富士苹果果实中突触小泡蛋白基因(MdVAMP)的克隆及其表达

花青素是植物中最广泛存在的次生代谢物之一,是不同颜色花和果实色泽的关键色素。花青苷通常在细胞质中合成,于液泡中积累。虽然花青苷的生物合成途径已被深入研究,但它们从细胞质到液泡的转运以及显示红色的机制仍然不清楚。本试验通过RACE技术成功克隆出富士苹果及其芽变中MdVAMP cDNA序列的总长度。该基因cDNA序列全长994 bp,具有660 bp的开放阅读框(ORF),编码219个氨基酸。同源性分析表明,MdVAMP基因与沙梨同源性最高。定量PCR结果表明,MdVAMP基因在‘长富2’苹果及芽变果实摘袋后表达趋势与其花青苷含量变化相一致,芽变果实中MdVAMP基因表达量和花青苷含量均显著高于‘长富2’苹果。进一步在不同富士品种中研究发现,MdVAMP基因表达水平与花青苷含量密切相关。亚细胞定位结果显示MdVAMP主要定位于细胞质。该研究表明,MdVAMP基因可能参与了花青苷的转运和积累,这为进一步研究苹果果皮着色和花青苷转运提供了一定的科学基础。

Cloning and Expression of Synaptobrevin Gene(MdVAMP)in the Fruit of Fuji Apple(Malus domestica)

Anthocyanins are one of the most widely existed secondary metabolites that make a major contribution to the colour and quality of fruits and flowers in plants.Anthocyanins biosynthesis pathway are localized in the cytosol and then they are rapidly transported into the vacuole for storage.Although the biosynthetic pathway of anthocyanin has been well studied,their transport mechanism from the cytosol to the vacuole still needs to better understand.In this study,the full length cDNA of MdVAMP was cloned from Fuji apple and its bud sports by rapid amplification of cDNA ends(RACE).The full-length of the MdVAMP gene was 994 bp,which contained a complete open reading frame encoding 219 amino acids.Phylogenetic analysis showed that MdVAMP gene shared the highest homology with pear.Quantitative PCR analysis showed that the expression profiles of MdVAMP gene was approximately consistent with the change tendency of anthocyanin content.However,the expression level of MdVAMP and anthocyanin content in bud sports were significantly higher than'Changfu2'apple.Furthermore,quantitative PCR analysis in different Fuji apple showed that the expression level of MdVAMP was sighificantly correlated to the content of anthocyanin.In addiction,subcellular localization assays showed that the MdVAMP protein was mainly located in cytosol.The results showed that MdVAMP gene could be involved in the transport and accumulation of anthocyanin,which provided a scientific basis for further studies anthocyanin accumulation in apple skin.