Search Results (16)

Wheat (Triticum aestivum L.) is one of the most cultivated crops in the world, but production is often affected by drought. The wheat chromosome 4A contains several quantitative trait loci (QTL) associated with drought tolerance and yield-related traits, making it a valuable target for genetic improvement. In this study, we developed near-isogenic lines (NILs) carrying qDT.4A.1, a major QTL for yield using a fast generation cycling system (FGCS) and characterized these NILs for grain yield and thousand-grain weight (TGW) under drought stress and control conditions. We identified a single nucleotide polymorphism (SNP) marker Kukri_c27037_112, which showed a consistent genotype–phenotype associations across two NIL pairs. This marker is linked to four candidate genes encoding a RING-finger E3 ubiquitin ligase, a receptor kinase, and a protein kinase family protein involved in drought stress response and pathways. In silico expression analyses revealed upregulation of these genes in grain tissue under drought conditions, supporting their potential role in grain development and yield formation during drought stress conditions. The identified SNP marker and its associated candidate genes are potential resources in marker-assisted selection and fine mapping pending further validation and functional studies. Our results provide valuable genomic resources, laying the foundation for the development of drought-tolerant wheat varieties and highlighting chromosome 4A as a key region governing drought tolerance. Full article

Wheat (Triticum aestivum L.), a crucial global food crop, provides approximately 20% of daily protein and caloric intake globally. However, its production is increasingly threatened by abiotic stressors, especially drought and salinity, which are exacerbated by climate change. These stressors adversely affect plant growth, development, and yield, necessitating the development of stress-tolerant varieties. This study investigated the role of TaUBX57, a U-box E3 ubiquitin ligase, in enhancing stress tolerance in wheat. Functional domain analysis of TaUBX57 confirmed the presence of a conserved U-box and a protein kinase domain, suggesting its involvement in protein ubiquitination and stress responses. TaUBX57-overexpressing transgenic Arabidopsis lines exhibited significantly improved germination rates, root growth, and survival under drought and salt stress conditions. TaUBX57 overexpression enhanced antioxidant enzyme activities and reduced the expression of oxidative stress markers, such as malondialdehyde. These findings highlight the potential role of TaUBX57 in modulating stress-responsive pathways and enhancing abiotic stress tolerance, offering a promising avenue for developing more resilient wheat varieties through genetic engineering. Full article

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), represents a major global threat to wheat (Triticum aestivum. L). Planting varieties with adult-plant resistance (APR) is an effective approach for long-term management of this disease. The Chinese winter wheat variety Lantian 25 exhibits moderate-to-high APR against stripe rust under field conditions. To investigate the genetic basis of APR in Lantian 25, a set of 219 F₆ recombinant inbred lines (RILs) was created from a cross between Lantian 25 (resistant parent) and Huixianhong (susceptible parent). These RILs were assessed for maximum disease severity (MDS) in Pixian of Sichuan and Qingshui of Gansu over the 2020–2021 and 2021–2022 growing seasons, resulting in data from four different environments. Genotyping was performed on these lines and their parents using the wheat Illumina 50K single-nucleotide polymorphism (SNP) arrays. Composite interval mapping (CIM) identified six quantitative trait loci (QTL), named QYr.gaas-2BS, QYr.gaas-2BL, QYr.gaas-2DS, QYr.gaas-2DL, QYr.gaas-3BS and QYr.gaas-4BL, which were consistently found across two or more environments and explained 4.8–12.0% of the phenotypic variation. Of these, QYr.gaas-2BL, QYr.gaas-2DS, and QYr.gaas-3BS overlapped with previous studies, whereas QYr.gaas-2BS, QYr.gaas-2DS, and QYr.gaas-4BL might be novel. All the resistance alleles for these QTL originated from Lantian 25. Furthermore, four kompetitive allele-specific PCR (KASP) markers, Kasp_2BS_YR (QYr.gaas-2BS), Kasp_2BL_YR (QYr.gaas-2BL), Kasp_2DS_YR (QYr.gaas-2DS) and Kasp_2DL_YR (QYr.gaas-2DL), were developed and validated in 110 wheat diverse accessions. Additionally, we identified seven candidate genes linked to stripe rust resistance, including disease resistance protein RGA2, serine/threonine-protein kinase, F-box family proteins, leucine-rich repeat family proteins, and E3 ubiquitin-protein ligases. These QTL, along with their associated KASP markers, hold promise for enhancing stripe rust resistance in wheat breeding programs. Full article

Wheat (Triticum aestivum) is one of the most important cereal crops globally, with significant economic value. The Arabidopsis Tóxicos en Levadura (ATL) gene family, which comprises members of ubiquitin ligase enzymes (E3s), functions in substrate protein tagging during ubiquitin-mediated protein modification. Recent studies have demonstrated its involvement in stress responses. However, the ATL gene family in wheat remains poorly characterized. This study aimed to identify the members of the ATL gene family in wheat and investigate their roles under salt stress. We identified 334 TaATL genes in the wheat genome, all of which contain either RING-H2, RING U-box, or RAD18 superfamily domains, exhibiting a remarkably low proportion of intron-containing genes. The Ka/Ks (non-synonymous to synonymous substitution rate) analysis and cis-acting element analysis of the TaATL gene family indicate that its sequences are highly conserved and functionally constrained, suggesting that it may participate in abiotic stress responses through the ABA, MeJA, and MYB signaling pathways. Both RNA-seq analysis and RT-qPCR data demonstrated that the expression levels of the TaATL gene family were significantly upregulated under stress conditions, indicating their crucial roles in stress responses. This study demonstrates that the targeted regulation of stress-responsive signaling pathways mediated by superior TaATL gene family members can effectively enhance wheat salt tolerance, thereby providing a viable strategy for the development of high-yielding cultivars adapted to saline agricultural ecosystems. Full article

Waterlogging stress causes substantial destruction to plant growth and production under climatic fluctuations globally. Plants hormones have been widely explored in numerous crops, displaying an imperative role in crop defense and growth mechanism. However, there is a paucity of research on the subject of plant hormones regulating waterlogging stress responses in wheat crop. In this study, we clarified the role of 6-BA in waterlogging stress through inducing phenylpropanoid biosynthesis in wheat. The application of 6-BA (6-benzyladenine) enhanced the growth and development of wheat plants under waterlogging stress, which was accompanied by reduced electrolyte leakage, high chlorophyll, and soluble sugar content. ROS scavenging was also enhanced by 6-BA, resulting in reduced MDA and H₂O₂ accumulation and amplified antioxidant enzyme activities. Additionally, under the effect of 6-BA, the acceleration of lignin content and accumulation in the cell walls of wheat tissues, along with the activation of PAL (phenylalanine ammonia lyase), TAL (tyrosine ammonia lyase), and 4CL (4-hydroxycinnamate CoA ligase) activities and the increase in the level of transcription of the TaPAL and Ta4CL genes, were observed under waterlogging stress. Also, 6-BA improved the root growth system under waterlogging stress conditions. Further qPCR analysis revealed increased auxin signaling (TaPR1) in 6-BA-treated plants under waterlogging stress that was consistent with the induction of endogenous IAA hormone content under waterlogging stress conditions. Here, 6-BA also reduced yield loss, as compared to control plants. Thus, the obtained data suggested that, under the application of 6-BA, phenylpropanoid metabolism (i.e., lignin) was stimulated, playing a significant role in reducing the negative effects of waterlogging stress on yield, as evinced by the improved plant growth parameters. Full article

E3 ubiquitin ligases play a pivotal role in ubiquitination, a crucial post-translational modification process. Anaphase-promoting complex (APC), a large cullin-RING E3 ubiquitin ligase, regulates the unidirectional progression of the cell cycle by ubiquitinating specific target proteins and triggering plant immune responses. Several E3 ubiquitin ligases have been identified owing to advancements in sequencing and annotation of the wheat genome. However, the types and functions of APC E3 ubiquitin ligases in wheat have not been reported. This study identified 14 members of the APC gene family in the wheat genome and divided them into three subgroups (CCS52B, CCS52A, and CDC20) to better understand their functions. Promoter sequence analysis revealed the presence of several cis-acting elements related to hormone and stress responses in the APC E3 ubiquitin ligases in wheat. All identified APC E3 ubiquitin ligase family members were highly expressed in the leaves, and the expression of most genes was induced by the application of methyl jasmonate (MeJA). In addition, the APC gene family in wheat may play a role in plant defense mechanisms. This study comprehensively analyzes APC genes in wheat, laying the groundwork for future research on the function of APC genes in response to viral infections and expanding our understanding of wheat immunity mechanisms. Full article

Drought poses a significant challenge to global wheat production, and the application of exogenous phytohormones offers a convenient approach to enhancing drought tolerance of wheat. However, little is known about the molecular mechanism by which strigolactones (SLs), newly discovered phytohormones, alleviate drought stress in wheat. Therefore, this study is aimed at elucidating the physiological and molecular mechanisms operating in wheat and gaining insights into the specific role of SLs in ameliorating responses to the stress. The results showed that SLs application upregulated the expression of genes associated with the antioxidant defense system (Fe/Mn-SOD, PER1, PER22, SPC4, CAT2, APX1, APX7, GSTU6, GST4, GOR, GRXC1, and GRXC15), chlorophyll biogenesis (CHLH, and CPX), light-harvesting chlorophyll A-B binding proteins (WHAB1.6, and LHC Ib-21), electron transfer (PNSL2), E3 ubiquitin-protein ligase (BB, CHIP, and RHY1A), heat stress transcription factor (HSFA1, HSFA4D, and HSFC2B), heat shock proteins (HSP23.2, HSP16.9A, HSP17.9A, HSP21, HSP70, HSP70-16, HSP70-17, HSP70-8, HSP90-5, and HSP90-6), DnaJ family members (ATJ1, ATJ3, and DJA6), as well as other chaperones (BAG1, CIP73, CIPB1, and CPN60I). but the expression level of genes involved in chlorophyll degradation (SGR, NOL, PPH, PAO, TIC55, and PTC52) as well as photorespiration (AGT2) was found to be downregulated by SLs priming. As a result, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced, and chlorophyll content and photosynthetic rate were increased, which indicated the alleviation of drought stress in wheat. These findings demonstrated that SLs alleviate drought stress by promoting photosynthesis through enhancing chlorophyll levels, and by facilitating ROS scavenging through modulation of the antioxidant system. The study advances understandings of the molecular mechanism underlying SLs-mediated drought alleviation and provides valuable insights for implementing sustainable farming practice under water restriction. Full article

Wheat (Triticum aestivum L.) cultivation has been globally restricted by many plant viruses such as the Wheat streak mosaic virus (WSMV), Barley stripe mosaic virus (BSMV), and Brome mosaic virus (BMV). Herein, the transcriptome of wheat was in silico analyzed under mono- (WSMV, BSMV, or BMV), bi- (BMV&BSMV, BMV&WSMV, and BSMV&WSMV), and tripartite (WSMV, BSMV, and BMV) infections using the RNA-seq technique. Total numbers of 1616/270, 5243/690 and 5589/2183 differentially expressed genes (DEGs) were up/down-regulated during the bipartite infection of BMV&BSMV, BMV&WSMV and BSMV&WSMV, respectively, while the tripartite infection resulted in the up/down-regulation of 6110/2424 DEGs. The NAC and bHLH were the most commonly presented transcription factor (TF) families in WSMV, BMV, and BSMV infection, while C2H2, bHLH, and NAC were the TF families involved in BMV&WSMV, BMV&BSMV, and BSMV&WSMV infections, respectively. The RLK-Pelle_DLSV was the most commonly expressed protein kinase (PK) family in all infection patterns. Promoter analysis showed that the motifs involved in gene expression, CUL4 RING ubiquitin ligase complex, stress response, brassinosteroid response, and energy-related pathways were significantly induced in wheat plants under bipartite infections. The gene expression network analysis showed that a defense-related gene, i.e., allene oxide synthase (AOS) gene, serves as a crucial hub in tripartite infections. Full article

Plant U-box E3 ubiquitin ligase (PUB) is involved in various environmental stress conditions. However, the molecular mechanism of U-box proteins in response to abiotic stress in wheat remains unknown. In this study, two U-box E3 ligase genes (TaPUB2 and TaPUB3), which are highly expressed in response to adverse abiotic stresses, were isolated from common wheat, and their cellular functions were characterized under drought stress. Transient expression assay revealed that TaPUB2 was localized in the cytoplasm and Golgi apparatus, whereas TaPUB3 was expressed only in the Golgi apparatus in wheat protoplasts. Additionally, TaPUB2 and TaPUB3 underwent self-ubiquitination. Moreover, TaPUB2/TaPUB3 heterodimer was identified in yeast and the cytoplasm of wheat protoplasts using a pull-down assay and bimolecular fluorescence complementation analysis. Heterogeneous overexpression of TaPUB2 and TaPUB3 conferred tolerance to drought stress. Taken together, these results implied that the heterodimeric form of U-box E3 ubiquitin ligases (TaPUB2/TaPUB3) responded to abiotic stress and roles as a positive regulator of drought stress tolerance. Full article

Wheat pre-harvest sprouting (PHS) causes serious losses in wheat yield. In this study, precise mapping was carried out in the chromosome segment substitution lines (CSSL) F₂ population generated by a direct cross of Zhoumai 18 (PHS-sensitive) and Aegilops tauschii accession T093 (highly PHS-resistant). Three Ae. tauschii-derived quantitative trait loci (QTLs), QDor.3D.1, QDor.3D.2, and QDor.3D.3, were detected on chromosome 3DL using four simple sequence repeats (SSR) markers and 10 developed Kompetitive allele-specific PCR (KASP) markers. Alongside these QTL results, the RNA-Seq and qRT-PCR analysis revealed expression levels of TraesCS3D01G466100 in the QDor.3D.2 region that were significantly higher in CSSLs 495 than in Zhoumai 18 during the seed imbibition treatment. The cDNA sequencing results of TraesCS3D01G466100 showed two single nucleotide polymorphisms (SNPs), resulting in two changed amino acid substitutions between Zhoumai 18 and line 495, and the 148 nt amino acid substitution of TraesCS3D01G466100, derived from Ae. tauschii T093, which may play an important role in the functioning of ubiquitin ligase enzymes 3 (E3) according to the homology protein analysis, which could lead to differential PHS-resistance phenotypes. Taken together, our results may foster a better understanding of the mechanism of PHS resistance and are potentially valuable for marker-assisted selection in practical wheat breeding efforts. Full article

FBX proteins are subunits of the SCF complex (Skp1–cullin–FBX) belonging to the E3 ligase family, which is involved in the ubiquitin–proteasome 26S (UPS) pathway responsible for the post-translational protein turnover. By targeting, in a selective manner, key regulatory proteins for ubiquitination and 26S proteasome degradation, FBX proteins play a major role in plant responses to diverse developmental and stress conditions. Although studies on the genomic organization of the FBX gene family in various species have been reported, knowledge related to bread wheat (Triticum aestivum) is scarce and needs to be broadened. Using the latest assembly of the wheat genome, we identified 3670 TaFBX genes distributed non-homogeneously within the three subgenomes (A, B and D) and between the 21 chromosomes, establishing it as one of the richest gene families among plant species. Based on the presence of the five different chromosomal regions previously identified, the present study focused on the genomic distribution of the TaFBX family and the identification of differentially expressed genes during the embryogenesis stages and in response to heat and drought stress. Most of the time, when comparing the expected number of genes (taking into account the formal gene distribution on the entire wheat genome), the TaFBX family harbors a different pattern at the various stratum of observation (subgenome, chromosome, chromosomal regions). We report here that the local gene expansion of the TaFBX family must be the consequence of multiple and complex events, including tandem and small-scale duplications. Regarding the differentially expressed TaFBX genes, while the majority of the genes are localized in the distal chromosomal regions (R1 and R3), differentially expressed genes are more present in the interstitial regions (R2a and R2b) than expected, which could be an indication of the preservation of major genes in those specific chromosomal regions. Full article

U-box E3 ligase genes play specific roles in protein degradation by post-translational modification in plant signaling pathways, developmental stages, and stress responses; however, little is known about U-box E3 genes in wheat. We identified 213 U-box E3 genes in wheat based on U-box and other functional domains in their genome sequences. The U-box E3 genes were distributed among 21 chromosomes and most showed high sequence homology with homoeologous U-box E3 genes. Synteny analysis of wheat U-box E3 genes was conducted with other plant species such as Brachypodium distachyon, barley, rice, Triricum uratu, and Aegilops tauschii. A total of 209 RNA-seq samples representing 22 tissue types, from grain, root, leaf, and spike samples across multiple time points, were analyzed for clustering of U-box E3 gene expression during developmental stages, and the genes responded differently in various tissues and developmental stages. In addition, expression analysis of U-box E3 genes under abiotic stress, including drought, heat, and both heat and drought, and cold conditions, was conducted to provide information on U-box E3 gene expression under specific stress conditions. This analysis of U-box E3 genes could provide valuable information to elucidate biological functions for a better understanding of U-box E3 genes in wheat. Full article

Kernel weight and shape-related traits are inherited stably and increase wheat yield. Narrow genetic diversity limits the progress of wheat breeding. Here, we evaluated kernel weight and shape-related traits and applied genome-wide association analysis to a panel of wheat multiple synthetic derivative (MSD) lines. The MSD lines harbored genomic fragments from Aegilops tauschii. These materials were grown under optimum conditions in Japan, as well as under heat and combined heat–drought conditions in Sudan. We aimed to explore useful QTLs for kernel weight and shape-related traits under stress conditions. These can be useful for enhancing yield under stress conditions. MSD lines possessed remarkable genetic variation for all traits under all conditions, and some lines showed better performance than the background parent Norin 61. We identified 82 marker trait associations (MTAs) under the three conditions; most of them originated from the D genome. All of the favorable alleles originated from Ae. tauschii. For the first time, we identified markers on chromosome 5D associated with a candidate gene encoding a RING-type E3 ubiquitin–protein ligase and expected to have a role in regulating wheat seed size. Our study provides important knowledge for the improvement of wheat yield under optimum and stress conditions. The results emphasize the importance of Ae. tauschii as a gene reservoir for wheat breeding. Full article

Previously, studies on RING-type E3 ubiquitin ligases in cereals were preferentially focused on GW2 genes primarily controlling seed parameters in rice and wheat. Here we report cloning two HvYrg genes from barley that share significant homology with rice GW2 gene. In antisense genotypes efficiency of gene silencing varied between genes and transgenic lines: ASHvYrg1: 30–50% and ASHvYrg2: 20–27%. Reduced activity of both genes altered shoot system with increasing number of side shoots. Changes in leaf width, weight, or plant weight and height reached significant levels in some transgenic lines. Lowering expression of the two barley HvYrg genes caused opposite responses in spike development. Plants with ASHvYrg1 gene construct showed earlier heading time and prolonged grain-filling period, while plants from ASHvYrg2 genotype flowered in delay. Digital imaging of root development revealed that down-regulation of HvYrg1 gene variant stimulated root growth, while ASHvYrg2 plants developed reduced root system. Comparison of seed parameters indicated an increase in thousand grain weight accompanied with longer and wider seed morphology. In summary we conclude that in contrast to inhibition of GW2 genes in rice and wheat plants, down-regulation of the barely HvYrg genes caused substantial changes in vegetative organs in addition to alteration of seed parameters. Full article

Wheat powdery mildew (Pm), caused by Blumeria graminis f. sp. tritici (Bgt), is a prevalent fungal disease. The diploid wheat relative Haynaldia villosa (H. villosa) showed broad-spectrum resistance (BSR) to Pm. A previous study reported an E3 ligase gene, CMPG1-V from H. villosa, showing BSR to Pm. To elucidate the regulatory network mediated by CMPG1-V, in this study, gene expression profiling of CMPG1-V transgenic plant (CMPG1-V_OE) and its receptor Yangmai 158 was analyzed and compared after Bgt inoculation at four infection stages. GO and KEGG analysis revealed obvious reprogramming of SA and ABA signaling, starch/sucrose metabolism, and photosynthesis in CMPG1-V_OE, compared with those in Yangmai 158. Transcripts of SA synthesis genes SARD1 and UGT, signaling factors TGA and PRs, and SnRKs in ABA signaling were specifically upregulated in CMPG1-V_OE rather than Yangmai 158. Transcripts of LHCII in photosynthesis, GLUC and TPP in starch/sucrose metabolism were also induced distinctly in CMPG1-V_OE. WGCNA analysis showed crucial regulatory candidates of CMPG1-V, involving serine/threonine-protein kinase in phosphorylation, glucosyltransferase in flavonoid biosynthesis, defense factor WRKYs, and peroxidase in oxidative stress. Our results facilitate the deciphering of the resistant regulatory network of CMPG1-V and the identification of key candidates which might be employed in breeding programs. Full article