
The β‐1,3‐glucanosyltransferases (Gels) affect the structure of the rice blast fungal cell wall during appressorium‐mediated plant infection
Author(s) -
Samalova Marketa,
Mélida Hugo,
Vilaplana Francisco,
Bulone Vincent,
Soanes Darren M.,
Talbot Nicholas J.,
Gurr Sarah J.
Publication year - 2017
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.12659
Subject(s) - biology , appressorium , cell wall , mutant , spore , phenotype , fungal protein , microbiology and biotechnology , cell , glycoside hydrolase , fungus , wild type , gene , biochemistry , botany
The fungal wall is pivotal for cell shape and function, and in interfacial protection during host infection and environmental challenge. Here, we provide the first description of the carbohydrate composition and structure of the cell wall of the rice blast fungus Magnaporthe oryzae . We focus on the family of glucan elongation proteins (Gels) and characterize five putative β‐1,3‐glucan glucanosyltransferases that each carry the Glycoside Hydrolase 72 signature. We generated targeted deletion mutants of all Gel isoforms, that is, the GH72 + , which carry a putative carbohydrate‐binding module, and the GH72 − Gels, without this motif. We reveal that M. oryzae GH72 + GEL s are expressed in spores and during both infective and vegetative growth, but each individual Gel enzymes are dispensable for pathogenicity. Further, we demonstrated that a Δgel1Δgel3Δgel4 null mutant has a modified cell wall in which 1,3‐glucans have a higher degree of polymerization and are less branched than the wild‐type strain. The mutant showed significant differences in global patterns of gene expression, a hyper‐branching phenotype and no sporulation, and thus was unable to cause rice blast lesions (except via wounded tissues). We conclude that Gel proteins play significant roles in structural modification of the fungal cell wall during appressorium‐mediated plant infection.