Analysis of defence enzymes induced by antagonistic bacterium Bacillus subtilis strain AR12 towards Ralstonia solanacearum in tomato

作者：Li Shi Mo; Hua Gou Gen; Liu Hong Xia^*; Guo Jian Hua

来源：Annals of Microbiology, 2008, 58(4): 573-578.

DOI：10.1007/bf03175560

• Bacillus subtilis
• Ralstonia solanacearum
• antioxidant enzyme
• detoxifying enzyme
• induced systemic resistance

Bacterial wilt, caused by Ralstonia solanacearum (Smith) Yabuuchi et al., is an economically important disease on tomato in many provinces of China. Antagonistic bacterium Bacillus subtilis strain AR12 was used to control bacteria wilt of tomato (Lycopersicon esculentum Miller) in the greenhouse. The biocontrol efficiency was as high as 90.18%. Superoxide anion and hydrogen peroxide generation rates and changes in phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) activities were studied in tomato plants. Antagonist AR12 advanced and increased significantly activities of PAL, PPO, POD, and SOD. As comparison, the activities of these four enzymes increased less and later in tomato only treated with R. solanacearum TM15 (control 2), and kept lowest level with few change in tomato with sterilised water (control 1). The maximum activities of these four enzymes in tomato treated with AR12 occurred in different stages: activity of PAL, PPO, POD, and SOD increased to the top level at 48, 48, 12 and 12 h, respectively, after pathogen inoculation and kept high level for some time. H(2)O(2) is associated with hypersensitive response (HR) during systemic acquired resistance. H(2)O(2) content increased significantly in tomato treated with AR12, but HR response was not seen. CAT and APX are the key H(2)O(2) detoxifying enzymes. Activities of APX in tomato treated with AR12 were increased significantly, while CAT was degraded until 80 h after pathogen inoculation. This work support the view that increased antioxidant enzyme activities could be involved, at least in part, in the beneficial effects of plant growth-promoting rhizobacteria strains on the performance of vegetable grown under the pathogen infection conditions.

• 出版日期2008
• 单位南京农业大学