Genes Expression Change in Barrel Medic in Response to Ralestonia solanacearum

Legumes are important crop plants as human and animal feeds. They are able to establishnitrogen-fixing symbiosis with soil rhizobia and also to form symbiotic root mycorrhizae. Thesoilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt and attacks more than 200 plant species, including some legumes. This pathogen blocks the plant vessels and also can digest the plant key enzymes via secretion system type III resulting in plant death. In this study, the resistant and susceptible Medicago truncatula were used as model plants to investigate the gene expression changes against R. solanacearum. The proteomics and transcriptomics studies showed that the expression of two groups of genes increases in both resistant and susceptible plants against R. solanacearum. The first group, including the product of resistance genes such as PI, PR and peroxidase proteins interacts with pathogen directly. The second group is genes that play as transcription factors, signal transduction or chaperon like proteins such as HSP90 and peptidyl-prolyl cis-trans isomerase (PPI). The transcriptomics studies showed that the induction of gene expression in the resistant plants were stable but transient in the susceptible plants. One day after bacterial inoculation, the genes expression were induced in both resistant and susceptible plants but reduced in susceptible plants in day three post inoculation.