Study On The Physiological Responses Of Silicon And Exogenous Nitric Oxide Application In Nostoc Flagelliforme Cell Under Drought Stress

Nostoc flagelliforme is a kind of terrestrial algae, widely distributed in arid andsemi-arid regions around the world, and has a strong ability of drought tolerance inpreventing land desertification.It can protect the ecological environment.In this study, Nostoc flagelliforme cell suspension were cultured under differentconcentrations of sodium silicate, exogenous nitric oxide and its interactions,physiological responses were studied by plant physiology and biochemistry method.The main results are presented as follows:1.With the increase of dry density, the Nostoc flagelliforme cell growth falledmore and more obvious, membrane permeability and malondialdehyde (MDA) contentshowed a trend of rising, SOD and POD enzyme showed a trend of falling after risingfirst, protein and trehalose and proline are gradually rising.2.Under low concentration of sodium silicate, Nostoc flagelliforme cell damageare reduced, and there are obvious dose effect,0.4mmol/L sodium silicate processioneffect is best. Under mild drought stress, Silicon can improve the Nostoc flagelliformeproline, soluble protein and trehalose content, significantly improve the protectiveenzymes SOD, POD activity, decrease the MDA content and cell membranepermeability, enhance the drought resistance of Nostoc flagelliforme.3.Under different concentrations of exogenous NO and drought stress, the Nostocflagelliforme cell damage reduction was deduced. The optimal concentration of SNPof50μmol/L. Exogenous NO increased growth trend under drought stress, themembrane permeability and MDA content decreased, increased enzyme system to acertain extent, for the influence of proline and soluble protein is not obvious.4.0.4mmol/L sodium silicate and50μmol/LSNP can accumulate osmotic regulation substances under stress. At the same time, the content of prolinesignificantly was increased. It effectively alleviate the drought stress to cell damage;significantly reduce the MDA content and membrane permeability, reduce themembrane lipid peroxidation, inhibit the cell electrolyte leakage, protect the structureof the cell membrane; At the same time further enhance the antioxidant activity of thecells. This shows that silicon and SNP could have a big potential for reduction ofoxidative damage to Nostoc flagelliforme under drought stress.