Manipulating tomato plant electric signaling system by microwave radiation to enhance crop productivity and nutritional value

The present study was undertaken to explore the stimulatory effect of microwave radiation on growth and development of Lycopersicon esculentum Mill. (tomato) plant. These signal stimuli propagate and encode information which alters and manipulate the plant signaling system. Two varieties of tomato seeds i.e. NS-585 and NS-2535 were exposed to microwave radiation at 9.3 GHz for 0-8 h where 0 h seeds were treated as control. Exposure to microwave radiation showed enhanced germination rate and speed germination index and increment in the β-1,3-glucanase activity which clearly suggested the stimulation of the germination rate and seedling vigour of the tomato seedlings. Microwave radiation showed increment in the bioactive compounds like polyphenol and flavonoid, chlorophyll, carotenoid and protein content of the tomato plant exposed for 4-5 h; further increase in the microwave dose reduced the growth and other biochemical content in the tomato plant. Growth related modification in tomato seedlings were characterized using FT-IR spectroscopy which clearly confirmed the increase in pectin, lignin, protein, carbohydrate and lipid content in the microwave irradiated tomato seedlings. It is suggested that controlled and defined microwave radiation may help in enhancing crop productivity.