不同铵硝比例对水稻铵吸收代谢基因表达的影响

以水稻南光为材料,研究了不同铵硝摩尔比例处理时,水稻NH4^＋吸收代谢基因的表达情况.档结果表明：（1）应用荧光定量PCR方法,可以精确检测水稻氮素吸收代谢基因在不同铵硝处理间的表达量变化;（2）从各基因的表达量上来看,吸收基因中以OsAMT1.1表达量最高,编码GS的基因中以OsGln1.1表达量最高,编码GOGAT的基因中,OsGlu表达量最高;（3）总体来说,不同铵硝处理对NH4^＋吸收代谢基因的表达有显著影响,吸收基因对不同铵硝比例的反应要比代谢基因更敏感;（4）氮吸收基因中OsAMT4.1显著受到NO3的抑制,NH4^＋的诱导.而OsAMT1.1,OsAMT1.2,OsAMT1.3和OsNRT2在铵硝摩尔比例由100：0变为50：50过程中,受到NO3^-的显著抑制,在铵硝摩尔比例由50：50变为0：100过程中OsAMT1.2和OsAMT1.3受到NO3^-的显著诱导,OsAMT1.1和OsNRT2变化不显著;（5）编码GS的基因OsGln1.1表达受NO3诱导,受NH4^＋抑制.OsGln2在铵硝摩尔比例由100：0变为50：50过程中,受到NO3^-增加的诱导,同时,OsGln1.2受到NO3增加的显著抑制作用,铵硝达到50：50以后,NO3^-比例的增加对OsGln1.2和OsGln2的表达没有显著影响;（6）编码GOGAT的基因OsGlt1和OsGlu在不同铵硝摩尔比例中的变化趋势一致：铵硝比例由100：0变为50：50过程中没有显著变化,铵硝比例50：50基础上表达量受到NO3^-比例增加的显著抑制,而OsGlt2的表达受NO3^-的显著抑制,NH;的显著诱导.

INFLUENCE OF AMMONIUM/NITRATE RATIO IN TREATMENT ON EXPRESSION OF NITROGEN ABSORBING AND METABOLIZING GENES OF RICE

In order to clarify nitrogen uptake and metabolism of rice roots on a molecular basis, studies by means of quantitative real-time PCR were carried out on expression of nitrogen absorbing and metabolizing genes in relation to different ammonium/nitrate ratio in treatment.The results show that (1) in terms of expression level, OsAMT1.1 among N absorbing genes, OsGln1.1 among GS genes and OsGlu among GOGAT genes was the highest; (2) Significant up-regulation by ammonium and down-regulation by nitrate were found in the expression of OsAMT4 1, in any treatment whereas significant nitrate-depressed expression for OsAMT1.1, OsAMT1.2, OsAMT1.3 and OsNRT2 was observed when the ratio of ammonium to nitrate varied from 100:0 to 50: 50, and significant nitrate-induced expression for OsAMT1.2 and OsAMT1.3 when the ratio of ammonium to nitrate varied from 50:50 to 0:100; (3) Among the genes coded as GS, OsGln1.1 were significantly up-regulated by nitrate and down-regulated by ammonium, significant nitrate-induced expression for OsGln2 and nitrate-depressed expression for OsGln1.2 when the ration of ammonium to nitrate varied from 100:0 to 50:50; (4) Among the genes coded as GOGAT, OsGlt1 and OsGlu showed no significant variation in the process of the ratio of ammonium to nitrate varying from 100:0 to 50:50, but were significantly down-regulated with the ratio of ammonium to nitrate further varying from 50:50 to 0:100; significant up-regulation by ammonium and down-regulation by nitrate were found in the expression of OsGlt2; (5) In general, the regulation of expression of these genes by ammonium and nitrate depends on the ratio of ammonium to nitrate in the primary solution where the rice grew.