高温胁迫对高羊茅草坪草氮代谢的影响  

The Effect of High Temperature Stress on Nitrogen Metabolism of Tall Fescue Turfgrass

作　　者：宋子健[1] 李良霞[1] 李建龙[1] 张强[1] 

机构地区：[1]南京大学生命科学院,江苏南京210093

出　　处：《贵州农业科学》2007年第6期15-19,共5页Guizhou Agricultural Sciences

基　　金：江苏省农业三项工程项目"亚热型草坪草新品种和新技术的推广示范"[SX(2005)098]资助

摘　　要：通过盆栽试验,以两种耐热性不同的高羊茅(热耐受型美洲虎3号和热敏感型TF66)为材料,研究了高温逆境(35℃/30℃,昼/夜,20 d)对高羊茅叶片内总氮量、硝态氮含量和氨态氮含量以及参与氮同化和代谢过程的主要酶活性的影响。结果表明,高温胁迫下:(1)两种高羊茅叶片总氮量和硝态氮含量降低,氨态氮含量升高;(2)两高羊茅叶片内硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性均持续下降,谷氨酸合成酶(GOGAT)活性均先升后降;(3)高温胁迫20 d时美洲虎3号叶片内谷氨酸脱氢酶(GDH)活性较对照下降34.14%,而TF66叶片内GDH较对照上升了51.94%,表明TF66可能启动了通过谷氨酸脱氢酶同化铵的途径;(4)高温胁迫20 d时两高羊茅草种叶片内硝态氮含量、氨态氮含量、NR活性、GDH活性差异显著。综合结果可知,长时间的高温胁迫对两种高羊茅氮代谢的影响有所差异,这种差异可能是造成两种高羊茅耐热性不同的原因之一。Two tall fescue cultivars, Jaguar 3 （heat-tolerant） and TF 66 （heat-sensitive） were tested to investigate the effect of high temperature stress on its nitrogen metabolism under 35℃/30℃ （day/night） and 20 d. The results showed that under high temperature stress the total nitrogen content and nitrate content in the leaves of both tall fescue cultivars declined, ammonium content in the leaves of both tall fescue cultivars increased to varying degrees, the activity of nitrate reductase （NR） and NADH-dependent glutamate synthase （GS） decreased constantly, activity of glutamine synthetase （GOGAT） increased firstly and declined later in the leaves of both tall fescue cultivars. Under 20d of high temperature stress, the glutamate dehydrogenase（GDH） activity of Jaguar 3 decreased by 34.14 %, while that of TF 66 increased by 51.94 % compared with CK, which indicated that TF 66 might switch on the assimilation of ammonium way through glutamate dehydrogenase, and under 20 d of high temperature stress, there was significant difference in NR activity, GDH activity, nitrate content and ammonium content between two tested cultivars. In short, the long-term high temperature stress has the different effect on their nitrogen metabolism of two tested cultivars, which may be one of affecting the heat-tolerance reasons.

关 键 词：高温胁迫 高羊茅 氮代谢 氮含量 酶活性 

分 类 号：S688.4[农业科学—观赏园艺]