm34, Pm35, and Pm52 were detected in some susceptible materials, indicating their resistance may have been overcome by the pathogen. In contrast, Pm21, Pm24, Pm26, Pm57, and PmTm4 retained stable resistance.

Wheat yellow mosaic disease, caused by wheat yellow mosaic virus (WYMV) and transmitted via the soil-borne vector Polymyxa graminis, is one of the most devastating soil-borne viral diseases affecting wheat production in China. In recent years, its incidence in the Huang-Huai wheat-growing region has shown an escalating trend, posing significant challenges for disease control. This study aimed to screen elite germplasms and genetic resources resistant to wheat yellow mosaic disease by conducting phenotypic evaluations and molecular marker detection for major resistance genes. Field resistance assessments were performed on 158 wheat varieties (lines) across three environments over two consecutive years in the Huang-Huai region, and genotype screening was carried out using molecular markers linked to major resistance genes/QTLs. Phenotypic analysis revealed that 26, 35 and 10 accessions were consistently classified as immune, highly resistant and moderately resistant to WYMV across all three environments, accounting for 16.5%, 22.2% and 6.3% of the total, respectively. In contrast, 72(45.5%) and 15(9.5%) varieties (lines) were moderately susceptible and highly susceptible, respectively. Molecular marker detection identified 39(24.7%), 48(30.4%) and 3(1.9%) accessions carrying the resistance genes/QTLs QYm.nau-2D, Ym2 and QYm.njau-5A.1, respectively. Notably, accessions individually carrying QYm.nau-2D, QYm.njau-5A.1 or the combination of QYm.nau-2D and Ym2 exhibited enhanced disease resistance. Based on integrated phenotypic and genotypic analyses, 61 immune or highly resistant wheat varieties (lines), including Yunong 907, Yunong 908, Zhoumai 30, were identified as valuable genetic resources for breeding and deployment of WYMV-resistant wheat varieties. These materials provide a foundation for improving disease-resistant germplasms and exploring novel resistance genes.

Kenya Kudu, a Kenyan wheat variety, exhibits robust adult plant resistance (APR) to leaf rust. To dissect the genetic architecture underlying this resistance, we conducted quantitative trait locus (QTL) mapping using 195 F_2∶3 lines derived from a cross between Kenya Kudu and the susceptible cultivar Zhengzhou 5389. Field evaluations were carried out in Baoding, Hebei Province and Zhoukou, Henan Province during the 2017-2018 and 2018-2019 growing seasons. Plants were inoculated with a mixture of virulent Puccinia triticina (Pt) races to assess APR. Phenotypic data on disease severity were integrated with genotypic data from 660K SNP array and SSR markers for QTL analysis. The results demonstrated that three novel adult plant resistance QTLs to leaf rust were identified on wheat chromosomes 2B and 5B. Two QTLs were located on chromosome 5B, provisionally designated as QLr.hbau-5B.1 and QLr.hbau-5B.2, accounting for 8.3~10.5% and 6.9~8.6% of the phenotypic variation, respectively. One QTL located on chromosome 2B, provisionally designated QLr.hbau-2B, accounted for 7.2~10.6% of the phenotypic variation and may correspond to a known leaf rust resistance locus. These results demonstrate that Kenya Kudu's resistance is attributed to the additive effects of multiple minor-effect QTLs. The identified QTLs and their closely linked molecular markers offer critical genetic tools for marker-assisted selection (MAS) in breeding wheat cultivars with durable resistance to leaf rust.

5-aminolevulinic acid (5-ALA), as a novel plant growth regulator, has been widely applied in alleviating abiotic stress in plants. In this study, a wheat cultivar Yangmai 25 was used as the experimental material to investigate the effects of seed soaking with different concentrations of 5-ALA (0, 5, 10, 25, 50, and 100 mg·L^-1) on seed germination, material activation, energy supply, as well as ionic and redox homeostasis under salt stress simulated by 100 mmol·L^-1 NaCl solution. The objectives were to identify the optimal concentration of 5-ALA for enhancing salt tolerance in wheat seeds and to elucidate its physiological mechanisms. The results demonstrated that seed soaking with 5-ALA (5-100 mg·L^-1) markedly shortened the mean germination time of wheat seeds under salt stress by 0.23-0.42 days and significantly promoted the growth of both radicle and coleoptile. Further analysis revealed that 25 mg·L^-1 5-ALA priming increased wheat swelling rates, as well as the activities of amylase, 6-phosphofructokinase, and hexokinase under salt stress, along with enhanced respiration rates and adenosine triphosphate (ATP) content, while significantly reducing starch and soluble sugar contents in wheat. Although 5-ALA priming did not mitigate excessive Na⁺ accumulation in wheat under salt stress, it effectively inhibited K⁺ loss induced by salt stress. Moreover, 5-ALA priming significantly reduced malondialdehyde (MDA) accumulation in wheat under salt stress. These findings suggest that 5-ALA seed priming promotes wheat seed germination and growth under salt stress by accelerating starch degradation, maintaining energy supply levels, and preserving ionic and redox homeostasis.

In order to further explore the quantitative trait locus (QTL) for tillering-related traits in wheat, and to explore the genetic relationship between tillering traits, we used 255 recombinant inbred lines (RIL) populations, constructed from Apache and Xindong 36, as research materials to determine several key metrics. These included the number of pre-winter tillers, the number of single tillers, the number of effective tillers, the effective tillers per unit area, and the tiller angle. The phenotypic values of spike rate were determined in four environments. The QTL controlling tillering-related traits was carried out based on the ultra-low depth sequencing data of the RIL populations. The results showed that a total of 53 QTLs for tillering traits were detected on 15 chromosomes, including 13 QTLs for pre-winter tiller number, 10 QTLs for single-plant tiller number, 8 QTLs for effective tiller number per plant, 11 QTLs for effective tiller number per unit area, 4 QTLs for tiller angle, 2 QTLs for spike-forming rate, and 5 pleiotropism QTLs. The phenotypic interpretation rates of individual QTLs ranged from 2.66% to 28.76%. Among them, QTn.xjau-4B was detected in all three environments, with a phenotypic contribution rate of 28.76% to the effective number of tillers of a single plant. This stable QTL is a major effective and R-E-Z locus, which can be used as an important locus for the study of tillering and plant type.

Methyl jasmonate (MeJA) can induce flowering habits. In order to further elucidate the regulatory role of MeJA on the flowering habits, lodicule morhpology, and outcrossing seed setting rate of photo-thermo sensitive male sterile lines of wheat, this study immersed the wheat line BS141 with 4 mmol·L^-1 MeJA at 2 days post-anthesis, using water-immersed spikes as a control. The effects of MeJA on the daily anthesis rate, temporal variations in flowering, the glume opening rate, anthesis angle, lemma morphology, and outcrossing seed setting were investigated. The results demonstrated that upon treatment with MeJA, the glume opening rate of the BS141 peaked on the day of treatment, showing an increase of 31.45 percentage points compared to the control group. However, starting from the second day, this number was significantly lower than that of the control. From the fourth to the fifth day, there was no significant difference compared with the control. Pollination at the time when the glume opening rate was the highest increased the outcrossing seed setting rate of BS141 by 24.77 percentage points compared with the control. The peak flowering period of the MeJA-treated BS141 was predominantly concentrated at 13:00, whereas the control was more dispersed. The stigma exsertion rate of BS141 was statistically analyzed at 10:00 a.m. It was found that the stigma exsertion rate of BS141 treated with MeJA was lower than that of the control within 5 days. The overall maximum daily opening angle of BS141 treated with MeJA was lower than that of the control group. Therefore, by spraying exogenous MeJA, the glume opening rate of wheat photo-thermo sensitive male sterile line could be maximized on the day of spraying, and the flowering peak was relatively concentrated. At this time, pollination could significantly increase the outcrossing seed setting rate. However, spraying MeJA had no significant effect on the stigma exsertion rate and the maximum opening angle.

The GATA gene family is a crucial class of transcriptional regulators in plants, widely involved in plant growth, development, and various physiological and biochemical processes. In this study, a comprehensive genome-wide analysis of the barley GATA transcription factor family was performed using bioinformatics approaches, including gene identification, structural characterization, collinearity analysis, promoter element prediction, and expression pattern profiling. The results showed that the barley genome contains a total of 27 GATA genes (designated as HvGATA01-HvGATA27), which were unevenly distributed across the 7 chromosomes. Gene structure analysis revealed that the number of introns in HvGATA genes ranged from 0 to 7, with distinct intron-exon arrangements observed among different subgroups. All members contain the typical GATA conserved domain. Phylogenetic analysis divided them into five subgroups (S1-S5), of which subgroup S5 contains 9 members, while subgroup S3 has only one member. Except for S3, the remaining subgroups existed before the divergence of monocots and dicots. Collinearity analysis revealed that collinear GATA gene pairs exist between the barley genome and those of rice, Arabidopsis thaliana, Brachypodium distachyon, soybean, and tomato. Notably, the number of collinear gene pairs in barley-rice and barley-Brachypodium distachyon comparisons was significantly higher than that in the other three species. Cis-acting element analysis indicated that the promoter regions of barley GATA genes are enriched with light-responsive elements and hormone signaling-related elements. Expression profiling showed significant differential expression patterns across 16 barley tissues, with most HvGATA genes exhibiting high expression in inflorescence tissues, while low expression was observed in deglumed grains, suggesting their potential involvement in barley flowering development regulation.

To analyze the genetic rules of agronomic traits related to wheat yield, in this study, 319 wheat materials and 16K SNP array data were utilized. Through the method of genome-wide association study (GWAS), seven yield-related traits, namely plant height, spike length, number of spikelets per spike, 1 000-grain weight, grain length, grain width, and grain length-to-width ratio, were analyzed in five environments. The results showed that all the seven traits exhibited extensive phenotypic variations, with the coefficient of variation ranging from 5.97% to 15.77%, and the broad-sense heritability ranging from 82.42% to 96.62%. The results of the genome-wide association analysis indicated that a total of 98 significant and stable SNP loci were detected in five environments, explaining 2.9% to 12.1% of the phenotypic variations. Among them, three SNP loci, namely 1D-325966494, 2D-645942075, and 7D-166300030, showed pleiotropy. Through haplotype analysis, two excellent haplotypes that significantly reduced the plant height were obtained, which were located in specific regions of chromosomes 2A and 3A. One candidate gene TraesCS2A02G457400 related to plant height was identified, and its function has not been clarified yet.