【摘要】 NAC家族是植物特有的一类转录因子,在植物的生长发育和逆境胁迫等方面具有重要的功能.研究发现,OsNAC2基因的过表达(ON11)和RNAi(RNAi31)转基因株系,早期主根的长度有显著变化的特征.与野生型日本晴水稻(WT)相比,ON11植株的主根变短,而RNAi31的主根变长.通过对早期OsNAC2pro∶∶GUS株系根尖染色结果表明OsNAC2在根尖具有时序性表达.不同激素诱导OsNAC2表达谱和OsNAC2pro∶∶GUS株系对激素响应结果显示OsNAC2受生长素显著性诱导.结合芯片数据和qRT-PCR分析,OsNAC2转基因株系中生长素合成代谢及信号通路相关基因表达量变化较为明显.同时,ON11根尖淀粉粒发育及其向重力性受到抑制.因此,推测OsNAC2可能通过抑制生长素的合成代谢及信号通路相关基因的表达,降低生长素含量,并参与生长素响应通路,最终影响水稻根的生长.更多还原

【Abstract】 The NAC family is one of the largest families of specific transcription factors in plant,which played a crucial role in plant development and environment stress.In this study,we found that constitutive overexpression of OsNAC2 in rice(ON11)reduced primary root length during early growth period,meanwhile RNAi transgenic line(RNAi31)has longer primary root length compared with WT.GUS staining showed that OsNAC2 temporal expressed in root tip.In addition,OsNAC2 was significantly induced by auxin after different hormone treatments.Furthermore,microarray analysis and qRT-PCR revealed that genes related to biosynthesis,metabolism and signaling pathway of auxin varied significantly among transgenic lines ON11,RNAi31 and WT.The starch grain development and gravitropism of root were also restrained in ON11.Taken together,OsNAC2 might regulate the expression of genes in auxin synthetic metabolism and signaling pathways,reduce the auxin concentration,involved in the auxin response pathways,and finally affect the rice root development.更多还原