Mutualistic Co-evolution of Type III Effector Genes in Sinorhizobium fredii and Bradyrhizobium japonicum

• DOI: 10.1371/journal.ppat.1003204
• Publication Date: 2013-03-01T13:34:41Z
• Authors: Jeffrey A. Kimbrel; William J. Thomas; Yuan Jiang; Allison L. Creason; Caitlin A. Thireault; Joel L. Sachs; Jeff H. Chang
• Keywords: Bradyrhizobium; Bradyrhizobium japonicum; Sinorhizobium

Two diametric paradigms have been proposed to model the molecular co-evolution of microbial mutualists and their eukaryotic hosts. In one, mutualist host exhibit an antagonistic arms race each partner evolves rapidly maximize own fitness from interaction at potential expense other. opposing model, conflicts between are largely resolved is characterized by evolutionary stasis. We tested these frameworks in two lineages mutualistic rhizobia, Sinorhizobium fredii Bradyrhizobium japonicum. To examine genes demonstrably important for host-interactions we coupled mining genome sequences a comprehensive functional screen type III effector genes, which necessary many Gram-negative pathogens infect demonstrate that rhizobial surprisingly high degree conservation content sequence contrast those well plant pathogenic species. This gene particularly striking context relatively genome-wide diversity rhizobia. The evolution effectors inconsistent with paradigm. Instead, our results reveal loci static suggest rhizobia plants resolved.