Open AccessInfection cushions of Fusarium graminearum are fungal arsenals for wheat infection
Author(s) -
Mentges Michael,
Glasenapp Anika,
Boenisch Marike,
Malz Sascha,
Henrissat Bernard,
Frandsen Rasmus J.N.,
Güldener Ulrich,
Münsterkötter Martin,
Bormann Jörg,
Lebrun MarcHenri,
Schäfer Wilhelm,
MartinezRocha Ana Lilia
Publication year - 2020
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12960
Subject(s) - biology , virulence , hypha , fusarium , microbiology and biotechnology , gene , fungus , transcriptome , mycelium , mycotoxin , bipolaris , pathogenic fungus , laser capture microdissection , fungal protein , genetics , botany , gene expression , mutant
Fusarium graminearum is one of the most destructive plant pathogens worldwide, causing fusarium head blight (FHB) on cereals. F . graminearum colonizes wheat plant surfaces with specialized unbranched hyphae called runner hyphae (RH), which develop multicelled complex appressoria called infection cushions (IC). IC generate multiple penetration sites, allowing the fungus to enter the plant cuticle. Complex infection structures are typical for several economically important plant pathogens, yet with unknown molecular basis. In this study, RH and IC formed on the surface of wheat paleae were isolated by laser capture microdissection. RNA‐Seq‐based transcriptomic analyses were performed on RH and IC and compared to mycelium grown in complete medium (MY). Both RH and IC displayed a high number of infection up‐regulated genes (982), encoding, among others, carbohydrate‐active enzymes (CAZymes: 140), putative effectors (PE: 88), or secondary metabolism gene clusters (SMC: 12 of 67 clusters). RH specifically up‐regulated one SMC corresponding to aurofusarin biosynthesis, a broad activity antibiotic. IC specifically up‐regulated 248 genes encoding mostly putative virulence factors such as 7 SMC, including the mycotoxin deoxynivalenol and the newly identified fusaoctaxin A, 33 PE, and 42 CAZymes. Furthermore, we studied selected candidate virulence factors using cellular biology and reverse genetics. Hence, our results demonstrate that IC accumulate an arsenal of proven and putative virulence factors to facilitate the invasion of epidermal cells.