Molecular mechanisms of differences in pathogenicity between Ralstonia solanacearum strain RsTP2 and RsTY2

The molecular mechanisms between different Ralstonia solanacearum strains with varied pathogenicity were studied to help the control of tobacco bacterial wilt disease in the future. Two strains RsTP2 and RsTY2 were isolated from diseased tobacco plants in Guangchang county and Nanfeng county of Fuzhou, Jiangxi Province. Egl gene sequencing results revealed that both strains were sequevar 13 belonged to Asian phylotype I. The infestation test results indicated that RsTP2 strain was more aggressive to Yunyan87 tobacco plants, in contrast to less pathogenicity of RsTY2 strain. Draft genome maps of RsTP2 and RsTY2 were obtained by high-throughput sequencing technique. Genes sequences showed 52 proteins of RsTY2 and 44 protein of RsTP2 were different in the alignment with similarity between 50% and 99.88%. Most of the differential proteins were hemagglutinin, followed by hemolysin secretion activating protein and phage holin family protein. Gene sequence differences of these three types of proteins were suspected to be critical for different pathogenicity between strain RsTP2 and RsTY2.