甘蓝型油菜种子发育过程中油脂积累动态及关键基因的表达差异分析

发布时间：2018-05-13 15:13

本文选题：甘蓝型油菜 + 含油量　；参考：《西南大学》2017年硕士论文

【摘要】：油菜的主要用途是收籽榨油,其种子含油量严重影响着油菜的生产效益。当前我国油菜的生产状况迫切需要通过提高种子的含油量来提高油菜的产油率,以适应国内外市场的需求。因此油菜高含油量育种已成为油菜育种工作者的主要目标之一。目前,关于油菜种子油脂的生物合成规律及调控分子机制的研究还未完全透彻,针对不同含油量的甘蓝型油菜之间油脂积累差异及油脂合成过程中相关基因的表达差异的研究甚少。本研究以具有不同遗传背景的甘蓝型油菜4个高油品系和3个低油品系为试验材料,利用残余法测定各品系种子发育过程中7个时期的含油量,分析油脂积累动态及其差异;同时利用实时荧光定量PCR技术,比较5个参与油脂生物合成的关键编码酶基因(ACCase、DGAT1、DGAT2、FatA、FatB)及1个转录因子WRI1在油菜种子发育过程中的表达模式及表达差异,探讨甘蓝型油菜油脂积累及其与关键基因表达的关系,以期为油菜含油量的遗传改良以及高含油量育种提供理论依据,促进油菜种质资源创新和新品种的选育。主要研究结果如下:1.对高低油品系种子含油量积累动态及差异的研究表明:(1)4个具有不同遗传背景的高含油量品系种子发育过程中油脂积累动态基本一致。在种子发育早期油脂积累比较缓慢,开花后25d种子的含油量仅占成熟种子的13.8%~21.4%。开花后26~35d是油脂积累的快速时期,在开花后35d种子的含油量即达到成熟种子的82.9%~94.5%。开花后36~45d种子油脂积累速度减慢,在成熟期油脂含量达到最大值。含油量在高油品系中的表现具有一致性,且高含油量的形成与含油量快速积累时期的持续时间有密切关系。(2)高油品系与低油品系之间,油脂积累差异最显著的时期是在种子含油量快速积累时期(开花后25~35d),高油品系油脂积累速率明显大于低油品系,很大程度上决定了不同油菜品系间种子含油量的差异。在开花后36~45d含油量积累量变小,高油品系表现为正向积累,低油品系表现为负积累,也是造成高低油油菜品系间最终含油量差异的重要原因之一。2.对高低油品系种子油脂合成途径关键基因的表达分析表明:(1)高油品系间ACCase、FatA、WRI1基因的表达模式相近,具有不同遗传背景的高油品系在主要基因表达上具有较好的一致性,其中FatA、WRI1基因的表达动态与油脂积累动态基本一致。(2)高油品系和低油品系之间,大部分基因在表达模式或表达水平上存在较大差异,但并不是所有基因在高油品系中均高水平表达。整体而言,ACCase、FatA基因在高油品系种子发育过程中表达水平明显比低油品系高,与含油量的形成密切相关,在一定程度上对高油的形成起着决定性作用。DGAT2基因主要种子发育后期起作用,虽对含油量的形成无决定性作用,但可以影响后期油脂的转化而间接影响含油量的高低;WRI1、FatB基因在低油材料中的表达明显比高油品系高,对油脂的积累无积极作用,不是油菜种子高油分形成的决定因素。3.油脂合成关键基因与含油量的相关性分析表明,在低油品系中,基因的表达与含油量的相互关系表现一致,种子成油机制较单一,而高油品系中,部分基因的表达与含油量的相互关系表现不一致,存在多种作用机制,种子高含油量的形成机制更为复杂;FatB和WRI1与含油量的关系表现为负相关,说明这两个基因的高表达对油脂积累无积极作用,是通过调控和影响其他基因而发挥作用。
[Abstract]:The main use of rapeseed is to extract oil from seeds, and its seed oil content seriously affects the production efficiency of rape. At present, the production status of rapeseed in China is urgently needed to improve the oil production rate of Rapeseed by raising the oil content of the seeds in order to meet the demand at home and abroad. Therefore, high oil content breeding in rape has become the main part of the rape breeding workers. At present, the research on the biosynthesis law and the regulation molecular mechanism of rape seed oil is still not thoroughly studied. There are few studies on the difference of oil accumulation and the expression of related genes in the process of oil synthesis in different oil-bearing Brassica napus. This research is based on 4 Brassica napus with different genetic background. A high oil product line and 3 low oil products were used as experimental materials. The oil content in the 7 periods of seed development in each line was measured by residual method, and the oil accumulation dynamics and its difference were analyzed. At the same time, 5 key coding enzyme genes (ACCase, DGAT1, DGAT2, FatA, FatB) and 1 rotation were compared by real-time fluorescence quantitative PCR technology. The relationship between the accumulation of oil and the expression of key genes in Brassica napus and its relationship with the key gene expression in the process of rape seed development was recorded by factor WRI1, in order to provide a theoretical basis for the genetic improvement of oil content in rape and the breeding of high oil content, and to promote the innovation of the germplasm resources and the selection of new varieties. 1. studies on the accumulation dynamics and differences of oil content in high and low oil lines showed that: (1) the accumulation dynamics of oil in the seed development process of 4 high oil content lines with different genetic backgrounds was basically consistent. The accumulation of oil in the early stage of seed development was slow, and the oil content of 25d seeds after flowering accounted for only 2 after the flowering of the mature seed. 6~35d is a rapid period of oil accumulation. After the flowering of 35d seeds after flowering, the accumulation of oil in 36~45d seeds decreased and the oil content reached the maximum at maturity. The oil content in the high oil system was consistent, and the formation of high oil content and the period of rapid accumulation of oil content were in the period of rapid accumulation of oil. 2. (2) the most significant difference in oil accumulation between high oil product line and low oil product line is in the period of rapid accumulation of oil content in the period of seed oil accumulation (after flowering 25~35d), the accumulation rate of oil in high oil line is obviously greater than that of low oil, which largely determines the difference in oil content between different strains of rape. After flowering, 3 The accumulation of oil content in 6~45d is small, the high oil product line is positive accumulation, the low oil product line is negative accumulation, and it is one of the important reasons for the difference of the final oil content among the high and low oil dishes. The expression of the key genes of the seed oil synthesis pathway of the high oil and low oil lines.2.: (1) the table of the ACCase, FatA, WRI1 gene among the high oil lines. The high oil lines with different genetic backgrounds have good consistency in the main gene expression, and the dynamic expression of FatA and WRI1 genes is basically consistent with the dynamic accumulation of oil. (2) most of the genes are different in the expression pattern or expression level between high oil and low oil lines, but not all the bases. As a whole, the expression level of ACCase and FatA genes in the seed development of high oil lines is obviously higher than that of low oil, which is closely related to the formation of oil content. To a certain extent, it plays a decisive role in the formation of high oil in the late development of the.DGAT2 gene, although the oil content is in the oil content. It has no decisive effect, but it can affect the transformation of late oil and influence the oil content indirectly. WRI1, the expression of FatB gene in low oil material is obviously higher than that of high oil, it has no positive effect on the accumulation of oil, it is not a decisive factor for the formation of high oil content in rapeseed seed,.3. oil synthesis key gene and the correlation of oil content. The analysis shows that the relationship between gene expression and oil content is consistent in low oil products, and the mechanism of seed oil formation is single, and the relationship between the expression of some genes and oil content in high oil products is not consistent, there are many mechanisms of action, the formation mechanism of high oil content is more complex; the relationship between FatB and WRI1 and oil content is related. The negative correlation showed that the high expression of these two genes had no positive effect on lipid accumulation, and played a role in regulating and affecting other genes.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S565.4

【参考文献】