Open AccessFusarium graminearum DICER-like-dependent sRNAs are required for the suppression of host immune genes and full virulence
Author(s) -
B. Werner,
Aline Koch,
Ena Šečić,
Jonas Engelhardt,
Lukas Jelonek,
Jens Steinbrenner,
KarlHeinz Kogel
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0252365
Subject(s) - biology , brachypodium distachyon , gene , genetics , rna silencing , hordeum vulgare , rna interference , gene silencing , virulence , gene expression , rna , genome , botany , poaceae
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 gene activity in interacting plant hosts, thereby undermining their defence responses. We show here that the devastating mycotoxin-producing ascomycete Fusarium graminearum ( Fg ) utilizes DICER-like (DCL)-dependent sRNAs to target defence genes in two Poaceae hosts, barley ( Hordeum vulgare , Hv ) and Brachypodium distachyon ( Bd ). We identified 104 Fg -sRNAs with sequence homology to host genes that were repressed during interactions of Fg and Hv , while they accumulated in plants infected by the DCL double knock-out (dKO) mutant PH1- dcl1/2 . The strength of target gene expression correlated with the abundance of the corresponding Fg -sRNA. Specifically, the abundance of three tRNA-derived fragments (tRFs) targeting immunity-related Ethylene overproducer 1-like 1 ( HvEOL1) and three Poaceae orthologues of Arabidopsis thaliana BRI1-associated receptor kinase 1 ( HvBAK1 , HvSERK2 and BdSERK2 ) was dependent on fungal DCL. Additionally, RNA-ligase-mediated Rapid Amplification of cDNA Ends (RLM-RACE) identified infection-specific degradation products for the three barley gene transcripts, consistent with the possibility that tRFs contribute to fungal virulence via targeted gene silencing.