Study On Antioxidant System Of Alnus Formosana Under Salt Stress And Regulation Of Exogenous Nitric Oxide

This paper regarded annual Alnus formosana as the research subject,and no salt(0mol/LNaCl), low-salt (0.1mol/LNaCl), moderate-salt (0.2mol/LNaCl), high-salt(0.3mol/LNaCl) with different concentration of exogenous nitric oxide (sodiumnitroprusside,SNP:0.05mmol/L,0.1mmol/L,0.2mmol/L and sodium nitrite,NaNO₂:0.1mmol/L,0.5mmol/L,1.0mmol/L)treatment was carried out. Study on the influence of antioxidant systemand soils' nutrient elements of alnus formosana under salt stress with exogenous nitric oxidetreatment and evaluated it's function and degree. To explorate the physiological and biochemicalchange characteristics under salt stress and regulatory mechanism of exogenous nitric oxide. Atthe same time it can be indicated to provide theory guide for introducing Alnus formosana inhigh-salt conditions in the coastal areas.The results of the studies are listed as follows:1.The death of alnus formosana increases gradually and the survival rate gradually declinedwith the increasing of exposure time and concentration of salt stress.e.g. The survival rate ofalnus formosana dropped to20%,40%,60%from100%under high-salt stress (0.3mol/LNaCl)with0.05mmol/LSNP,0.1mmol/LNaNO₂treatment after20days.The results indicated that wouldaggravate the pernicious effects of salt with salt stress concentration is increased,and it alsoshowed that the exogenous nitric oxide had some alleviate effects for the survival of alnusformosana under salt stress.2.The exogenous nitric oxide had a bigger different influence on soil C,N,P,K of alnusformosana under salt stress. With the increasing of concentration fo salt stress,the soil C contenthad increased15.71%,5.72%,23.09%,12.47%respectively,P(treatment by NaNO₂)increased20.83%,3.57%respectively as compared with blank control under regulated by low-concentrationof SNP and NaNO₂.Likewise,the soil N content increased16.84%,17.46%,17.37%,13.20%respectively,P(treatment by SNP) increased29.17%,63.16%,0.83%,3.57%respectively. TheNP and NaNO₂had no regulation effects for K.It was obvious that salt stress could cause someinhibition of nutrient elements of soil,and the exogenous nitric oxide could markedly amelioratedit.3.All antioxidation indexes of alnus formosana,except for O₂^.-,shows an earlier raised andlater decreased state only under salt stress.Compared with treatment CK,the SPC,CAT,SOD, POD,MDA,SPAD,N,P content decreased25.81%,25.30%,4.78%,16.79%,36.35%,3.25%,33.49%,17.20%respectively,C,K increased5.26%,45.59%respectively aftertreatmented20days.The O₂^.-content had increased apparently under all different concentration ofsalt stress,and increased36.80%than CK.The results shows that the alnus formosana had somesalt tolerancy in early salt stress,but it would be poisoned with the increasing of exposure time andconcentration of salt stress.The increased content of O₂^.-indicated that active oxygen incrcasedhad aggravated the inhibition of cell,protein,nucleotide of alnus formosana udner salt stress.4.The exogenous nitric oxide SNP and NaNO₂had significantly alleviating effect for allphysiological Indexes of alnus formosana under salt stress.The nitric oxide could markedlyincrease antioxidant Enzyme activity of CAT,SOD,POD and the content of SPC,MDA,C,N,P,K,it also had an inhibition effect on increased content of O₂^.-and could decrease the cellmembrane disease by active oxygen.But the response was different of all physiological Indexes ofalnus formosana, the concentration of NO donor and NaCl stress was positively correlated withthe physiological Indexes of SOD,POD,MDA,SPAD(treatment by NaNO₂),C,N,P,andnegative correlation with the physiological Indexes of SPC,CAT,SPAD(treatment by SNP),O₂^.-,K.There was a bigger difference of regulation effects between SNP and NaNO₂,and itsoptimum concentration of regulation effects was varied by the concentration of salt stress.