Enhancement of NH_4^+ Uptake by NO_3^- in Relation to Expression of Nitrate-Induced Genes in Rice (Oryza sativa) Roots

This study aimed to survey the expression of genes involved in rice N uptake and aasimilatory network and to understand the potential molecular mechanisms responsible for the NO3^-enhanced NH4^＋ uptake. By using quantitative real-time polymerase chain reaction （PCR）, the genes related to N nutrition, including ammonium transporters （AMTs） and ammonium assimilatory enzymes （GS and GOGAT）, were transcriptionally analyzed in rice plants grown in the absence and presence of NO4^- in the NH4^＋-containing medium. The results showed that NH4^＋ uptake by rice was enhanced by the NO3^- supply to the medium. At the same time and in parallel, the amount of transcripts of seven genes （OsAMT1;1, OsAMT1;2, OsAMT4;1, OsGLNP, OsGLU1, OsGLT1, and OsGLTP） was increased in rice roots, but the expression of two genes （OsGLN1;1 and OsGLN1;P） was decreased and that of OsAMT1;3 remained without change. Up- or downregulation of these genes involved in NH4^＋ uptake and assimilation correlated with the increase in NH4^＋ uptake in the presence of NO3^- in rice roots.

这研究试图调查涉及米饭 N 举起和同化网络的基因的表示并且理解为 NO 负责的潜在的分子的机制 ? 3 提高的 NH+4 举起。由使用量的即时聚合酶链反应( PCR )，与 N 营养，包括的铵运输 ers ( AMT )和铵有关的基因同化的酶( GS 和 GOGAT )，在米饭植物分析的抄写联盟者在缺席和存在成长没有? 3 在包含的 NH+4 中等。结果证明由米饭的那 NH+4 举起被 NO 提高 ? 3 供应到媒介。同时并且在里面平行，七基因的抄本的数量( OsAMT1 ； 1 ， OsAMT1 ； 2 ， OsAMT4 ； 1 ， OsGLN2 ， OsGLN2 ， OsGLT1 ，和 OsGLT2 )在米饭根被增加，但是二基因的表示( OsGLN1 ； 1 并且 OsGLN1 ； 2 )被减少并且 OsAMTl 的；没有变化， 3 留下了。涉及 NH+4 举起和吸收的这些基因的起来规定或绒毛规定随 NH+4 举起的增加相关面对没有 ? 3 在米饭根。