Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing, China.
State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultura Sciences, Beijing, China.
Elife. 2023 Apr 25;12:e84743. doi: 10.7554/eLife.84743.
Division of labor, where subpopulations perform complementary tasks simultaneously within an assembly, characterizes major evolutionary transitions of cooperation in certain cases. Currently, the mechanism and significance of mediating the interaction between different cell types during the division of labor, remain largely unknown. Here, we investigated the molecular mechanism and ecological function of a policing system for optimizing the division of labor in SQR9. During biofilm formation, cells differentiated into the extracellular matrix (ECM)-producers and cheater-like nonproducers. ECM-producers were also active in the biosynthesis of genomic island-governed toxic bacillunoic acids (BAs) and self-resistance; while the nonproducers were sensitive to this antibiotic and could be partially eliminated. Spo0A was identified to be the co-regulator for triggering both ECM production and BAs synthesis/immunity. Besides its well-known regulation of ECM secretion, Spo0A activates acetyl-CoA carboxylase to produce malonyl-CoA, which is essential for BAs biosynthesis, thereby stimulating BAs production and self-immunity. Finally, the policing system not only excluded ECM-nonproducing cheater-like individuals but also improved the production of other public goods such as protease and siderophore, consequently, enhancing the population stability and ecological fitness under stress conditions and in the rhizosphere. This study provides insights into our understanding of the maintenance and evolution of microbial cooperation.
分工，即亚群在一个集合中同时执行互补任务，在某些情况下是合作的主要进化转变的特征。目前，在分工过程中调解不同细胞类型之间相互作用的机制和意义在很大程度上仍然未知。在这里，我们研究了优化 SQR9 分工的警察系统的分子机制和生态功能。在生物膜形成过程中，细胞分化为细胞外基质（ECM）生产者和类似骗子的非生产者。ECM 生产者也积极参与基因组岛控制的毒性杆菌酸（BAs）和自我抗性的生物合成；而非生产者对这种抗生素敏感，可以部分消除。Spo0A 被确定为触发 ECM 产生和 BAs 合成/免疫的共同调节剂。除了其众所周知的 ECM 分泌调节作用外，Spo0A 还激活乙酰辅酶 A 羧化酶产生丙二酰辅酶 A，这是 BAs 生物合成所必需的，从而刺激 BAs 的产生和自我免疫。最后，该警察系统不仅排除了不产生 ECM 的骗子样个体，而且还提高了其他公共物品（如蛋白酶和铁载体）的产生，从而增强了在胁迫条件下和根际中的种群稳定性和生态适应性。这项研究为我们理解微生物合作的维持和进化提供了新的认识。
