水稻NH4+转运蛋白基因OsAMT1.1~1.3，OsAMT3.1和OsAMT4.1表达部位及表达特性初析

以水稻为材料,对水稻NH4 离子转运蛋白基因OsAMT1.1、OsAMT1.2、OsAMT1.3、OsAMT3.1和OsAMT4.1的表达部位进行了初步的定性研究,并首次将荧光定量PCR技术应用于植物营养研究中,检测了水稻根中OsAMT1.1、OsAMT1.2、OsAMT1.3和OsAMT4.1在N饥饿48h以后,又转移到1mmol/LNH4 或1mmol/LNO3-中2h后的表达量变化。结果表明,在当时的实验条件下,OsAMT3.1主要在地上部表达,因此推测可能对于根系吸收NH4 没有多大作用;OsAMT1.1、OsAMT1.2、OsAMT1.3和OsAMT4.1在植株根部和地上部都有表达;经过48h的N饥饿处理以后,在检测的4个基因当中,根中表达量最高的是OsAMT1.1,显著高于OsAMT1.2、OsAMT1.3和OsAMT4.1,由此认为,对根中NH4 吸收的贡献也是OsAMT1.1最大;OsAMT1.2、OsAMT1.3和OsAMT4.1表达量在N饥饿48h以后,不论是NH4 或NO3-的加入都显著抑制这3个基因的表达。荧光定量PCR方法的应用可以精确检测到基因表达量的微小变化,尽管没有显著的变化,但从表达量上来讲,OsAMT1.1表达量在加N后有下降的迹象,而且OsAMT1.1、OsAMT1.2和OsAMT4.1受NH4 的抑制效果稍强于NO3-;而OsAMT1.3受NO3-的抑制作用稍强一点,这些都是半定量PCR和Northern杂交所检测不到的。

Expression Patterns of OsAMT (1.1-1.3), OsAMT3.1 and OsAMT4.1 in Rice(Oryza Sativa L.)

In order to investigate expression patterns of OsAMT in rice,a preliminary qualitative study was carried out on expressions of OsAMT1.1,OsAMT1.2,OsAMT1.3,OsAMT3.1,and OsAMT4.1 in rice shoot and root,and their respective expression levels except for OsAMT 3.1 in rice root in response to l mmol/L NH4 or 1mmol/L NO3-supply with the fluorescence RT-PCR technique for the first time. Results showed that expression of OsAMT3.1 was mainly confined to shoot,so it was presumed that OsAMT3.1 was insignificant to root NH4 uptake; expressions of OsAMT1.1,OsAMT1.2,OsAMT1.3 and OsAMT4.1 were found in both root and shoot; among the four genes detected,OsAMT1.1 was significantly higher than OsAMT1.2,OsAMT1.3 and OsAMT4.1 in expression level in all the three N treatments,so it was held that OsAMT1.1 contributed most to NH4 absorption in root; the expression level of OsAMT1.2,OsAMT1.3 and OsAMT4.1 were significantly suppressed after the application of NH4 or NO3-; slight variation of gene expression could be detected with the fluorescence RT-PCR technique; it was found that the expression of OsAMT1.1 decreased slightly after N application,and that the effect of NH4 on down regulation of OsAMT1.1,OsAMT1.2 and OsAMT4.1 was slightly stronger than that of NO3-and it was the other way around in the case of OsAMT1.3. These variations could not be detected with the semi-quantitative RT-PCR or blotting method.