目录
摘要II
关键词II
AbstractIII
引言
引言1
1材料与方法5
1.1植物材料 5
1．2 GhNCED3s基因序列的获取与生物信息学分析 5
1．3 GhNCED3s表达分析 5
1．4 ABA含量测定 5
1．5 棉花耐盐性鉴定 5
1．6 SNP单倍型分析 5
1．7 统计学分析6
2 结果与分析 6
2．1 陆地棉TM1基因组GhNCED3基因序列的鉴定6
2．2 GhNCED3的组织表达分析 6
2．3 不同棉花材料GhNCED3的表达、ABA含量与耐盐性鉴定 9
2．4 GhNCED3a基因编码区在海陆棉种中SNP位点的鉴定 10
2．5 SNP引物的开发11
3 讨论 13
致谢14
参考文献14
ABA合成关键基因NCED3在棉花中的单倍型分析
摘 要
脱落酸（ABA）是一种重要的植物激素，可以调节植物生长发育，帮助植物抵抗多种逆境胁迫。9顺式环氧类胡萝卜素双加氧酶(NCED)是植物体内ABA合成的关键限速酶，其中NCED3基因是植物逆境胁迫下ABA生物合成的关键基因。本试验对陆地棉TM1基因组GhNCED3基因序列进行了鉴定，共发现6个GhNCED3s基因，分别将其命名为GhNCED3aAt, GhNCED3aDt, GhNCED3bAt, GhNCED3bDt,GhNCED3cAt, GhNCED3cDt, 其中同一基因对应的A亚组与D亚组之间序列同源性较高，可以合并为3对基因。以TM1两叶一心期的根和叶为材料对GhNCED3基因进行就了组织表达分析发现GhNCED3a表达量最高；并设计A和D亚组特异引物进行基因定量表达分析，发现来源于A亚组的GhNCED3aAt基因在棉花根和叶组织中表达量较高，D亚组来源的基因表达量较低；同时对不同棉花材料GhNCED3的表达、ABA含量与耐盐性进行了比较鉴定，发现三者之间相关性较好（R2=0.6316）；对G *51今日免费论文网|www.jxszl.com +Q: ^351916072^ 
hNCED3a基因编码区序列在已测序公布的棉花材料中比对发现，存在两种单倍型变异(C/T,T/A)，该研究为后续的NCED基因在棉花中的进化和功能研究奠定了基础。
HAPLOTYPE ANALYSIS OF THE KEY GENE NCED3 OF ABA SYNTHESIS IN COTTON
ABSTRACT
Abscisic acid (ABA) is an important plant hormone, which can regulate the growth and development of plants and help plants to resist a variety of stress. 9ciscyclocarotenoid dioxygenase (NCED) is the key rate limiting enzyme of ABA synthesis in plants, and the NCED3 gene is the key gene of ABA biosynthesis in plants under stress. In this experiment, the GhNCED3gene sequence of TM1 genome of upland cotton was identified. Six GhNCED3s genes were found, which were named GhNCED3aAt, GhNCED3aDt, GhNCED3bAt, GhNCED3bDt, GhNCED3cAt and GhNCED3cDt respectively. Among them, the sequence homology between subgroup A and subgroup D of the same gene was high, and they could be combined into three pairs of genes. The expression of GhNCED3a gene was the highest in the roots and leaves of TM1 two leaves at one stage. The quantitative expression of GhNCED3a gene was analyzed with specific primers of A and D subgroups. It was found that the expression of GhNCED3a at gene from A subgenome was higher in the roots and leaves of cotton, but lower in D subgroups. Meanwhile, the expression of GhNCED3a gene from different cotton materials was analyzed. The results showed that there were two haplotypes in the coding region of GhNCED3a gene, which laid a foundation for the further research of NCED gene in cotton.
KEY WORDS：GhNCED3; RTqPCR; salt tolerance identification; haplotype analysis
引言：棉花是重要的经济作物，油料作物，也是天然纤维的主要来源[1]。棉花种植面积十分广阔，全球超过三分之一的国家将其作为纤维的最重要来源进行种植[23]。经过人类不断地驯化和选育，现在种植面积最多的是四倍体的海岛棉和陆地棉。在我国，这两种棉花主要集中在新疆西北地区种植，西北地区干旱缺水。干旱胁迫对棉花种植和收获有极为深刻的影响，有研究表明干旱胁迫对棉花生长发育所产生的危害大于其他非生物逆境胁迫带来的危害总和[4]，由此可见研究棉花抗旱是十分有意义且非常重要的。而早在上世纪中后期科学家们就在棉花中发现了一种可以帮助植物抵抗干旱胁迫的植物激素脱落酸（ABA），而随着研究的深入科学家们发现了脱落酸还具有促进种子休眠、抑制种子萌发，调节气孔开放，抑制生长加速衰老等生理功能，在植物抗寒、抗盐、抗虫等方面也有功效。

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