Fumarylacetoacetate hydrolase targeted by a Fusarium graminearum effector positively regulates wheat FHB resistance and yield and promotes heading
Fusarium head blight (FHB), caused by Fusarium graminearum is a devastating disease that affects global wheat production. F. graminearum encodes many effector proteins; however, its virulence mechanisms are poorly understood. In this study, we identified a secretory effector candidate protein (FgEC10) that is essential for the virulence of F. graminearum and suppresses the basal immune response. FgEC10 interacted strongly with wheat fumarylacetoacetate hydrolase (TaFAH) and accelerated its degradation via the 26S proteasome pathway. In addition, we showed that TaFAH interacted with TaPSMD, an important component of the 26S proteasome and that FgEC10 enhanced the interaction between TaFAH and TaPSMD. RNA silencing or overexpression of TaFAH in wheat plants showed that TaFAH positively regulated wheat FHB resistance, heading period, and grain yield. Transcriptomic analysis revealed that TaFAH promoted the expression of genes associated with disease resistance and the heading period. Metabolomic analysis revealed that overexpression of TaFAH increased the levels of several amino acids that inhibited F. graminearum growth and enhanced wheat resistance to FHB. Collectively, our study reveals a novel pathogenic mechanism and provides a valuable genetic resource for improving FHB resistance and grain yield in wheat. Overall design: To investigate the function wheat TaFAH in the regulation of wheat growth and resistance to Fusarium graminearum, we generated transgenic wheat plants overexpressing or RNAi silencing TaFAH gene. We then performed gene expression profiling analysis using data obtained from RNA-seq of these transgenic plants.