大量表現阿拉伯芥WRKY25基因影響鹽分逆境反應與生長發育

Abstract

在植物界中WRKY轉錄因子廣泛存在於植物特有之大基因家族轉錄因子的其中一員。在阿拉伯芥中存在著74個WRKY轉錄因子，而在其中一些WRKY轉錄因子參與植物生長發育、訊息傳遞及逆境反應之功能。WRKY轉錄因子可藉由結合至其下游基因之啟動子上的順式作用元件進而抑制或活化此下游基因。然而，至今植物裡的WRKY轉錄因子之功能及分子機制並未清楚。在此篇研究中，我探究WRKY轉錄因子WRKY25 參與鹽分逆境之反應、側根生長發育及開花過程之調控。鹽分及離層酸處理誘導WRKY25之表現。此外，與野生型阿拉伯芥相較起來，在WRKY25大量表現株中，側根生長受抑制且對鹽分逆境耐受性增加，同時還擁有提早開花的表現型。如此，WRKY25可能在鹽分逆境反應和植物生長發育中扮演一重要的角色。

WRKY transcription factors belong to one of the largest transcription factor families in plants. Arabidopsis hsa seventy-four WRKYs and some of which are involved in plant development, signal transduction and stress responses. WRKYs can activate or repress expression of the downstream target genes and these gene through the binding to the cis-acting element W-box. However, the functions and the molecular mechanism of most plant WRKYs are still unknown. In this study, I investigated one of the WRKY transcription factors, WRKY25, with respect to its functions in salt stress response, lateral root development and flowering process. Salt and abscisic acid induced WRKY25 expression. In addition,the WRKY25 over-expression lines are more tolerance to salt stress. Furthermore, over-expression of WRKY25 inhibits lateral root development and promotes early flowering. Thus, WRKY25 may play an improtant role in salt stress response and plant development in Arabidopsis.