EFFECT OF GLYCINE BETAINE ON BRASSICA JUNCEA GROWN UNDER HEAT AND SALT STRESS IN A HYDROPONIC SYSTEM

Abstract

Indian mustard is mostly targeted for commercial cultivation as an early-sown or late-sown crop with the expectation of higher seed yield and oil content. Indian mustard is grown under different agro-ecological situations, so exposed to abiotic stress like heat and salinity. The accumulation of osmolytes like glycine betaine (GB) in cell is known to protect organisms against abiotic stresses via osmoregulation or osmoprotection. Hydroponics systems provides an excellent tool for stress related studies. In the present study, the growth of Indian mustard was compared in a hydroponic system, soil system and cocopeat system. The effect of aeration in a hydroponic system was also assessed. It was found that the plants grew equally well in soil and hydroponic system but aeration drastically increased the growth rate in the initial days. The plants grown in hydroponic system were induced heat stress by growing them in a plant growth chamber at 45°C and salt stress was induced by adding 2% NaCl in the nutrient solution. Glycine betaine was extracted from Bacillus subtilis grown under salt stress. This extract was added in the nutrient solutions to alleviate the effect of stress in the plants. The control plants kept under stress conditions showed a decrease in the growth rate which was alleviated in the test plants subjected to stress and grown with glycine betaine extract. More effect was seen in the plants subjected to salt stress.