不同氮素水平下大麦谷氨酰胺合成酶基因(HvGS1)表达及其与籽粒氮素积累的关系

Glutamine Synthase Gene(HvGS1)Expression and Its Relationship with Grain Nitrogen Accumulation under Different Nitrogen Levels in Barley

为探讨大麦(Hordeum vulgare L.)叶片谷氨酰胺合成酶(glutamine synthetase)基因(HvGS1)表达对氮素水平的响应及对籽粒氮素积累的影响,以蒙啤1号、蒙啤3号、甘啤4号和垦啤7号4个大麦品种为试验材料,设置0、90、180和270 kg·hm^(-2)4个施氮水平,分析灌浆期间不同供氮水平下大麦叶片HvGS1相对表达量的变化及其与籽粒氮积累的相关性。结果表明,随着施氮水平的增加,大麦叶片中HvGS1相对表达量上调;在灌浆期间,HvGS1相对表达量与供氮水平和籽粒氮含量均呈极显著正相关;随着灌浆进程推移,HvGS1相对表达量呈逐渐升高的趋势,直到花后28 d叶片开始衰老时仍维持较高的表达水平;成熟期籽粒氮含量与灌浆时期叶片HvGS1相对表达量呈极显著正相关。通径分析结果显示,对成熟期籽粒氮含量影响最大的是花后28 d HvGS1表达水平,其直接通径系数为0.4906。这说明施氮会促进HvGS1上调表达,进而增加籽粒氮素积累量。

In order to investigate the response of glutamine synthetase gene(HvGS1)expression in barley(Hordeum vulgare L.)under different nitrogen fertilizer levels and its effect on grain nitrogen accumulation,four barley varieties of Mengpi 1,Mengpi 3,Ganpi 4 and Kenpi 7 were used as test materials.Four pure nitrogen treatments of 0,90,180 and 270 kg·hm^(-2)were set up to analyze the changes of relative expression of HvGS1 in barley leaves and its correlation with grain nitrogen accumulation under different nitrogen supply levels during grain filling.The results showed that the relative expression of HvGS1 increased with the increase of nitrogen application level.During the filling period,the relative expression of HvGS1 was positively correlated with nitrogen supply and nitrogen content.With the process of filling,the relative expression of HvGS1 increased gradually until 28 days after anthesis,when the leaves began to senescence.There was a significant positive correlation between the nitrogen content at maturity stage and the relative expression of the HvGS1 in the leaves during grain filling.Path analysis results showed that HvGS1 expression level at 28 d after flowering was the most important factor affecting the grain nitrogen content at maturity,and the direct path coefficient was 0.4906.The expression of HvGS1 was significant positively related to the nitrogen supply level and nitrogen content,and was closely related to the grain nitrogen accumulation.