小麦转录因子基因TaNAC8B的表达分析与抗逆功能研究

发布时间：2018-03-25 15:26

本文选题：小麦　切入点：NAC　出处：《华中科技大学》2016年硕士论文

【摘要】：干旱、高盐以及极端温度等不利因素严重影响植物的正常生长发育,使农作物的产量下降、品质降低。植物在长期的进化过程中,形成了一系列调控机制以适应或抵御不利环境的影响,转录因子调控基因表达就是其中之一。转录因子可以通过与相应的顺式作用元件结合,调控相关基因的时空表达,响应不同逆境胁迫。近年来植物特有且为最大的转录因子家族之一的NAC(NAM,ATAF与CUC)在抗逆功能方面的研究报道越来越多,但大部分研究工作都集中在模式植物拟南芥和水稻上,而关于小麦NAC转录因子的功能研究还鲜有报道。本研究在实验室前期工作基础上,分析了小麦NAC转录因子家族成员Ta NAC8B基因的表达模式和转录激活活性;通过根癌农杆菌介导的遗传转化法获得了Ta NAC8B过表达的转基因烟草株系,并研究了其抗逆功能。主要研究成果如下:(1)通过模拟不同逆境胁迫,用实时荧光定量PCR方法检测了Ta NAC8B基因的表达变化,发现PEG6000处理可显著上调Ta NAC8B的表达,而Na Cl、ABA和低温等胁迫处理下Ta NAC8B表达量没有显著变化。(2)构建p GBKT7-Ta NAC8B真核表达载体,通过酵母自激活实验,发现Ta NAC8B具有转录激活活性,且转录激活活性区域位于Ta NAC8B C-端。(3)利用根癌农杆菌介导的遗传转化技术,成功将Ta NAC8B转入烟草并获得阳性植株。通过对T1代种子的模拟逆境胁迫处理下的根长实验,发现Ta NAC8B过表达植株表现出较强的抗逆性。进一步通过对幼苗的干旱胁迫处理,观察表型以及测定相关生理指标,发现Ta NAC8B过表达植株表现出较强的抗旱性能,这与Ta NAC8B基因表达模式分析和根长实验结果一致。综上所述,Ta NAC8B转录因子可以响应干旱逆境胁迫处理,过表达Ta NAC8B植株表现出较强的干旱胁迫耐受性,这为进一步研究Ta NAC8B的基因功能奠定了基础。
[Abstract]:Drought, high salt, extreme temperature and other adverse factors seriously affect the normal growth and development of plants, resulting in lower crop yields and lower quality. Plants have evolved over a long period of time. A series of regulatory mechanisms have been formed to adapt to or resist adverse environmental effects, and transcription factor regulation gene expression is one of them. Transcription factors can regulate the expression of related genes in time and space by combining with the corresponding cis-acting elements. In recent years, there are more and more studies on stress resistance of NACU NAMMAF and CUC, one of the largest transcription factor families, but most of the research work is focused on Arabidopsis thaliana and rice. However, there are few reports on the function of wheat NAC transcription factors. Based on the previous work in laboratory, the expression pattern and transcriptional activation activity of Ta NAC8B gene, a member of wheat NAC transcription factor family, were analyzed. Transgenic tobacco lines with Ta NAC8B overexpression were obtained by Agrobacterium tumefaciens mediated genetic transformation, and their stress resistance was studied. The expression of Ta NAC8B gene was detected by real-time fluorescence quantitative PCR. It was found that PEG6000 treatment could significantly upregulate the expression of Ta NAC8B, while the expression of Ta NAC8B did not change significantly under NaCl NAC8B and low temperature stress.) the eukaryotic expression vector of p GBKT7-Ta NAC8B was constructed. Through yeast self-activation experiment, we found that Ta NAC8B has transcriptional activation activity, and the transcriptional activation region is located at the C- terminal of Ta NAC8B, using Agrobacterium tumefaciens mediated genetic transformation. Ta NAC8B was successfully transferred into tobacco and positive plants were obtained. Through the experiment of root length of T1 generation seeds under simulated stress stress, it was found that Ta NAC8B overexpression plants showed strong resistance to stress. The phenotypic and physiological indexes were observed, and it was found that the plants with Ta NAC8B overexpression showed strong drought resistance. These results are consistent with the analysis of Ta NAC8B gene expression pattern and the results of root length experiment. In conclusion, Ta NAC8B transcription factors can respond to drought stress stress, and over-expressed Ta NAC8B plants exhibit strong tolerance to drought stress. This lays a foundation for further studying the gene function of Ta NAC8B.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：Q943.2;S512.1

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