Alternative transcription start site selection in Mr-OPY2 controls lifestyle transitions in the fungus Metarhizium robertsii

• DOI: 10.1038/s41467-017-01756-1
• Publication Date: 2017-11-12T22:30:39Z
• Authors: Na Guo; Ying Qian; Qiangqiang Zhang; Xiaoxuan Chen; Guohong Zeng; Xing Zhang; Wubing Mi; Chuan Xu; Raymond J. St. Leger; Weiguo Fang
• Keywords: Metarhizium; Entomopathogenic fungus; Pathogenic fungus; Transcription

Abstract Metarhizium robertsii is a versatile fungus with saprophytic, plant symbiotic and insect pathogenic lifestyle options. Here we show that M. mediates the saprophyte-to-insect pathogen transition through modulation of expression membrane protein, Mr-OPY2. Abundant Mr-OPY2 protein initiates appressorium formation, prerequisite for infection, whereas reduced production elicits saprophytic growth conidiation. The precise regulation achieved via alternative transcription start sites. During growth, single long transcript produced small upstream open reading frames in its 5′ untranslated region. Increased on host cuticle by variant lacking frame would otherwise inhibit translation RNA-seq qRT-PCR analyses negative regulator factor demonstrate necessary appressorial formation. These findings provide insights into mechanisms regulating fungal transitions.