Yun Choong-Soo, Motoyama Takayuki, Osada Hiroyuki
Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science , 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
ACS Chem Biol. 2017 Sep 15;12(9):2270-2274. doi: 10.1021/acschembio.7b00353. Epub 2017 Aug 24.
Tenuazonic acid (TeA) is a mycotoxin produced by the rice blast fungus Pyricularia oryzae and some plant pathogenic fungi. We previously demonstrated that TeA is biosynthesized in P. oryzae by TeA synthetase 1 (TAS1) and that its production is induced by osmo-sensory MAPK-encoding gene (OSM1) deletion or the addition of 1% DMSO to cultures; however, the regulatory mechanisms of TeA production were unknown. Here, we identify a Zn(II)-Cys-type transcription factor in the upstream region of TAS1, which is encoded by TAS2 and regulates TeA production. We also find PoLAE1, which is a homologue of LaeA, a regulator of fungal secondary metabolism. Analysis of PoLAE1 deletion and overexpression strains indicate that PoLAE1 drives TeA production. We also demonstrate that two TeA-inducing signals, 1% DMSO addition and OSM1 deletion, were transmitted through PoLAE1. Our results indicate that TeA production is regulated by two specific regulators, TAS2 and PoLAE1, in P. oryzae.
细交链孢菌酮酸（TeA）是由稻瘟病菌稻梨孢菌和一些植物病原真菌产生的一种霉菌毒素。我们之前证明，TeA在稻梨孢菌中由细交链孢菌酮酸合成酶1（TAS1）生物合成，其产生可由编码渗透感应丝裂原活化蛋白激酶的基因（OSM1）缺失或向培养物中添加1%二甲基亚砜诱导；然而，TeA产生的调控机制尚不清楚。在此，我们在TAS1的上游区域鉴定出一种锌（II）-半胱氨酸型转录因子，其由TAS2编码并调控TeA的产生。我们还发现了PoLAE1，它是真菌次级代谢调节因子LaeA的同源物。对PoLAE1缺失和过表达菌株的分析表明，PoLAE1促进TeA的产生。我们还证明，两种诱导TeA产生的信号，即添加1%二甲基亚砜和缺失OSM1，是通过PoLAE1传递的。我们的结果表明，在稻梨孢菌中，TeA的产生受两种特定调节因子TAS2和PoLAE1的调控。
