Functional characterization of novel transcription factors that regulate distribution of cortical microtubules in wood fibers in poplar

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K18734
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Wood science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Takata Naoki 国立研究開発法人森林研究・整備機構, 森林総合研究所 森林バイオ研究センター, 主任研究員 等 (90605544)
• Research Collaborator: Awano Tatsuya ; Yamagishi Yusuke ; Tobimatsu Yuki ; Suzuki Shiro ; Lam Pui Ying
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 組織構造 / 表層微小管 / 二次壁 / 木部繊維 / 転写フィードバックループ

Outline of Final Research Achievements

In the present study, we characterized transcription factors, TF26 and TF26b, which were identified as novel regulators of cortical microtubule distribution in poplar. TF26 and the paralogous gene, TF26b, were preferentially expressed in the xylem tissues of poplar. Overexpression of TF26 enhanced cell wall formation in wood fiber cells. We generated double knockout poplars, tf26 tf26b. Histological analysis of xylem tissues showed that secondary cell wall of wood fibers was depressed in the knockout mutants. Microarray analysis and quantitative real-time PCR analysis using TF26 overexpressors and double knockout mutants demonstrated that TF26 and TF26b form a positive transcriptional feedback loop with NST/SND orthologues, master regulators of secondary cell wall formation in wood fibers.

Free Research Field

樹木分子生物学

Academic Significance and Societal Importance of the Research Achievements

本研究で同定した転写因子（TF26遺伝子およびTF26b遺伝子）は、木部繊維の二次壁形成のマスター転写因子NST/SND遺伝子（VNS09およびVNS10）と正の転写フィードバックループを形成している。新たに発見した本制御機構は、木部繊維が二次壁を厚く堆積するためのシステムであると推察される。本研究成果により、支持細胞（木部繊維）が巨大な樹体を支えるために細胞壁を厚く発達させ物理的強度を獲得する分子メカニズムの一端を明らかにすることができた。