Abstract：
CrgA has been shown to be a negative regulator of carotenogenesis in some filamentous fungi, while light irradiation is an inducible environmental factor for carotenoid biosynthesis. To clarify the relationship between CrgA and light-inducible carotenogenesis in Blakeslea trispora, the cis-acting elements of the btcrgA promoter region were investigated, followed by the analyses of correlation between the expression of btcrgA and carotenoid structural genes under different irradiation conditions. A variety of cis-acting elements associated with light response was observed in the promoter region of btcrgA, and transcription of btcrgA and carotenoid structural genes under different irradiation conditions was induced by white light with a clear correlation. Then, RNA interference and overexpression of btcrgA were performed to investigate their effects on carotenogenesis at different levels under irradiation and darkness. The analyses of transcription and enzyme activities of carotenoid structural gene, and accumulation of carotenoids among btcrgA-interfered, btcrgA-overexpressed, and wild-type strains under irradiation and darkness indicate that btcrgA negatively regulates the synthesis of carotenoid in darkness, while promotes the carotenogenesis under irradiation regardless of reduced or overexpression of btcrgA .
摘要：
在一些丝状真菌中，CrgA已被证明是类胡萝卜素发生的负调节剂，而光照是类胡萝卜素生物合成的可诱导环境因素。为了阐明三孢囊的CrgA与光诱导的类胡萝卜素发生之间的关系，研究了btcrgA启动子区的顺式作用元件，然后分析了不同辐照条件下btcrgA表达与类胡萝卜素结构基因的相关性。在btcrgA的启动子区域观察到与光响应相关的多种顺式作用元件,白光诱导btcrgA和类胡萝卜素结构基因在不同照射条件下的转录具有明显的相关性。然后进行RNA干扰和btcrgA的过表达，以研究它们在辐射和黑暗下对不同水平的类胡萝卜素生成的影响。类胡萝卜素结构基因的转录和酶活性分析,和btcrgA干扰的类胡萝卜素的积累，btcrgA过表达和野生型菌株在辐射和黑暗下表明btcrgA在黑暗中负调节类胡萝卜素的合成，同时促进照射下的胡萝卜素生成，而不管btcrgA的减少或过度表达。
