茉莉酸甲酯对葡萄植株不定根发育的影响

利用不同浓度的茉莉酸甲酯(MeJA)对葡萄组培植株进行处理,进而分析其生理及基因表达变化,结果表明MeJA能抑制植株不定根的分化和伸长,诱导根、茎、叶组织中的脱落酸(ABA)含量升高,但降低赤霉素(GA)、生长素(IAA)和细胞分裂素(ZR)的含量,且影响叶片中叶绿素代谢导致褪绿黄化。MeJA能诱导植物体内茉莉酸合成代谢基因表达进而提高内源茉莉酸的含量,诱导ABA合成代谢和信号路径中的基因表达,但是会抑制生长素、赤霉素、细胞分裂素、油菜素内酯合成代谢基因的表达,抑制了与根发育和延伸相关基因VvXET、VvEXPB2、VvEXPA7和VvWUS的表达,进而抑制不定根的发生,导致植物发育缓慢。因此,MeJA通过影响其他激素的合成代谢来调控它们在植物中的含量,导致内源激素不平衡影响植株发育,并调控植株根的发育状态,在不定根发育方面起负向调控作用。

Effects of MeJA on Adventitious Root Development of Grape Plants

Jasmonic acid is not only involved in plant stress resistance，but also can regulate fruit growth and development. However，little research has been done on the regulation of grape root development. In this study，we used three concentrations of MeJA to treat grapevine tissue culture，and analyzed the physiological and gene expression levels. The results showed that MeJA could inhibit adventitious roots development and elongation，increased abscisic acid（ABA）content in leaf，root，stem tissues，but decreased the contents of gibberelin（GA），auxin （IAA）and cytokinin（ZR），and also affected the metabolism of chlorophyll in leaves that led to leaf chlorosis. Moreover，jasmonic acid could induce the expression of jasmonic acid synthesis genes to further increase the content of endogenous jasmonic acid，and induce the expression of ABA synthesis genes and signal pathway. However，it could inhibit the expression of auxin，gibberellin，cytokinin，and brassinolide synthesis genes，especially，the expression of the adventitious root development and elongation-related genes VvXET，VvEXPB2，VvEXPA7 and VvWUS was inhibited，thereby inhibiting the growth of new roots，leading to slow plant development. Therefore，MeJA can affect the synthesis metabolism of other hormones to regulate their endogenous content in plants，leading to imbalance of endogenous hormones which affect plant development. MeJA plays a negative regulatory role in plant adventitious root development.