水稻响应镉胁迫相关转座子鉴定
毕业论文关键词：转座子；水稻转录组；镉胁迫
Identification of Rice Transposable Elements in Response to Cadmium Stress
Abstract：Transposable elements (TEs or transposons) are important components in plant genomes, affecting the size of the genome, composition, stability, gene expression and regulation and many other aspects. With the development of next-generation sequencing technology and bioinformatics technology, TEs are identified on a large scale and people's understanding of transposon is more and more in-depth. Although the origin and presence of transposons have been controversial and even known as selfish DNA, there is growing evidence that transposons can create new genes and regulate gene expression, especially in Epigenetic regulation and so on. In this study, bioinformatics methods were used to study the effect of transposon on the genome under environmental stress. The study was conducted by comparing the differences in gene expression in rice transcripts under cadmium stress and no stress, identifying transposons in rice that responded to them, and genes that may be regulated by these transposons. The method is novel and has a clear idea that the transposon and functional genes related to cadmium stress in rice can be detected on large scale at the transcriptome level, which has the potential to do the biological function research.
Key words: Transposable Elements (TEs or transposons)；Rice Transcriptome；Cadmium Stress
目 录
摘要1
关键词1
Abstract1
Key words1
引言1
1材料与方法6
1.1 实验材料 6
1.2 水稻培养 6
1.3 处理6
1.4 RNA-seq6
1.5 测序结果数据处理 6
1.5.1 构建差异表达数据库6
1.5.2 分析差异表达的转座子6
2 结果与分析7
2.1 水稻表型7
2.2 RNA-seq数据分析7
2.2.1转座子的差异表达相关分析7
2.2.2差异表达转座子的染色体定位与亚类分析8
2.2.3附近差异表达基因相关分析10
3 讨论10
致谢12
参考文献12
水稻响应镉胁迫相关转座子鉴定
引言
水稻(Oryza sativa )因其相对小的基因组、高密度的遗传和物理图谱、相对容易的遗传转化和与其它禾谷类具有共线性关系等特点，已成为单子叶植物的模式植物之一[1]。此外，水稻是最重要粮食作物之一,也是世界1/2以上人口的主食,与其相关的遗传学和分子生物学研究一直倍受研究者的重视。而产量是水稻研究中极为重要的一个方面，研究非生物胁迫对水稻产量产生的影响将有利于作物改良。
重金属胁迫是重要的一类非生物胁迫，其中镉是一种对植物生长发育有毒害作用的重金属元素，土壤中的镉易经植物的根吸收运送到地上部分。作物中镉元素含量过量会影响作物产量，尤是可食用部分镉富集时更会危害人类健康。研究表明，水稻可以通过多种途径响应镉胁迫，对镉的毒害有一定的抵御能力。镉在根系被吸收，然后通过木质部运送至地上部，最后可以分布到稻谷中。在Cd2+的吸收转运过程中，生物体有一定的防御措施，首先，耐镉品种根部的细胞壁可以吸附大部分Cd2+，这是水稻在短时间和低浓度镉胁迫下的重要防护方式[2]；第二，多种转运蛋白通过将Cd2+排出胞外或运送至液泡来达到解毒、隔离的效果[3]，胞质中的非蛋白羟基类分子有一定解毒效果，如谷胱甘肽(GSH)能在谷胱甘肽Ｓ转移酶(GST)的催化下螯合Cd2+，使其失活[4]；最后，当镉胁迫造成细胞伤害时，胞内的抗氧化系统和热激蛋白等会被激活，通过清除活性氧[5]、降解或修复受损蛋白[6]等方式来降低镉毒害。