An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen

作者：Tollot Marie; Hoi Joanne Wong Sak; van Tuinen Diederik; Arnould Christine; Chatagnier Odile; Dumas Bernard; Gianinazzi Pearson Vivienne; Seddas Pascale M A^*

来源：New Phytologist, 2009, 181(3): 693-707.

DOI：10.1111/j.1469-8137.2008.02696.x

• Glomeromycota
• hemibiotrophic pathogen
• host penetration
• mycorrhiza
• STE12
• transcription factor

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 ste12 Delta mutant and a Colletotrichum lindemuthianum clste12 Delta 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.
New Phytologist (2009) 181: 693-707 doi: 10.1111/j.1469-8137.2008.02696.x.

• 出版日期2009