Reactive Oxygen Metabolism and Response to Meloidogyne incognita Infection in Tomato ‘Ls-89’ and ‘Banzhen 2’ Rootstock Seedlings

Abstract:

In order to understand the relation between reactive oxygen (ROS) metabolism of tomato (Lycopersicon esculentum) rootstock seedlings and their resistance to Meloidogyne incognita, a high sensitive rootstock ‘Ls-89’ and a high resistant rootstock ‘Banzhen 2’ were planted in pots and inoculated with M. incognita, the effect of M. incognita infection on ROS metabolism and related enzyme activities in tomato rootstock seedlings was studied. The results showed that ROS level and related enzyme activities in roots and leaves had no significant difference between two varieties uninfected by M. incognita. After inoculated by M. incognita, both O₂·^- generation rate and H₂O₂ content in roots and leaves of two varieties increased, and those in ‘Banzhen 2’ were significantly higher than those in ‘Ls-89’, while MDA content in ‘Ls-89’ was significantly higher than that in ‘Banzhen 2’. At the early stage of infection, SOD activity decreased in roots and leaves of both varieties, and the decline in ‘Banzhen 2’ was bigger than that in ‘Ls-89’. The POD and CAT activities changed hardly at early stage of infection, and then significantly enhanced in middle and late infection stage. Therefore, the resistant rootstock seedlings had strong lipid antioxidant ability and high ROS level, and SOD activity in tomato rootstock seedlings was sensitive to the infection of M. incognita.