Fusarium head blight (FHB), a devastating disease in wheat worldwide, results in yield loses and mycotoxin, such as deoxynivalenol (DON), accumulation in infected grains. DON also facilitates the pathogen colonization and spread of FHB symptoms during disease development. UDP-glycosyltransferase enzymes (UGTs) are known to contribute to detoxification and enhance FHB resistance by glycosylating DON into DON-3-glucoside (D3G) in wheat. However, a comprehensive investigation of wheat (Triticum aestivum) UGT genes is still lacking. In this study, we carried out a genome-wide analysis of family-1 UDP glycosyltransferases in wheat based on the PSPG conserved box that resulted in the identification of 179 putative UGT genes. The identified genes were clustered into 16 major phylogenetic groups with a lack of phylogenetic group K. The UGT genes were invariably distributed among all the chromosomes of the 3 genomes. At least 10 intron insertion events were found in the UGT sequences, where intron 4 was observed as the most conserved intron. The expression analysis of the wheat UGT genes using both online microarray data and quantitative real-time PCR verification suggested the distinct role of UGT genes in different tissues and developmental stages. The expression of many UGT genes was up-regulated after Fusarium graminearum inoculation, and six of the genes were further verified by RT-qPCR. We identified 179 UGT genes from wheat using the available sequenced wheat genome. This study provides useful insight into the phylogenetic structure, distribution, and expression patterns of family-1 UDP glycosyltransferases in wheat. The results also offer a foundation for future work aimed at elucidating the molecular mechanisms underlying the resistance to FHB and DON accumulation.

Fusarium head blight (FHB), a devastating wheat disease, results in loss of yield and production of mycotoxins including deoxynivalenol (DON) in infected grains. DON is harmful to human and animal health and facilitates the spread of FHB symptoms. Its conversion into DON-3-glucoside (D3G) by UDP-glycosyltransferases (UGTs) is correlated with FHB resistance, and only few gene members in wheat have been investigated. Here, Fusarium graminearum and DON-induced TaUGT6 expression in the resistant cultivar Sumai 3 was cloned and characterized. TaUGT6::GFP was subcellularly located throughout cells. Purified TaUGT6 protein could convert DON into D3G to some extent in vitro. Transformation of TaUGT6 into Arabidopsis increased root tolerance when grown on agar plates containing DON. Furthermore, TaUGT6 overexpression in wheat showed improved resistance to Fusarium spread after F. graminearum inoculation. Overall, this study provides useful insight into a novel UGT gene for FHB resistance in wheat.

Fusarium head blight (FHB) caused primarily by Fusarium graminearum is a devastating disease of wheat worldwide. FHB infection not only leads to serious yield lossses, but also results in critical health issues because of mycotoxin contamination, especially deoxynivalenol (DON). Novel approaches are therefore urgently required to combat FHB, due to the development of fungicide resistance in F. graminearum and the unavailability of FHB‐resistant wheat cultivars. We here evaluated the use of host‐induced gene silencing (HIGS) in transgenic wheat plants as a strategy to control FHB by simultaneously silencing multiple genes of F. graminearum. A chimeric hairpin RNA interference (RNAi) construct targeting to the pathogenicity and essential genes including FgSGE1, FgSTE12, and FgPP1 was able to simultaneously reduce target gene expression and caused defects of growth, conidiation and virulence in transgenic F. graminearum strains. Two transgenic wheat lines of T2 and T3 generations expressing the RNAi construct in a susceptible wheat cultivar Yangmai16 displayed high levels of stable and consistent resistance to F. graminearum, and reduced DON production in wheat. Development of fungal infection structures was dramatically impaired in the transgenic wheat lines. Small RNA sequencing confirmed the presence of small interfering RNAs specific to the three targeted fungal genes in the transgenic wheat plants, which is consistent with the reduced expression of the target genes in the invading fungus. These results demonstrate that HIGS targeting multiple genes of the fungus is effective and can be used as an alternative approach for developing FHB‐resistant crops.

Fusarium head blight (FHB) is a destructive fungal disease in wheat worldwide. Efforts have been carried out to combat this disease, and the pore-forming toxin-like (PFT) gene at the quantitative trait locus (QTL) Fhb1 was isolated and found to confer resistance to FHB in Sumai 3. In this study, we characterized PFT in 348 wheat accessions. Four haplotypes of PFT were identified. The wild haplotype of PFT had higher resistance than other haplotypes and explained 13.8% of phenotypic variation in FHB resistance by association analysis. PFT was highly expressed during early flowering and increased after Fusarium graminearum treatment in Sumai 3. Analysis of the 5′ flanking sequence of PFT predicted that the cis elements of the PFT promoter were related to hormones and biological defense responses. However, PFT existed not only in the FHB-resistant accessions but also in some susceptible accessions. These results suggested that FHB resistance in a diverse range of wheat genotypes is partially conditioned by PFT. The profiling of FHB resistance and the PFT locus in this large collection of wheat germplasm may prove helpful for incorporating FHB resistance into wheat breeding programs, although more work is needed to reveal the exact role of the QTL Fhb1 in conferring resistance to fungal spread.

Wall-associated kinases (WAKs) are important receptor-like proteins that play major roles in plant defense against pathogens. Fusarium head blight (FHB), one of the most widespread and devastating crop diseases, reduces wheat yield and leads to quality deterioration. Although WAK gene families have been studied in many plants, systematic research on bread wheat (Triticum aestivum) and its role in FHB resistance, in particular, is lacking. In this study, we identified and characterized 320 genes of the TaWAK family in wheat distributed across all chromosomes except 4B and divided them into three phylogenetic groups. Duplication and synteny analyses provided valuable information on the evolutionary characteristics of the TaWAK genes. The gene expression pattern analysis suggested that TaWAK genes play diverse roles in plant biological processes and that at least 30 genes may be involved in the response to Fusarium infection in wheat spikes, with most of the genes contributing to pectin- and chitin-induced defense pathways. Furthermore, 45 TaWAK genes were identified within 17 hcmQTLs that are related to wheat FHB resistance. Our findings provide potential candidate genes for improving FHB resistance and insights into the future functional analysis of TaWAK genes in wheat.