Zhao Dongying, Li Hui, Cui Yanru, Tang Shengyue, Wang Chengqiang, Du Binghai, Ding Yanqin
College of Life Sciences and Shandong Engineering Research Center of Plant-Microbia Restoration for Saline-alkali Land and Shandong Key Laboratory of Agricultural Microbiology and National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Shandong Agricultural University, Tai'an, China.
Front Microbiol. 2022 Nov 22;13:1039806. doi: 10.3389/fmicb.2022.1039806. eCollection 2022.
The multiple-sugar metabolism regulator (MsmR), a transcription factor belonging to the AraC/XylS family, participates in polysaccharide metabolism and virulence. However, the transcriptional regulatory mechanisms of MsmR1 in remain unclear. In this study, knocking out was found to reduce polymyxin synthesis by the SC2-M1 strain. Chromatin immunoprecipitation assay with sequencing (ChIP-seq) revealed that most enriched pathway was that of carbohydrate metabolism. Additionally, electromobility shift assays (EMSA) confirmed the direct interaction between MsmR1 and the promoter regions of , , , , , , , and . MsmR1 stimulates polymyxin biosynthesis by directly binding to the promoter regions of and , while also directly regulating and influencing the citrate cycle (TCA cycle). In addition, MsmR1 directly activates and was beneficial for spore and biofilm formation. These results indicated that MsmR1 could regulate carbohydrate and amino acid metabolism, and indirectly affect biological processes such as polymyxin synthesis, biofilm formation, and motility. Moreover, MsmR1 could be autoregulated. Hence, this study expand the current knowledge of MsmR1 and will be beneficial for the application of SC2 in the biological control against the certain pathogens in pepper.
多糖代谢调节因子（MsmR）是一种属于AraC/XylS家族的转录因子，参与多糖代谢和毒力。然而，MsmR1在……中的转录调控机制仍不清楚。在本研究中，发现敲除……会降低SC2-M1菌株的多粘菌素合成。染色质免疫沉淀测序分析（ChIP-seq）表明，最富集的途径是碳水化合物代谢途径。此外，电泳迁移率变动分析（EMSA）证实了MsmR1与……、……、……、……、……、……、……和……的启动子区域之间存在直接相互作用。MsmR1通过直接结合……和……的启动子区域来刺激多粘菌素生物合成，同时还直接调节……并影响柠檬酸循环（TCA循环）。此外，MsmR1直接激活……并有利于孢子和生物膜形成。这些结果表明，MsmR1可以调节碳水化合物和氨基酸代谢，并间接影响多粘菌素合成、生物膜形成和运动性等生物学过程。此外，MsmR1可以自我调节。因此，本研究扩展了当前对MsmR1的认识，并将有利于SC2在辣椒中对某些病原体进行生物防治的应用。
