低氮胁迫下大麦谷氨酰胺酶基因的表达分析

EXPRESSION ANALYSIS OF GLUTAMINE SYNTHETASE GENE IN BARLEY UNDER LOW-NITROGEN STRESS

谷氨酰胺酶是氮代谢中的关键酶,在氨同化和谷氨酰胺生物合成中起着重要的作用。为研究谷氨酰胺酶基因在大麦耐低氮中的作用机理,本研究利用荧光定量PCR技术检测了大麦中这两类谷氨酰胺酶基因(GS1和GS2)在低氮胁迫下的表达情况,并分析了谷氨酰胺酶基因在耐低氮大麦基因型BI-04和低氮敏感大麦基因型BI-45间的表达差异。结果表明,GS1基因在BI-04中表现为上调表达,而在BI-45中表现为下调表达,但随着时间的延长其表达量恢复并超过对照;而GS2基因在两种大麦基因型中的表达差不多,都表现为下调表达。另外,本文也观察到大麦谷氨酰胺酶基因的表达在黑暗条件下受到抑制,因此推测其也受到光照条件的影响。

Glutamine synthetase（GS） is a key enzyme in nitrogen metabolism,it plays important roles in ammonia assimilation and glutamine biosynthesis.To reveal the mechanisms of glutamine synthetase genes on low-nitrogen tolerance in barley,the expression patterns of GS1 and GS2 genes in leaves under low-nitrogen stress were analyzed by real time RT-PCR in this study,and the different expression between the low-nitrogen tolerance genotype BI-04 and the sensitive type BI-45 were observed.The results showed that the expression level of GS1 was up-regulated rapidly after low-nitrogen treating 1h in genotype BI-04,while it was down-regulated in genotype of BI-45,but the expression resumed after treating 24h.The expression patterns of GS2 in the two genotypes were all down-regulated.In addition,both of these two types of GS genes were restrained obviously in the dark condition,so we inferred that these genes were infected by lights.