外源一氧化氮对镉胁迫下黑麦草生长和抗氧化酶活性的影响

利用一氧化氮(NO)供体硝普钠(sodium nitroprusside,SNP)0.1 mmol/L、Cd2 200 mg/L和SNP 0.1mmol/L Cd2 200 mg/L分别处理黑麦草幼苗.结果表明,与对照比较,SNP 0.1 mmol/L处理可增加黑麦草生物量、叶绿素含量、根系活力,降低丙二醛(malondialdehyde,MEA)含量、超氧阴离子(O2-·)产生速率和质膜透性,增强抗氧化酶活性;与对照比较,200 mg/L的Cd2 处理降低了黑麦草生物量、叶绿素含量、根系活力,使MDA含量和O2-·产生速率增加、质膜透性增大,抗氧化酶活性下降,植株体内积累Cd2 ;与Cd2 200 mg/L处理比较,SNP 0.1 mmol/L cd2 200 mg/L处理可提高黑麦草的生物量、叶绿素含量、根系活力,降低MDA含量和O2-·产生速率、质膜透性,而抗氧化酶活性增强,植株体内Cd2 积累量也明显下降.因此,外源NO对Cd胁迫下黑麦草生长有一定的缓解作用,可以增强黑麦草对Cd毒害的抗性.

Effect of exogenous nitric oxide on the growth and antioxidant enzyme activities of Lolium perenne under Cd stress

Lolium perenne seedlings were treated with SNP(a NO donor) 0.1 mmol/L,Cd2 200 mg/L and SNP 0.1 mmol/L Cd2 200 mg/L.Compared with the CK,SNP at 0.1 mmol/L increased biomass amount,chlorophyll content and root activity,but decreased MDA content,generation rate and membrane permeability,while enhanced the antioxidant enzymes activities of L.perenne seedlings.However,200 mg/L Cd2 decreased biomass amount,chlorophyll content and root activity,but increased MDA content,generation rate,membrane permeability,and accumulated Cd2 .The antioxidant enzymes activities decreased.Compared with Cd2 200 mg/L treatment,SNP 0.1 mmol/L promoted biomass amount,chlorophyll content and root vigor,but decreased MDA content,generation rate,membrane permeability and Cd2 content of L.perenne seedlings,while increased the antioxidant enzyme activities of the seedlings increased under Cd2 200 mg/L stress.The results indicated that exogenous nitric oxide(NO) had a mitigating effect on the growth of seedlings under Cd2 200 mg/L stress,and enhanced the resistance of them to Cd toxicity.