阿拉伯芥FLC和MAF1與HDA9互作參與開花調控之功能性研究

Abstract

阿拉伯芥轉錄因子FLC是調控開花很重要的負調控因子，FLC會透過抑制下游的開花正調控因子FT和SOC1去抑制開花。阿拉伯芥有五個與FLC同源的蛋白，MAF1、MAF2、MAF3、MAF4和MAF5。這些MAF蛋白和FLC一樣，在抑制阿拉伯芥開花上扮演著重要的角色。阿拉伯芥HDA9是屬於RPD3/HDA1類型的組蛋白去乙醯化酵素，hda9的突變株會有早開花的現象。我們觀察到flc、maf1和hda9的突變株不論是在短日照或長日照都會有早開花的現象。經由檢測基因表現結果發現FT和SOC1會受到MAF1和HDA9的抑制，而且雙分子螢光互補實驗 (bimolecular fluorescence complementation assays) 和酵母雙雜交實驗（yeast two- hybrid assays）證實了FLC和MAF1都可以跟HDA9相互作用。綜合以上結果，HDA9可能會透過與FLC和MAF1相互作用去抑制FT和SOC1的表現而影響植物開花。

FLC is a key regulator of flowering in Arabidopsis thaliana. FLC inhibits flowering by repressing FT and SOC1 genes that promote flowering. There are five FLC clade members, MAF1, MAF2, MAF3, MAF4 and MAF5 in Arabidopsis. Like FLC, MAF1 to MAF5 also act as repressors of flowering. Arabidopsis HDA9 belongs to the RPD3/HDA1 histone deacetylase, and hda9 mutants have an early flowering phenotype. In this study, we analyzed the flowering phenotype of flc, maf1 and hda9 mutants. Compared with wild type plants, flc, maf1 and hda9 plants flowered earlier under both long-day or short-day conditions. In addition, the expression of FT and SOC1 was significantly increased in maf1 and hda9 plants. Further analysis indicated that HDA9 interacted with FLC and MAF1 in bimolecular fluorescence complementation and yeast two- hybrid assays. These results indicated that HDA9 may interact with FLC and MAF1 to repress the expression of FT and SOC1.