Abstract:

Sugar will eventually be exported transporter （SWEET） is a key protein for plants， which plays an important role in plant sugar transport， reproduction and developnent， stress resistance， and interaction with pathogens. In this study， we used potted plantings of cassava SC9 as materials， designed the target gene region of Mesweet18 silencing in cassava， used virus-induced gene silencing （VIGS） technology to infect. qRT-PCR results showed that the expression of Mesweet18 in silencing plant were 46.80%，30.23%，21.12%， respectively， which were significantly down-regulated than the control. The results of chlorophyll and soluble sugar content in leaves showed that chlorophyll a， b and total content were decreased， sucrose and fructose contents increased significantly， while glucose content decreased slightly， which compared with the control. The study on molecular function of Mesweet18 in cassava laid a foundation for the molecular mechanism of sugar transporter SWEET in cassava.

Key words: cassava, SWEET transporter, VIGS, soluble sugar content

摘要：

糖转运蛋白（sugar will eventually be exported transporter，SWEET）在植物运输糖类、生殖和发育、逆境性、与病原体互作等方面发挥着重要作用。选择木薯糖转运蛋白Mesweet18基因沉默的靶基因区域，通过病毒诱导的基因沉默(virus-induced gene silencing，VIGS)技术注射木薯SC9的盆栽苗叶片。qRT-PCR结果表明，Mesweet18在沉默植株中的表达量显著下调，分别是对照的46.80%、30.23%、21.12%。叶片叶绿素和可溶性糖含量检测结果表明，与对照相比，叶绿素a、b和总含量均出现不同程度的下降，蔗糖和果糖含量显著增加，而葡萄糖含量出现轻微下降。研究Mesweet18在木薯中的分子功能，为深入研究糖转运蛋白SWEET在木薯中的分子机制奠定了基础。

关键词: 木薯, SWEET转运蛋白, VIGS, 可溶性糖含量