MAC3A和MAC3B參與在光影響的葉綠素生合成和植物下胚軸生長

Abstract

植物的光敏色素會通過調節下游基因的表達來控制多個光相關的生理過程,但關於光敏色素在光相關的基因剪接中扮演什麼作用知之甚少。MOS4-Associated Complex(MAC)是一個會與剪接體結合的高度保守的核蛋白複合物。前人的研究中發現,MAC 的核心亞基 MAC3A、MAC3B 和 MOS4 與組蛋白去乙烯化酶 HDA15能交互作用。HDA15 會參與調控光相關的葉綠素生物合成和下胚軸伸長。我們的研究發現,在黑暗下 MAC3A、MAC3B 和 MOS4 會負調節葉綠素生物合成及在遠紅光下會影響下胚軸的生長。此外,mac3a mac3b 雙突變體中光相關基因 HYH、HFR1、PRR7 和 PAPP5 的剪接在遠紅光下也發生了改變。綜合以上結果,我們的研究發現 MAC3A 和 MAC3B 可能通過調節光相關基因的剪接從而影響遠紅光下下胚軸的生長。

Phytochromes control multiple light-dependent physiological processes by regulating gene expression, but little is known about the roles of phytochromes in controlling pre-mRNA splicing in response to light. The MOS4-associated complex(MAC) is a highly conserved nuclear protein complex associated with the spliceosome. Previous studies indicate that the core subunits of MAC, MAC3A, MAC3B and MOS4, can interact with the histone deacetylase HDA15 involved in light dependent chlorophyll biosynthesis and hypocotyl elongation. In this study, we found that MAC3A, MAC3B and MOS4 negatively regulate chlorophyll biosynthesis in the dark and hypocotyl elongation under far-red light. In addition, the alternatively spliced transcripts of the light regulated genes, HYH, HFR1, PRR7 and PAPP5, are altered in the mac3a mac3b double mutant under far-red light. Taken together, our studies indicate that MAC3A and MAC3B may play an essential role in far red light regulated hypocotyl elongation through regulating the splicing of light regulated genes.