| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2016477 | Plant Physiology and Biochemistry | 2011 | 7 Pages |
Striking increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) has been demonstrated to occur in plants in response to pathogen attack. The aim of this study was to investigate the biochemical aspects of ROS generation, antioxidative mechanism and cell wall reinforcement as responses of tomato cultivars Arka Meghali (AM; susceptible) and BT-10 (BT; resistant) against Ralstonia solanacearum (Ralsol). While the oxidative burst was characterized by a single phase ROS increase in AM, there was a clear bi-phasic ROS generation in BT. The first significant increase of H2O2 production was noticed at 12 h post-inoculation (hpi) followed by a sharp increase in H2O2 generation after 36 hpi. Lipid peroxidation was more in roots of AM than that of BT after pathogen inoculation. Superoxide dismutase and catalase activities were continuously at very high level in Ralsol-inoculated BT plants, whereas activities of the enzymes were observed to decrease at later stage in Ralsol-inoculated AM plants. Guaiacol peroxidase activity was high in Ralsol-inoculated roots of both cultivars, but BT recorded much higher activity than AM. Higher activity of ascorbate peroxidase in inoculated BT might be an indication of better scavenging activity of the enzyme. Total phenolic content and lignin deposition were significantly higher in Ralsol-inoculated BT compared to inoculated AM. Our results indicate that increased level of ROS production coupled with more efficient antioxidative system, lower rate of lipid peroxidation and high lignin deposition in cell wall may contribute to the resistance of tomato plants to Ralsol.
Research highlights► Biochemical aspect of oxidative burst was investigated in tomato against Ralstonia solanacearum. ► The oxidative burst was characterized by a single phase increase in Arka Meghali (AM; susceptible). ► There was a clear bi-phasic reactive oxygen species generation in BT-10 (BT; resistant). ► SOD, CAT and APX activities were continuously at very high level in Ralstonia-inoculated BT plants. ► Lignin deposition was significantly higher in Ralstonia-inoculated BT compared to inoculated AM.
