Mechanisms regulating transcriptional activation and repression by gravitropic response in root and cotyledon

2016 Fiscal Year Final Research Report

• Project/Area Number: 26506016
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: 宇宙生命学
• Research Institution: Yokohama City University
• Principal Investigator: Kakei Yusuke 横浜市立大学, 木原生物学研究所, 特任助教 (50636727)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 重力屈性 / オーキシン / シロイヌナズナ

Outline of Final Research Achievements

Plant gravitropism is regulated by polar transport of auxin to the same direction as gravity. The subsequent molecular mechanism of the differential growth still remains to be elucidated. An auxin biomarker protein containing modified TIR1, DII region of Aux/IAA and FRET regions was developed to compare auxin concentration in shoot and root gravitropism. However, overexpression of the biomarker did not work well because of cell death. Next, we analyzed transcriptional changes caused by wide range of auxin concentrations. Inhibitors of auxin biosynthesis BBo and PPBo that target auxin synthase YUCCA were developed to decrease auxin concentration effectively. Arabidopsis and Mung bean were treated by gravity stimuli, several kinds of auxin and inhibitors. Interestingly, transcriptional auxin-responses after gravity stimuli were observed at non-bending tissue in addition to bending tissues. This result showed that auxin concentration is not the only regulator of differential growth.

Free Research Field

植物分子生理学