Osmotic Stress Induced The Accumulation Of Plant Cells, The Mechanism Of The Aba

Water stress induce the high and quick accumulation of plant hormone abscisic aicd(ABA),which reduce the stomatal conductance of leaves, decrease the loss of water, and improve plant tolerance to water stress. In order to elucidate the mechanism how plant to perceive the water stress, suspension cultured system of tobacco cell was established in the experiment and the mechanism how tobacco cells perceive the mannitol tress was studied. The results show that suspension cultured tobacco cells can tolerate the mannitol stress. Osmotic stress of 0.4mol-L-1 mannitol does not change the cycle of cell growth, bout inhibit the cell growth. The level of osmotic stress induced-ABA accumulation is relative to the content of stress. The critical concentration of mannitol stress is 0.8-0.9mol-L-1. The maximal level of ABA accumulation is attached after 5 hours' treat with 0.9mol -L-1 mannitol solution. Cell wall plays important roles in tobacco cells perception to osmotic stress. Stress induced-ABA accumulation of tobacco protoplasts is obviously lower than it of tobacco cells. Integrin-like protein may involve in osmotic stress induced-ABA accumulation. Pretreat of 0. 15mmol-L-1 RGD(Arg-Gly-Asp) reduces the interaction between cell wall and plasma membrane and inhibits the stress induced-ABA accumulation by 50 percent. Light, as the unnecessary factor for tobacco cell suspension culture, have some effects on the stress induced-ABA accumulation. Under dark condition, stress induced-ABA accumulation decreases by 50 percent.Beside, Effect of -carotene inducer ((2-diethylamino)-ethyl-4-methylbenzyl -ether) on the endogenous ABA levels and drought tolerance of maize was studied. The experimental results showed that 0.1%(w/w) inducer can lightly inhibit the ABA biosynthesis of maize under normal conditions, while it can improve the ABA levels obviously and the drought tolerance of maize under water stress.