不同氮源对高温胁迫下高羊茅抗氧化酶活性的影响

Effects of Different Nitrogen Forms on Antioxidative Enzyme Activity in Leaves of Festuca arundinacea under Heat Stress

通过盆栽实验,研究了不同氮源(NO3--N、NH4+-N、NH4NO3-N)处理对凌志高羊茅品种(Festuca arundineceaschrebcv.Barlexas)在高温[38℃/30℃(昼/夜)]胁迫下保护酶活性和膜脂过氧化的影响。结果表明,各指标在不同氮源处理间存在较大差异,具体表现在高温胁迫下:(1)NH4+-N和NO3--N处理株叶片MDA含量均持续增加,在相同胁迫程度下,NO3--N处理株的增幅小于NH4+-N处理株;NH4NO3-N处理株的叶片MDA含量先降后升,但变化幅度较小且保持在较低水平;(2)NH4+-N、NO3--N和NH4NO3-N处理株的叶片SOD、POD、APX活性均先升后降,CAT活性均不同程度的持续下降;(3)在相同胁迫水平下,NH4NO3-N处理株的叶片SOD、POD、CAT、APX活性均最高,NO3--N处理株其次,NH4+-N处理株最低。在本试验条件下,NH4NO3-N处理的高羊茅受氧化胁迫程度最小,耐热性最好。

The plot experiment was conducted to investigate effects of different nitrogen forms （NO3^--N, NH4^＋-N, NH4NO3-N） on antioxidative enzyme activity and MDA in leaves of Festuca arundinacea under high temperature（38℃/30℃, day/ night）. The results indicated that （1） the MDA content in leaves treated by NO3^--N and NH4^＋-N increased constantly and the increase range treated by NO3^--N was lower than that treated by NH4^＋-N under same heat stress, the MDA content in leaves treated by NH4NO3-N declined slightly first and increased later but the change range was little. （2）the SOD , POD and APX activity in leaves treated by NO3^--N,NH4^＋-N and NH4NO3-N all raised first and declined later, but the CAT activity declined constantly to varying degrees. （3）the SOD, POD, CAT and APX activity in leaves of plants treated by NH4NO3-N was the highest in three nitrogen forms under the same heat stress, which indicated that Festuca arundinacea treated with NH4NO3-N was of the better anti-oxidation ability and heat tolerance.