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An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen
Author(s) -
Tollot Marie,
Wong Sak Hoi Joanne,
Van Tuinen Diederik,
Arnould Christine,
Chatagnier Odile,
Dumas Bernard,
GianinazziPearson Vivienne,
Seddas Pascale M. A.
Publication year - 2009
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2008.02696.x
Subject(s) - biology , colletotrichum lindemuthianum , medicago truncatula , microbiology and biotechnology , mutant , colletotrichum , complementation , botany , gene , ralstonia solanacearum , fungus , hypha , pathogen , infectivity , genetics , symbiosis , bacteria , virus , cultivar
Summary• Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. • Using degenerated primers and rapid amplification of cDNA ends, we isolated the full‐length cDNA of an STE12 ‐like gene, GintSTE , from Glomus intraradices and profiled GintSTE expression by real‐time and in situ RT‐PCR. GintSTE activity and function were investigated by heterologous complementation of a yeast ste12Δ mutant and a Colletotrichum lindemuthianum clste12Δ mutant. • Sequence data indicate that GintSTE is similar to STE12 from hemibiotrophic plant pathogens, especially Colletotrichum spp. Introduction of GintSTE into a noninvasive mutant of C. lindemuthianum restored fungal infectivity of plant tissues. GintSTE expression was specifically localized in extraradicular fungal structures and was up‐regulated when G. intraradices penetrated roots of wild‐type Medicago truncatula as compared with an incompatible mutant. • Results suggest a possible role for GintSTE in early steps of root penetration by AM fungi, and that pathogenic and symbiotic fungi may share common regulatory mechanisms for invasion of plant tissues.