A Glutathione S-Transferase from Confers Resistance to Fusarium Head Blight in Wheat.

Fusarium head blight (FHB), mainly incited by , has caused great losses in grain yield and quality of wheat globally. , a major gene from 7E chromosome of , confers broad resistance to multiple species in wheat and has recently been cloned and identified as encoding a glutathione S-transferase (). However, some recent reports raised doubt about whether is the causal gene of . To resolve the discrepancy and validate the gene function of in wheat, we phenotyped near-isogenic lines (Jimai22- versus Jimai22) and overexpressed lines for FHB resistance. Jimai22- showed significantly higher FHB resistance with a lower percentage of symptomatic spikelets, -damaged kernels, and deoxynivalenol content than susceptible Jimai22 in three experiments. All the positive transgenic lines driven by either the maize ubiquitin promoter or its native promoter with high gene expression in the wheat cultivar 'Fielder' showed high FHB resistance. Only one maize ubiquitin promoter-driven transgenic line showed low expression and similar susceptibility to Fielder, suggesting that high expression confers resistance to FHB. Knockout of in the Jimai22- line using CRISPR-Cas9-based gene editing showed significantly higher FHB susceptibility compared with the nonedited control plants. Therefore, we confirmed as the causal gene of for FHB resistance. Considering its major effect on FHB resistance, pyramiding with other quantitative trait loci has a great potential to create highly FHB-resistant wheat cultivars.