Open AccessThe APSES transcription factor LmStuA is required for sporulation, pathogenic development and effector gene expression in L eptosphaeria maculans
Author(s) -
Soyer Jessica L.,
Hamiot Audrey,
Ollivier Bénédicte,
Balesdent MarieHélène,
Rouxel Thierry,
Fudal Isabelle
Publication year - 2015
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.12249
Subject(s) - biology , leptosphaeria maculans , effector , rna interference , gene silencing , gene , gene expression , transcription factor , genetics , conidiation , mutant , microbiology and biotechnology , rna
Summary L eptosphaeria maculans causes stem canker of oilseed rape ( B rassica napus ). The APSES transcription factor StuA is a key developmental regulator of fungi, involved in morphogenesis, conidia production and also more recently described as required for secondary metabolite production and for effector gene expression in phytopathogenic fungi. We investigated the involvement of the orthologue of StuA in L . maculans , LmStuA , in morphogenesis, pathogenicity and effector gene expression. LmStuA is induced during mycelial growth and at 14 days after infection, corresponding to the development of pycnidia on oilseed rape leaves, consistent with the function of StuA described so far. We set up the functional characterization of LmStuA using an RNA interference approach. Silenced LmStuA transformants showed typical phenotypic defects of StuA mutants with altered growth in axenic culture and impaired conidia production and perithecia formation. Silencing of LmStuA abolished the pathogenicity of L . maculans on oilseed rape leaves and also resulted in a drastic decrease in expression of at least three effector genes during in planta infection, suggesting either that LmStuA regulates, directly or indirectly, the expression of several effector genes in L . maculans or that the infection stage in which effectors are expressed is not reached when LmStuA expression is silenced.