玉米雄穗响应干旱胁迫的主要代谢途径解析及耐旱SNAC基因筛选鉴别

发布时间：2018-03-25 17:24

本文选题：玉米　切入点：干旱　出处：《新疆农业大学》2015年博士论文

【摘要】：干旱是限制我国玉米生产的主要环境因子之一。掌握玉米响应干旱胁迫的主要代谢途径并发掘有价值的耐旱基因,对玉米耐旱育种具有重要的指导意义。本研究以10份我国生产上常用的骨干玉米自交系为材料,设干旱胁迫处理和正常灌溉处理,使用控制浇水法在雄穗小花分化发育时期进行干旱胁迫,对雄穗样品进行转录组测序。通过分析干旱胁迫处理下差异表达基因,研究雄穗发育过程中响应干旱胁迫的主要代谢途径,进而发掘和鉴选出转录因子NAC家族中的响应干旱胁迫的SNAC基因。主要研究结果如下：1.利用转录组测序技术对10份自交系干旱胁迫处理与正常灌溉处理发育雄穗进行RNA测序。结果显示每份样品平均获得4,692万个完整的测序片段,有3,410万个测序片段可以与玉米参考基因序列进行唯一性匹配。20份玉米样品平均检测到2.90万个表达基因,其中平均每份自交系有1,902个是雄穗在干旱胁迫处理下差异表达基因(P"f0.001,错误率"f0.001,差异表达倍数在2倍以上)。2.干旱胁迫下差异表达基因的GO功能分类结果显示共有286个显著富集的功能分类标签(P0.05),其中参与细胞组分的功能分类标签有129个,参与生物过程的功能分类标签有101个,参与分子功能的功能分类标签有56个。本研究中通过GO分类在分子功能层次注释了3,121个雄穗中响应干旱的差异表达基因。3.通过分析雄穗响应干旱胁迫的差异表达基因在KEGG数据库中富集的代谢途径,结果显示雄穗在转录水平上主要通过转录调节、能量代谢、碳水化合物代谢、脂类代谢、次级代谢物合成和萜类与聚酮类化合物代谢等途径来响应干旱胁迫。其中,转录调节中RNA转录和EmRNA监控途径显著富集；能量代谢中光合作用、光合作用-触角蛋白和氮代谢途径显著富集；碳水化合物代谢中戊糖磷酸化和半乳糖代谢途径显著富集；萜类和聚酮类化合物代谢中类胡萝卜素合成、柠檬烯与蒎烯分解和双萜类合成代谢途径显著富集；其它次级代谢产物合成代谢中黄酮类合成和花青素合成代谢等途径显著富集；脂类代谢的基因主要在脂肪酸伸长显著富集并调控蜡质合成过程(P0.05)。4.在干旱胁迫下,玉米雄穗在转录水平主要通过外显子连接复合体基因调控RNPS1和SRm160对干旱胁迫进行响应。在碳水化合物代谢中响应干旱胁迫的主要基因是转化酶基因和6-磷酸果糖激酶基因,包括mn1、ivr2、GRMZM2G095725、 GRMZM2G017991、GRMZM2G398807;在脂类代谢中响应干旱胁迫的主要基因是3-酮脂酰辅酶A合成酶和脂肪酰基辅酶A还原酶基因,包括GRMZM2G409312、 GRMZM2G062718和msh1。5.通过筛选耐旱自交系铁7922雄穗响应干旱胁迫转录组数据库,发现干旱胁迫下ZmNAC010312(P=2.99×10-28)、ZmNAC030295(P=1.61×10-21)、ZmNAC080308(P=1.11×10-10)在干旱胁迫下显著上调。进一步通过与模式植物已知功能的NAC基因的序列结构进行比对,发现三个NAC家族成员与水稻中已知具有抗旱或抗脱水功能基因具有相同的motif结构,预测上述三个基因为响应干旱胁迫的耐旱候选SNAC基因。
[Abstract]:Drought is one of the major environmental factors limiting maize production in China. To master the main metabolic response of Maize to drought stress and drought tolerance genes to explore the way of value, has an important guiding significance for drought tolerance in maize breeding. In this study, 10 of China's corn production backbone of commonly used inbred lines as materials, design and processing of drought stress the normal irrigation treatment, control of water use in tassel floret differentiation period of drought stress, transcriptome sequencing of tassel samples. Through the analysis of gene expression difference under drought stress treatment, the main metabolic pathways in response to drought stress on tassel development process, and then explore and discriminating SNAC transcription factor NAC gene in response to drought in the family of stress. The main results are as follows: 1. using transcriptome sequencing of 10 inbred lines under drought stress and normal irrigation development in tassel For RNA sequencing. The results showed that each sample averaged 46 million 920 thousand complete sequencing of the fragments, 34 million 100 thousand fragments can only match the average detection to 29 thousand.20 samples of maize and maize gene expression reference gene sequence, of which the average of each inbred line 1902 is the tassel gene expression under drought stress (difference P "f0.001, f0.001, error rate expression ratio of more than 2 times) GO functional classification of gene expression under drought stress difference.2. the result showed that there were 286 significantly enriched functional classification label (P0.05), which involved in the function of classification and labelling of cell components are 129, functional classification labels involved in biological process 101, functional classification labels involved in molecular function 56. In this study, through the GO classification at the molecular level annotation function gene expression.3. response to drought and the difference of the 3121 tassels Analysis of tassel difference in response to drought stress the expression of metabolic pathway genes in the KEGG database showed that enrichment of the tassel at the transcriptional level mainly through transcriptional regulation, energy metabolism, carbohydrate metabolism, lipid metabolism, and the way of polyketide compounds metabolism and biosynthesis of secondary metabolites and terpenoids in response to drought stress. Among them, transcription the regulation of RNA transcription and EmRNA control approach is significantly enriched in energy metabolism; photosynthesis, photosynthesis and nitrogen metabolism of antenna protein significantly enriched; pentose phosphorylation and galactose metabolic pathways of carbohydrate metabolism were significantly enriched in class; terpenoids and polyketide metabolism of carotenoids synthesis, limonene and pinene decomposition and diterpene the synthesis pathway is significantly enriched; synthesis and metabolism of other secondary metabolites of flavonoids synthesis and anthocyanin synthesis metabolism significantly enriched Lipid metabolism; gene in fatty acid elongation significantly enriched and regulation of wax synthesis process (P0.05).4. under drought stress, maize tassel at the transcriptional level by exon junction complex gene regulation of RNPS1 and SRm160 in response to drought stress. In carbohydrate metabolism in response to drought stress is the main gene invertase gene 6- and phosphofructokinase gene, including Mn1, ivr2, GRMZM2G095725, GRMZM2G017991, GRMZM2G398807 in lipid metabolism; drought stress response gene mainly is 3- keto acyl coenzyme A synthetase and fatty acyl coenzyme A reductase gene, including GRMZM2G409312, GRMZM2G062718 and msh1.5. through the screening of drought tolerant inbred line 7922 iron tassel in response to drought stress transcriptome database, found under drought stress ZmNAC010312 (P=2.99 * 10-28), ZmNAC030295 (P=1.61 * 10-21), ZmNAC080308 (P=1.11 * 10-10) in drought Under the stress increased significantly. Further through the sequence structure of NAC gene with known function in the model plant for comparison, found three known NAC family members in rice with resistance to dehydration or drought resistant functional genes having the same motif structure, the prediction of these three genes in response to drought tolerant candidate SNAC gene under drought stress.

【学位授予单位】：新疆农业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：S513;S423

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