花生ω-3△~(15)-脂肪酸脱氧酶基因AhFAD3A的克隆及其表达

花生油中的α-亚麻酸含量在不同种质资源中存在着差异,与籽仁的不同发育时期也密切相关。本研究通过生物信息学分析并利用RACE的方法,从萌发的花生子叶中克隆了一个参与花生α-亚麻酸合成的ω-3△15-脂肪酸脱氢酶基因,命名为AhFAD3A。利用荧光定量PCR分别比较分析了AhFAD3A和Ah FAD8基因在花生不同组织、籽仁发育不同阶段、萌发过程中的表达特征,结果表明:AhFAD3A基因主要在花期的叶片组织和根部、籽仁形成期表达,在其它发育阶段该基因的表达量比较低,证实该基因的表达与花生籽仁中α-亚麻酸的形成呈正相关;AhFAD8基因在花生的整个生育阶段的绿色组织中表达、非光合组织中几乎不表达。以上研究结果为进一步确定AhFAD3A基因的功能、表达调控及其与花生籽仁中α-亚麻酸形成的关系提供了研究基础。

Cloning and expression characteristics of one ω-3 cis 15 fatty acid dehydrogenase gene AhFAD3A in Arachis hypogaea L.

 The content of α-linolenic acid varied in different germplasm resources and different seed developmental stages in peanut oil. Oneα-linolenic acid synthesis related gene ω-3⊿15 fatty acid dehydrogenase gene, AhFAD3A was cloned from cotyledonary tissues of peanut germinating seeds using RACE and bioinformatics analysis. Its expression patterns were analyzed in different tissues and different period of seed developmental stages by the fluorescence quantitative real-time PCR method between two α- linolenic acid synthesis genes, AhFAD3A and AhFAD8. The results showed that: AhFAD3A gene was mainly expressed in leaf, root and young seed tissue during the period of flowering, and relatively low expression was found in the other developmental stages. This result verified that the gene expression was positively correlated to the formation of α-linolenic acid in seed. AhFAD8A gene was expressed in the green tissue during the whole growth stage of peanut, not detected in non optical tissues. These results laid a foundation for further research in determining the function of AhFAD3A gene, its expression regulation and its relationship with the formation ofα-linolenic acid in seed.