College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China.
Hubei International Scientific and Technological Cooperation Base of Traditionally Fermented Foods, Wuhan, China.
J Appl Microbiol. 2022 Aug;133(2):591-606. doi: 10.1111/jam.15586. Epub 2022 Apr 30.
Monascus spp. are valuable industrial fungi for producing beneficial compounds. Because sporulation is often coupled with the production of secondary metabolites, the current study was performed to investigate how Mrada3 regulated asexual and sexual development and the production of edible pigments and mycotoxin.
The functional characteristics of Mrada3 were identified by gene deletion and overexpression in Monascus ruber M7 (the wild-type, WT). The results revealed that the ΔMrada3 strain aborted sexual development, but it produced many more conidia than WT. RNA-seq data showed that the deletion of Mrada3 altered the expression levels of partial genes involved in sexual and asexual development. In addition, the deletion of Mrada3 also resulted in slower growth, lower pigment production and increased citrinin yield during the late period. For the Mrada3-overexpressed strain, the number of ascospores and pigment content were significantly higher than those of WT, but citrinin was slightly lower than that of WT.
The Mrada3 gene plays a vital role in the sporulation development and secondary metabolism of Monascus species.
Mrada3 is first identified as an essential regulator for sexual development in Monascus species, enriching the regulatory knowledge of sexual development in filamentous fungi.
红曲霉是一种具有重要工业价值的真菌，可用于生产有益化合物。由于孢子形成通常与次生代谢产物的产生相关联，因此本研究旨在探讨 Mrada3 如何调节无性和有性发育以及食用色素和真菌毒素的产生。
通过在红曲霉 M7（野生型，WT）中进行基因缺失和过表达，鉴定了 Mrada3 的功能特征。结果表明，ΔMrada3 菌株中止了有性发育，但产生了比 WT 更多的分生孢子。RNA-seq 数据显示，Mrada3 的缺失改变了部分参与无性和有性发育的基因的表达水平。此外，Mrada3 的缺失还导致在后期生长速度变慢、色素产量降低和桔霉素产量增加。对于 Mrada3 过表达菌株，子囊孢子的数量和色素含量明显高于 WT，但桔霉素略低于 WT。
Mrada3 基因在红曲霉属的孢子形成发育和次生代谢中起重要作用。
Mrada3 首次被鉴定为红曲霉属中性发育的必需调节剂，丰富了丝状真菌性发育的调控知识。
