本文關鍵詞：稀有變異揭示TCP基因調控黃瓜卷須發(fā)育　出處：《中國農業(yè)科學院》2016年博士論文　論文類型：學位論文

  更多相關文章： 稀有變異 TCP轉錄因子 黃瓜卷須 同源器官

【摘要】：卷須是葫蘆科瓜類作物株型研究最重要的方面之一,也是研究植物向觸性運動的重要的植物模式器官。黃瓜的基因組、轉錄組和變異組的測序工作的完成,為系統(tǒng)研究黃瓜提供了大數據平臺支持。本課題搜集了世界各地3342份黃瓜種質資源,發(fā)現唯一的一份無卷須的黃瓜資源CG9192,該種質的卷須被側枝所替代,完全失去了攀援能力。我們推測該稀有表型是由稀有的遺傳變異引起的。通過基因組學、變異組學和轉錄組學的綜合分析,并應用稀有遺傳變異的分析策略,我們發(fā)現了控制黃瓜卷須發(fā)育的身份基因CsTEN,并揭示了黃瓜卷須的同源器官是側枝—這一曾經困擾達爾文的植物發(fā)育學謎團。本論文的主要結果如下：1.通過對變態(tài)卷須種質CG9192和正常卷須種質404的表型觀察和掃描電鏡分析,發(fā)現側枝是黃瓜卷須的同源器官,遺傳學研究表明變態(tài)卷須性狀由一個隱性單基因控制(CsTEN)。2.稀有SNP在黃瓜四個亞群的分布不均勻,印度亞群擁有的稀有SNP數目最高,占所有稀有SNP數目的81%,印證了印度是黃瓜的起源中心。應用稀有變異分析策略,結合轉錄組數據,發(fā)現了變態(tài)卷須種質CG9192的一個稀有SNP (rSNPl)對應著一個在黃瓜卷須里特異表達的基因Csa5G644520,推測該基因可能是卷須的身份基因。3.構建遺傳大群體,應用圖位克隆的方法將候選基因CsTEN定位區(qū)間縮小至16Kb(區(qū)間內只有一個基因),并通過與核心種質的基因組重測序序列比對,發(fā)現只有發(fā)現的rSNP1可以解釋變態(tài)卷須表型。針對rSNP1設計dCAPS標記,檢測了世界范圍內的、有卷須的1386份黃瓜種質,結果顯示該稀有變異僅存在于黃瓜種質CG9192中,從而從遺傳學上充分證明rSNP1所對應的基因Csa5G644520就是控制黃瓜卷須發(fā)育的基因CsTEN。4. CsTEN屬于TCP家族的CYC/TB1亞類,CsTEN上的稀有SNP發(fā)生在葫蘆科特有的保守結構域,該結構域不存在于已知的TCP蛋白中,該結構域是進化上新產生的一個結構域；煙草和酵母中的實驗表明,該稀有SNP顯著影響了CsTEN的轉錄激活活性。原位雜交分析進一步表明該CsTEN在黃瓜卷須里特異表達,是控制黃瓜卷須發(fā)育的身份基因。5.噴瓜是葫蘆科植物中唯一沒有卷須的植物,通過檢測葫蘆科卷須的身份基因TEN,發(fā)現噴瓜的TEN基因存在至少兩個以上的提前終止變異,使得噴瓜的TEN基因完全失去了功能。6.構建了正常卷須和變態(tài)卷須的近等基因系,并將這對近等基因系進行轉錄組測序,發(fā)現CsTEN抑制葉和花等的側生器官相關基因的表達,同時促進向觸性運動相關基因的表達。
[Abstract]:Tendril is one of the most important aspects of plant type research in cucurbitaceae, and it is also an important plant model organ to study the thixotropic movement of plants, and the complete sequencing of cucumber genome, transcriptome and variation group. This paper collected 3342 cucumber germplasm resources from all over the world and found the only cucumber CG9192 without tendrils. The tendrils of the germplasm were replaced by lateral branches and lost the ability to climb completely. We speculate that the rare phenotype is caused by rare genetic variation. Using the analysis strategy of rare genetic variation, we found the identity gene CsTEN that controls the development of tendrils in cucumber. It also reveals that the homologous organ of cucumber tendrils is lateral branches-a phytodevelopmental mystery that once troubled Darwin. The main results of this paper are as follows:. 1. Phenotypic observation and scanning electron microscope analysis of metamorphosed tendrils (CG9192) and normal tendrils (404). It was found that lateral branches were the homologous organs of cucumber tendrils. Genetic studies showed that metamorphosis of tendrils was controlled by a single recessive gene, CsTEN. 2. The distribution of rare SNP in four subpopulations of cucumber was not uniform. India subgroup has the highest number of rare SNP, accounting for 81% of all rare SNP, which confirms that India is the origin center of cucumber. A rare SNP rSNP of CG9192, a metamorphosis tendrils, was found to correspond to a gene Csa5G644520 specifically expressed in cucumber tendrils. It is speculated that this gene may be an identity gene of tendrils. A large genetic population was constructed, and the mapping method was used to narrow the mapping interval of candidate gene CsTEN to 16kb (there was only one gene in the region). The results showed that only the rSNP1 could explain the phenotype of abnormal tendrils. DCAPS markers were designed for rSNP1 and detected in the world. There were 1386 cucumber germplasms with tendrils. The results showed that the rare variation existed only in the cucumber germplasm CG9192. Therefore, it is fully proved from genetics that the gene Csa5G644520 corresponding to rSNP1 is the gene CsTEN.4which controls the development of tendrils in cucumber. CsTEN belongs to the CYC/TB1 subclass of the TCP family. Rare SNP on CsTEN occurs in the conserved domain of Cucurbitaceae, which does not exist in known TCP proteins. Experiments in tobacco and yeast showed that the rare SNP significantly affected the transcriptional activation activity of CsTEN. In situ hybridization analysis showed that the CsTEN was specifically expressed in the tendrils of cucumber. It is the identity gene that controls the development of cucumber tendrils. 5. Spray melon is the only plant without tendrils in Cucurbitaceae. The identity gene TEN of tendrils of Cucurbitaceae is detected. It was found that there were at least two early termination mutations in the TEN gene of Spoux melon, which completely lost the function of TEN gene. 6. The near-isogenic lines of normal tendrils and metamorphosed tendrils were constructed. CsTEN inhibited the expression of genes related to lateral organs in leaves and flowers, and promoted the expression of genes associated with thixotropism.
【學位授予單位】：中國農業(yè)科學院
【學位級別】：博士
【學位授予年份】：2016
【分類號】：S642.2

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