油棕果肉脂肪酸、维生素E组分含量及相关基因功能的分析

发布时间：2018-08-14 09:28

【摘要】：油棕(Elaeis guineensis),一种热带油料作物,从它的果肉中压榨出的棕榈油含量高达50%以上,在化工、食品和生物能源等众多产业中具有非常重要的经济价值。然而棕榈油作为食用植物油品质较差,其中接近一半以上的是饱和脂肪酸——棕榈酸,棕榈酸过多对人体健康不利。除了脂肪酸,油棕还富含天然维生素E,维生素E能够有效防止多不饱和脂肪酸的过氧化,作为植物油的附加值,也被越来越多的研究者广泛关注。现今,随着生物技术的快速发展,关于油棕脂肪酸和维生素E相关的研究工作陆续展开。本研究对海南椰子研究所油棕种质资源圃中161份油棕果肉脂肪酸组分和维生素E的含量进行了测定,对该油棕种质资源进行评价,获得了部分优异油棕种质,为挖掘优良基因、改良棕榈油品质等工作打下了基础。另外,本研究通过反向遗传学的研究方法,即在拟南芥中超表达油棕脂肪酸合成相关的FatB1,FatB2,FatB3和维生素E合成相关的HGGT,对这些基因的功能进行了初步的分析。得到的主要结果如下:1.161份不同单株油棕果肉的脂肪酸和维生素E含量均存在丰富且连续的变异,绝大部分性状都呈现出近正态分布,这为后期通过关联分析寻找影响这些性状遗传变异的工作奠定了基础。2.在野生型拟南芥中超表达油棕FATB家族的FatB1,FatB2,Fat B3基因,发现FatB1和FatB2的转基因株系的种子与野生型相比,棕榈酸含量分别提高了3.5倍和4.1倍,FatB3的转基因株系的种子与野生型相比,新产生了月桂酸和豆蔻酸,棕榈酸含量提高了1.2倍。推测油棕果肉棕榈酸的积累可能受到FatB1,FatB2和FatB3不同程度的影响,另外FatB3还促进了中链脂肪酸的生成。3.油棕HGGT基因在拟南芥中超表达,相对于野生型,新产生了生育三烯酚,维生素E的总量提高了38%~73%,新产生的α-生育三烯酚含量最高仅24 mg/kg。可见超表达油棕HGGT主要引起的是α-生育三烯酚的积累。相比于其他作物,超表达油棕HGGT基因的似乎对总维生素E和α-生育三烯酚含量影响有限。4.探究油棕果肉脂肪酸组分与维生素各类型E含量之间的相关性,经分析发现α-生育酚、总生育三烯酚和总维生素E均与油酸呈显著或极显著正相关,α-生育酚与棕榈酸呈显著负相关;δ-生育三烯酚、γ-生育三烯酚、总生育三烯酚和总维生素E均与总含油量呈极显著或显著正相关。表明获得集低棕榈酸、高油酸、高含油量以及高维生素E含量等众多优良的综合品质于一身的油棕种质资源是有可能的。
[Abstract]:Oil palm oil (Elaeis guineensis), a tropical oil crop, is squeezed out of its pulp by more than 50% palm oil, which is of great economic value in many industries, such as chemical industry, food industry and bioenergy industry. However, the quality of palm oil as edible vegetable oil is poor, more than half of which is saturated fatty acid-palmitic acid, too much palmitic acid is harmful to human health. In addition to fatty acids, oil palm is also rich in natural vitamin E, vitamin E can effectively prevent the peroxidation of polyunsaturated fatty acids, as the added value of vegetable oils, has been widely concerned by more and more researchers. Nowadays, with the rapid development of biotechnology, researches on oil palm fatty acids and vitamin E have been carried out one after another. In this study, 161 oil palm germplasm nursery samples from Hainan Coconut Research Institute were tested for fatty acid composition and vitamin E content in the flesh of oil palm, and some excellent oil palm germplasm were obtained. The improvement of palm oil quality and other work laid the foundation. In addition, the functions of these genes were preliminarily analyzed by reverse genetic methods, namely, FatB1, FatB2FATB3 and vitamin E synthesis related to fatty acid synthesis in Arabidopsis thaliana (Arabidopsis thaliana). The main results were as follows: the fatty acid and vitamin E contents of different plants were rich and continuous variation, and most of the characters were nearly normal distribution. This laid a foundation for the work of searching for genetic variation of these traits by association analysis in later stage. 2. 2. In wild Arabidopsis thaliana (Arabidopsis thaliana), the FatB1-FatB2FATB3 gene of oil palm FATB family was overexpressed. It was found that the palmitic acid content of transgenic lines of FatB1 and FatB2 increased 3.5 times and 4.1 times than that of wild type, respectively. Lauric acid and nutmeg acid were produced, palmitic acid content increased 1.2 times. It is suggested that the accumulation of palmitic acid in oil palm pulp may be affected by FatB1, FatB2 and FatB3, and that FatB3 also promotes the production of middle chain fatty acids. The oil palm HGGT gene was overexpressed in Arabidopsis thaliana. Compared with the wild type, it produced new fertility trienol, the total amount of vitamin E increased 38%, and the newly produced 伪 -fertility trienol content was only 24 mg / kg. It can be seen that the accumulation of 伪-fertility trienol is the main cause of overexpression of oil palm HGGT. Compared with other crops, overexpression of oil palm HGGT gene seems to have a limited effect on total vitamin E and 伪 -fertility trienol. To explore the correlation between fatty acid composition of oil palm pulp and vitamin E content, 伪 -tocopherol was found by analysis. Total fertility trienol and total vitamin E were significantly or extremely positively correlated with oleic acid, 伪 -tocopherol negatively correlated with palmitic acid, 未 -fertility trienol, 纬 -fertility trienol, and 伪 -tocopherol were negatively correlated with oleic acid. Total fertility trienol and total vitamin E were significantly or positively correlated with total oil content. It is possible to obtain oil palm germplasm resources with low palmitic acid, high oleic acid, high oil content and high vitamin E content.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S565.9

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