Abstract
Biotic stress on Lycopersicon esculentum laden by the various biotrophic and necrotrophic fungal pathogens forms the most devastating diseases of tomato plants in India. In this study, the expression of defense-related genes was carefully evaluated in silicon (Si) treated and Alternaria solani inoculated plants by using reverse transcription polymerase chain reaction (RT-PCR) and real time quantitative polymerase chain reaction (qRTPCR). We also determined the effect of Si on disease prevention and free radical scavenging potential. Based on the outcomes, it was found that Si has a tremendous impact on expression of ACCO, TSRF1, POD and CHI II in Si + A. solani inoculated plants than control and plants that were only inoculated with A. solani. However, ACCO gene showed less expression in Si treated condition than other genes. Furthermore, prior addition of Si diminishes the levels of ROS and increases the scavenging activity of free radical as DPPH, Hydroxyl, Superoxide anion and hydrogen peroxide in Lycopersicon esculentum. Altogether, In response to A. solani, Si not only increases the transcription levels of defence signature genes, but also the transcription levels of other genes and also free radical scavenging potential in tomato plants was enhanced.