AEM Accepts, published online ahead of print on 23 October 2009

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Jin, K. Articles by Pei, Y. PubMed PubMed Citation Articles by Jin, K. Articles by Pei, Y. Agricola Articles by Jin, K. Articles by Pei, Y.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol. doi:10.1128/AEM.00882-09
Copyright (c) 2009, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

A carboxylate transporter gene BbJEN1 from the entomopathogenic fungus Beauveria bassiana is involved in the conidiation and virulence

Kai Jin, Yongjun Zhang, Weiguo Fang, Zhibing Luo, Yonghong Zhou, and Yan Pei^*

Key Laboratory of Biotechnology and Crop Quality Improvement of Ministry of Agriculture of China, Biotechnology Research Center, Southwest University, Chongqing, 400716, P. R. China; Genetic Engineering Research Center, Institute of Bioengineering, Chongqing University, Chongqing, 400030, P. R. China

^* To whom correspondence should be addressed. Email: peiyan3{at}swu.edu.cn.

Beauveria bassiana is an important entomopathogenic fungus widely used as a biological agent to control insect pests. A gene (BbJEN1) homologous to JEN1 encoding a carboxylate transporter in Saccharomyces cerevisiae was identified from a B. bassiana T-DNA insertional mutant. The disruption of the gene decreased the amount of carboxylate contents in hyphae, while increased the conidial yield. Whereas, overexpression of this transporter resulted in a significant increase of carboxylates, and decreased the conidial yield. BbJEN1 was strongly induced by insect cuticles and highly expressed in the hyphae penetrating insect cuticles not in hyphal bodies, suggesting that this gene is involved in the early stage of pathogenesis of B. bassiana. Bioassay result indicated that the disruption of BbJEN1 significantly reduced the virulence of B. bassiana to aphids. Compared to the wild type, BbJEN1 alkalinized the insect cuticle to a lesser extent. The alkalinization of the cuticle is a physiological signal triggering the production of pathogenicity. Therefore, we identified a new factor influencing virulence, which is responsible for the alkalinization of the insect cuticle and the initiation of fungal pathogenesis in insects.