Biochemical mechanism of induced resistance to tomato bacterial wilt with the treatment of avirulent strains of Ralstonia solanacearum

Avirulent strains of Ralstonia solanacearum (ATm044 and ASp061) obtained by means of UVray mutation produced induced resistance to tomato bacterial wilt with the effect of 59.1% or 53.4%, which had no inhibiting effect on virulent strains, and could not become pathogeny of tomato. After the application of the strains, the activities of peroxidase(POD), phenylanine ammonia lyase(PAL) and polyphenoloxidase(PPO) in tomatos were increased significantly, and the contents of phenolic compounds and lignin in tomatos also markedly increased; the contents of pathogenesisrelated protein(PRP) were also increased. The results indicated that the mechanism of induced resistance to tomato bacterial wilt may be the changes in metabolism related to the resistance.