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Genome sequence of the insect pathogenic fungus Cordyceps militaris, a valued traditional chinese medicine

Peng Zheng1, Yongliang Xia1, Guohua Xiao1, Chenghui Xiong1, Xiao Hu1, Siwei Zhang1, Huajun Zheng2, Yin Huang2, Yan Zhou2, Shengyue Wang2, Guo-Ping Zhao12, Xingzhong Liu3, Raymond J St Leger4 and Chengshu Wang1*

Author Affiliations

1 Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China

2 Chinese National Human Genome Center at Shanghai, 250 Bibo Road, Shanghai 201203, China

3 Institute of Microbiology, Chinese Academy of Sciences, 1 West Beichen Road, Beijing 100101, China

4 Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, Maryland 20742, USA

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Genome Biology 2011, 12:R116  doi:10.1186/gb-2011-12-11-r116

Published: 23 November 2011

Abstract

Background

Species in the ascomycete fungal genus Cordyceps have been proposed to be the teleomorphs of Metarhizium species. The latter have been widely used as insect biocontrol agents. Cordyceps species are highly prized for use in traditional Chinese medicines, but the genes responsible for biosynthesis of bioactive components, insect pathogenicity and the control of sexuality and fruiting have not been determined.

Results

Here, we report the genome sequence of the type species Cordyceps militaris. Phylogenomic analysis suggests that different species in the Cordyceps/Metarhizium genera have evolved into insect pathogens independently of each other, and that their similar large secretomes and gene family expansions are due to convergent evolution. However, relative to other fungi, including Metarhizium spp., many protein families are reduced in C. militaris, which suggests a more restricted ecology. Consistent with its long track record of safe usage as a medicine, the Cordyceps genome does not contain genes for known human mycotoxins. We establish that C. militaris is sexually heterothallic but, very unusually, fruiting can occur without an opposite mating-type partner. Transcriptional profiling indicates that fruiting involves induction of the Zn2Cys6-type transcription factors and MAPK pathway; unlike other fungi, however, the PKA pathway is not activated.

Conclusions

The data offer a better understanding of Cordyceps biology and will facilitate the exploitation of medicinal compounds produced by the fungus.