Carboxylate transporter gene JEN1 from the entomopathogenic fungus Beauveria bassiana is involved in conidiation and virulence.
Beauveria bassiana is an important entomopathogenic fungus widely used as a biological agent to control insect pests. A gene (B. bassiana JEN1 [BbJEN1]) homologous to JEN1 encoding a carboxylate transporter in Saccharomyces cerevisiae was identified in a B. bassiana transfer DNA (T-DNA) insertional mutant. Disruption of the gene decreased the carboxylate contents in hyphae, while increasing the conidial yield. However, overexpression of this transporter resulted in significant increases in 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. The bioassay results indicated that disruption of BbJEN1 significantly reduced the virulence of B. bassiana to aphids. Compared to the wild type, DeltaBbJEN1 alkalinized the insect cuticle to a reduced 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.
Jin
Kai
K
Key Laboratory of Biotechnology and Crop Quality Improvement of the Ministry of Agriculture of China, Biotechnology Research Center, Southwest University, Chongqing 400716, People's Republic of China.
Zhang
Yongjun
Y
Fang
Weiguo
W
Luo
Zhibing
Z
Zhou
Yonghong
Y
Pei
Yan
Y
D000818:Animals; D001042:Aphids / Q000382:microbiology; D052982:Beauveria / Q000235:genetics* / Q000254:growth & development*; D002264:Carboxylic Acids / Q000378:metabolism*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D023061:Gene Order; D005800:Genes, Fungal; D025301:Hyphae / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D027501:Monocarboxylic Acid Transporters / Q000235:genetics; D016254:Mutagenesis, Insertional; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D017385:Sequence Homology; D013172:Spores, Fungal / Q000254:growth & development*; D016019:Survival Analysis; D027981:Symporters / Q000235:genetics; D014774:Virulence
D002264:Carboxylic Acids; C118697:JEN1 protein, S cerevisiae; D026901:Membrane Transport Proteins; D027501:Monocarboxylic Acid Transporters; D029701:Saccharomyces cerevisiae Proteins; D027981:Symporters