3种苔藓植物对模拟大气氮沉降的生理响应OACSTPCD

Bryophyte is an important component of the surface ecosystem.The physiological response of bryophyte(Syntrichia caninervis,Bryum argenteum and Plagiomnium acutum)to nitrogen deposition could provide insights into how to use bryophyte scientifically and rationally to indicate the atmospheric nitrogen deposition.Three bryophytes in the northwest of China were selected as materials,and four different nitrogen treatment concentrations(0(N0),2(N2),4(N4),6(N6)g·m-2)were set up,the physiological responses of three bryophytes to the above nitrogen concentration gradients were indicated by measuring the contents of chlorophyll,osmotic regulators and antioxidant enzyme activities.The results showed that:(1)P.acutum of chlorophyll a and chlorophyll b was promoted by 4 nitrogen treatments,especially by N4 treatment.However,N2 had significant inhibitory effects on chlorophyll a and chlorophyll b of B.argenteum and S.caninervis.(2)Proline(Pro),soluble sugar(SS)and soluble protein(SP)were produced in bryophytes to regulate cell osmotic balance.The contents of Pro,SS and SP in B.argenteum and P.acutum all increased under different nitrogen concentrations,but the contents of Pro,SS and SP in mosses decreased under low nitrogen treatment,indicating S.caninervis were more sensitive to N.(3)under the given nitrogen addition treatment,the antioxidant enzyme activities of three bryophytes were promoted by low concentration of nitrogen,but inhibited by high concentration of nitrogen.(4)SOD and CAT played major role in the regulation of the antioxidant system in S.caninervis,B.argenteum and P.acutum,respectively.In conclusion,S.caninervis was the most sensitive to nitrogen increase of the three bryophytes,followed by P.acutum.And B.argenteum,suggesting that S.caninervis could be used as an indicator plant for atmospheric nitrogen deposition.