三种栽培棉籽油脂组成及相关基因表达分析

The oil composition and related genes analysis of three cultivated cotton seeds

[目的]棉籽油脂是植物油脂的重要来源,对其组成和含量的研究对提高棉籽油利用率以及棉花综合利用有重要作用。棉籽油脂肪酸合成途径受到多种相关酶的调节,明确棉花油脂代谢过程的一些相关酶基因的表达水平,不仅能够阐明棉籽油脂组成的分子基础,而且还对定向改造棉籽油组成、专用型棉花品种育种提供理论依据和指导。[方法]本文以3种栽培棉为材料,提取棉籽油进行粗脂肪定量,利用气相色谱分析(GC)脂肪酸组成和含量,利用qRT-PCR技术分析4个相关酶基因在胚珠中的表达水平。[结果]棉籽油主要脂肪酸成分为亚油酸(18∶2)、棕榈酸(16∶0)、油酸(18∶1)和硬脂酸(18∶0),含量最高的是亚油酸(18∶2),含量最低的是硬脂酸(18∶0)。表达分析表明,Δ12脂肪酸脱氢酶(FAD2)基因的表达量最高,其它3个酶基因的表达有一定的差异。[结论]本研究不仅比较了3种栽培棉籽脂肪酸组成和含量,而且还明确了其脂肪酸组成的分子遗传基础。

[Objective]Cottonseed oil is an important source of vegetable oil.The study of its composition and content plays an important role in improving cotton seed oil and cotton utilization.Cottonseed fatty acid synthesis pathway is regulated by a variety of related enzymes,knowing the expression level of these related enzyme genes in cottonseed oil metabolism process not only to clarify the molecular basis of cottonseed oil composition,but also provide theoretical basis and guidance to directly modify the cottonseed oil composition and cotton breeding.[Methods]The three kinds of cultivated cotton were used as materials to extract cottonseed oil for total fat quantification.The fatty acids composition and content of them were analyzed by gas chromatography(GC).The expression levels of four related enzymes in ovules were analyzed by qRT-PCR.[Results]The main fatty acids of cottonseed oil were linoleic acid(18:2),palmitic acid(16:0),oleic acid(18:1)and stearic acid(18:0),the highest content was linoleic acid(18:2),the lowest content was stearic acid(18:0).Expression analysis showed that the expression ofΔ12 dehydrogenase(FAD2)gene was the highest,while the expressions of other three enzymes had some differences.[Conclusion]The study not only compared the composition and content of fatty acids in three kinds of cottonseed cultivars,but also clarified the molecular genetic basis of its fatty acid synthesis.