Fusarium graminearum DICER-like-dependent sRNAs are required for the suppression of host immune genes and full virulence

In filamentous fungi, gene silencing by RNA interference (RNAi) shapes many biological processes, including pathogenicity. Recently, fungal small RNAs (sRNAs) have been shown to act as effectors that disrupt activity in interacting plant hosts, thereby undermining their defence responses. We show here the devastating mycotoxin-producing ascomycete Fusarium graminearum ( Fg ) utilizes DICER-like (DCL)-dependent sRNAs target genes two Poaceae barley Hordeum vulgare , Hv and Brachypodium distachyon Bd ). identified 104 -sRNAs with sequence homology host were repressed during interactions of while they accumulated plants infected DCL double knock-out (dKO) mutant PH1- dcl1/2 . The strength expression correlated abundance corresponding -sRNA. Specifically, three tRNA-derived fragments (tRFs) targeting immunity-related Ethylene overproducer 1-like 1 HvEOL1) orthologues Arabidopsis thaliana BRI1-associated receptor kinase HvBAK1 HvSERK2 BdSERK2 was dependent on DCL. Additionally, RNA-ligase-mediated Rapid Amplification cDNA Ends (RLM-RACE) infection-specific degradation products for transcripts, consistent possibility tRFs contribute virulence via targeted silencing.