Arabidopsis Transcription Factor TCP17Regulates Light Signaling Transduction And Auxin Biosynthesis

Light is an important environmental factor regulating plant development. Auxin is one of the most important plant hormones participating in many developmental processes. Here we demonstrate that TCP17, a novel transcription factor plays a vital role in regulating hypocotyl elongation, which is integrated with light signaling pathway and auxin biosynthesis. Our results show that overexpressing Arabidopsis transcription factor TCP17can induce elongation of hypocotyl in a light dependent manner. Our results suggeste that TCP17expression can be induced by light; by contrast, TCP17protein accumulates in dark. We find mat exposing dark grown seeding in light can change the expression of YUCCA5, the key factor controlling auxin biosynthesis, which is dependent on TCP17. Meanwhile overexpressing TCP17can induce the expression of YUCCA5in a protein biosynthesis independent way, and CHIP assay suggests that TCP17can directly bind to the promoter of YUCCA5. In conclusion, our research uncovered that TCP17may be an important factor linking light signaling pathway and auxin biosynthesis in promoting hypocotyl elongation.