Expression Analysis of Droughtinduced Genes in Wild Tomato Line (Solanum habrochaites)

Many plant genes are regulated in response to abiotic stresses such as drought, high salinity, heat and cold, and their gene products function in stress response and tolerance. The whole process of plant adaptation to these environmental stresses is controlled by orchestration of complex molecular networks. In the present study, eight genes showing significant difference of expression on exposure to artificial drought stress in tomato, were selected from the previously performed microarray experiment. Expression analysis of the genes was done semi-quantitatively as well as quantitatively under artificially imposed drought stress and the results were almost similar to those of microarray experiment. Tissue-specific analysis of the genes, performed on tolerant line, revealed fairly a similar pattern of expression in ischolar_main, stem and leaf with notable differences in flower, which experienced the least influence of drought. The results confirmed that SIPRP16, SICYP51-17, SIMCPI19 and SIGDSL20 were downregulated in both the lines with stronger downregulation in sensitive line. SIWRKY4 was downregulated in both the lines with more folds of downregulation in tolerant line. SIEFH12 and SISNF4-15 were upregulated in tolerant line. SlUSPA9 was upregulated in both the lines with relatively more folds of upregulation in sensitive line.