Variation in defense enzymes in GT-2 and GAT-5 varieties of tomato during infection with bacterial wilt disease in Central Gujarat, India

Abstract

Bacterial wilt caused by Ralstonia solanacearum has been recognized as a serious threat to tomato plants which leads to significant loss in yield in the India and across the world. However, there is less information available about the interaction of R.solanacearum and Tomato bacterial wilt. The aim of the study was to show pathogenicity of bacterial wilt in two tomato varieties one, most susceptible (GT-2) and other tolerant (GAT-5) from Anand Central Gujarat. The enzymatic activity was examined for malondialdehyde (MDA) levels, phenylalanine ammonia lyase (PAL), peroxidase (POX), catalase (CAT), superoxide dismutase (SOD). The tolerant varieties had less disease symptom as compared to the susceptible variety. During bacterial wilt pathogenesis in tomato, causes oxidative burst due to encounter of ROS. Here we report, the total amount of phenol and MDA is significantly higher in the leaves of plants inoculated with R.solanacearum of both varieties over their non-inoculated control plants. The SOD, and PAL activity were lower in tolerant varieties and reduced considerably in susceptible varieties as compared to control plants, apart from PAL, which did not demonstrate a significant decline. When compared to non-inoculated plants, CAT enzyme activity were highest in both susceptible and tolerant varieties. The results demonstrate a rapid and rigorous production of reactive oxygen in plants against bacterial wilt and reveal that both varieties of tomato plants showed significant physiological changes during interaction with the R. Solanacearum.