外源氮素形态对苜蓿硝酸盐转运蛋白基因NRT1.3表达的影响

Effects of forms of inorganic nitrogen on the expression of nitrate transporter gene NRT1.3 in Medicago sativa L.

为探究添加不同形态氮素对紫花苜蓿幼根中硝酸盐转运蛋白基因NRT1.3表达的影响,试验设置4个处理,分别为对照（不加氮）、添加硝态氮、添加铵态氮和添加混合态氮,在紫花苜蓿分枝期测定了添加不同形态氮素后紫花苜蓿幼根中硝酸盐转运蛋白基因NRT1.3表达量的差异以及苜蓿生理指标、土壤氮含量对该基因表达的影响。结果表明：紫花苜蓿根中硝酸盐转运蛋白基因NRT1.3的表达量随着氮素的添加而显著增加（P〈0.05）,在添加混合态氮的处理中达到最高;土壤全氮、硝态氮和铵态氮浓度随氮素添加而显著升高（P〈0.05）,紫花苜蓿根中硝酸盐转运蛋白基因NRT1.3的表达量与土壤氮素浓度呈显著正相关关系（P〈0.05）。此外,试验结果也表明NRT1.3基因的表达与紫花苜蓿的株高、鲜重及叶绿素、硝酸盐含量也呈显著正相关关系（P〈0.05）。

In order to investigate the effects of forms of inorganic nitrogen on the relative expression in Alfalfa roots,we set up an experiment of 4 treatments include control（N-free）,nitrate N,ammonium N and mixed N of nitrate and ammonium. We measured the differences in expression of NRT1.3 on branching stage,and analyzed the effects of soil nitrogen concentration content and physical signs of alfalfa on the expression of NRT1.3. The results showed that the relative expression of NRT1.3 in alfalfa significantly increased with the N additions（P〈0.05）,and the highest at the treatment of add mixed N. Moreover,soil total N,nitrate N and ammonium N also significantly increased with N additions（P〈0.05）.Therefore,there were significantly positive correlations between the relative expression of NRT1.3 and soil N concentration（P〈0.05）. In addition,the relative expression of NRT1.3 also had a positive correlation with the physical characteristics of alfalfa,such as plant height,fresh weight,chlorophyll a＋b content,nitrate content,respectively（P〈0.05）.