Abstract
Roots of higher plants seem to be advanced mechanisms to drought stress, since the root system is in direct contact for resistance to the soil. In this study, we analyzed drought-responsible proteins in the root tissues of wild watermelon (Citrullus lanatus sp. No101117-1) by the proteomic approach. Wild watermelon were exposed to the drought stress and the root soluble proteins were subjected to 2-D gel electrophoresis. The intensities of 35 spots were increased 1 day after the stress (Type I) and those of 42 spots were increased after 3 days (Type II). By LC-MS/MS analysis, cell division- and metabolism-related proteins were identified in Type I spots. On the other hand, various HSPs, antioxidative enzymes, and proteases were found in Type II spots. These results suggest that wild watermelon roots change the strategy in drought resistance from the induction of the adaptive to resistance mechanisms, during the progress of the stress.
