start-ver=1.4 cd-journal=joma no-vol=104 cd-vols= no-issue=4 article-no= start-page=995 end-page=1008 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20201120 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=BdWRKY38 is required for the incompatible interaction of Brachypodium distachyon with the necrotrophic fungus Rhizoctonia solani en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rhizoctonia solani is a soil‐borne necrotrophic fungus that causes sheath blight in grasses. The basal resistance of compatible interactions between R. solani and rice is known to be modulated by some WRKY transcription factors (TFs). However, genes and defense responses involved in incompatible interaction with R. solani remain unexplored, because no such interactions are known in any host plants. Recently, we demonstrated that Bd3‐1, an accession of the model grass Brachypodium distachyon, is resistant to R. solani and, upon inoculation with the fungus, undergoes rapid induction of genes responsive to the phytohormone salicylic acid (SA) that encode the WRKY TFs BdWRKY38 and BdWRKY44. Here, we show that endogenous SA and these WRKY TFs positively regulate this accession‐specific R. solani resistance. In contrast to a susceptible accession (Bd21), the infection process in the resistant accessions Bd3‐1 and Tek‐3 was suppressed at early stages before the development of fungal biomass and infection machinery. A comparative transcriptome analysis during pathogen infection revealed that putative WRKY‐dependent defense genes were induced faster in the resistant accessions than in Bd21. A gene regulatory network (GRN) analysis based on the transcriptome dataset demonstrated that BdWRKY38 was a GRN hub connected to many target genes specifically in resistant accessions, whereas BdWRKY44 was shared in the GRNs of all three accessions. Moreover, overexpression of BdWRKY38 increased R. solani resistance in Bd21. Our findings demonstrate that these resistant accessions can activate an incompatible host response to R. solani, and BdWRKY38 regulates this response by mediating SA signaling. en-copyright= kn-copyright= en-aut-name=KouzaiYusuke en-aut-sei=Kouzai en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ShimizuMinami en-aut-sei=Shimizu en-aut-mei=Minami kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=InoueKomaki en-aut-sei=Inoue en-aut-mei=Komaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=Uehara‐YamaguchiYukiko en-aut-sei=Uehara‐Yamaguchi en-aut-mei=Yukiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakahagiKotaro en-aut-sei=Takahagi en-aut-mei=Kotaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakayamaRisa en-aut-sei=Nakayama en-aut-mei=Risa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=MatsuuraTakakazu en-aut-sei=Matsuura en-aut-mei=Takakazu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=MoriIzumi C. en-aut-sei=Mori en-aut-mei=Izumi C. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=HirayamaTakashi en-aut-sei=Hirayama en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=AbdelsalamSobhy S. H. en-aut-sei=Abdelsalam en-aut-mei=Sobhy S. H. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=NoutoshiYoshiteru en-aut-sei=Noutoshi en-aut-mei=Yoshiteru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MochidaKeiichi en-aut-sei=Mochida en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= affil-num=1 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=2 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=3 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=4 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=5 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=6 en-affil=Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science kn-affil= affil-num=7 en-affil=Institute of Plant Science and Resources (IPSR), Okayama University kn-affil= affil-num=8 en-affil=Institute of Plant Science and Resources (IPSR), Okayama University kn-affil= affil-num=9 en-affil=Institute of Plant Science and Resources (IPSR), Okayama University kn-affil= affil-num=10 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=11 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=12 en-affil=Institute of Plant Science and Resources (IPSR), Okayama University kn-affil= en-keyword=Brachypodium distachyon kn-keyword=Brachypodium distachyon en-keyword=disease resistance kn-keyword=disease resistance en-keyword=Rhizoctonia solani kn-keyword=Rhizoctonia solani en-keyword=salicylic acid kn-keyword=salicylic acid en-keyword=incompatible interaction kn-keyword=incompatible interaction en-keyword=sheath blight kn-keyword=sheath blight en-keyword=transcriptome kn-keyword=transcriptome en-keyword=WRKY kn-keyword=WRKY END