水稻响应镉胁迫转录因子（OsNAC300）功能研究
毕业论文关键词: OsNAC300；过表达；镉胁迫
Research on Function of Cadmium Stress Responsive Transcription Factor OsNAC300 in Rice
Abstract: The purpose of this study was to investigate whether OsNAC300 is involved in the response of rice to cadmium (Cadmium, Cd) stress. 20 days-old Rice seedlings were treated with solutions containing 0, 0.5, 5 and 50 μM cadmium for 3 days, and the growth index and cadmium content were determined. The rice seedlings which overexpressing OsNAC300 showed higher growth rate and larger biomass compared with wild type, but there was no significant difference in cadmium tolerance ability and cadmium content. In addition, using OsNAC300p:GUS transgenic rice as material, we treated rice seedlings for 24 hours using +Cd and -Cd conditions, and carried out GUS staining and microscopy observation. The results of GUS staining showed that cadmium stress significantly induced the expression of OsNAC300 in roots. In conclusion, we found that: OsNAC300 may only respond to cadmium stress at the transcriptional level, but does not affect the uptake and tolerance of rice to cadmium; we suggest OsNAC300 may be involved in the regulation of the growth process of rice seedlings.
Key words: OsNAC300；Overexpression；Cadmium stress
目 录
摘要1
关键词1
Abstract1
Key words1
引言1
1 材料与方法3
1.1 研究材料 3
1.2 研究材料培养 3
1.3 试剂3
1.4 分析检测3
1.4.1 OsNAC300过表达材料镉胁迫下生长指标的测定3
1.4.2 消煮4
1.4.3 原子吸收分光光度法测定材料中镉的含量4
1.4.4 GUS染色法观察OsNAC300表达分布4
1.4.5 数据处理5
2 结果与分析5
2.1 OsNAC300的过表达转基因水稻对镉胁迫的耐受性表型分析5
2.1.1 OsNAC300的过表达转基因水稻在镉胁迫下生长指标分析5
2.1.2 OsNAC300的过表达转基因水稻在镉胁迫下镉积累量分析6
2.2 OsNAC300在镉胁迫下表达情况分析7
3 小结 8
4 讨论8
致谢9
参考文献9
水稻响应镉胁迫转录因子（OsNAC300）功能研究
转录因子(transcription factor, TFs)是一类能与基因启动子区域内顺式作用元件特异性结合，从而调节目的基因以特定的强度在特定的时间与空间表达的蛋白质分子，因此也称为反式作用因子。NAC转录因子是一类于植物中存在的转录因子，其命名源于牵牛花NAM、拟南芥ATAF1/2和CUC2基因的首字母。在过去的十几年中，NAC家族的成员在不同植物中被陆续报导，例如水稻[1]、小麦[2]、拟南芥[3]等。作为一个重要的基因家族，NAC转录因子家族参与了植物生长发育过程中的很多生理进程，也在植物受到生物胁迫[4]和非生物胁迫[5][6]的过程中起到调节作用。
NAC转录因子具有一个保守的N端NAC区(NAC 结构域)和一个多样的C端转录调节(TR)区[4]。Ernst等(2004)通过对拟南芥ANAC019、水稻NAC1和一年生禾草SiNAC
转录因子的NAC 结构域进行分析，发现NAC 结构域具有一个N-端α螺旋和一个反向平行的β折叠[7]。NAC 结构域具有结合DNA的能力。转录调节区(TRRs)一般位于C末端，可以起到激活或抑制转录的作用[3]。TRR由低复杂度的序列组成，因此TRRs表现出高度内在无序化(ID)，从而保证C末端的灵活性，使NAC转录因子能够结合不同的互作蛋白[8]。
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