Novel function of FAB1 in secondary cell wall element secretion and cortical microtubule polymerisation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05962
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38060:Applied molecular and cellular biology-related
• Research Institution: Kyoto Prefectural University
• Principal Investigator: Tomoko Hirano 京都府立大学, 生命環境科学研究科, 准教授 (20724496)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: FAB1 / 根毛 / 二次細胞壁成分の輸送 / 後期エンドソーム / 表層微小管

Outline of Final Research Achievements

The three essential elements for the complex and specialised morphogenesis of plant cells such as root hairs, pollen tubes, trichomes, stomata and epidermal cells are the orientation of the cytoskeleton 'actin' and 'cortical microtubules', and the formation of 'secondary cell walls'. We found that phosphatidyl 3-phosphate 5-kinase, FAB1, is a molecule that simultaneously regulates both the polymerisation of cortical microtubules and the secretion of secondary cell wall components. However, "how does FAB1 assists in the microtubule polymerisation?" and "how the secondary cell wall components are secreted by the FAB1-endosomes?" remained unknown. This study elucidates the secretion mechanism of secondary cell wall components.

Free Research Field

植物分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

植物の細胞壁のうち，すべての細胞に存在する一次細胞壁は，柔軟性を持ち，細胞が成長する過程で拡大・伸長し，細胞のかたち作りを様々な機構で制御している．これに対し，二次細胞壁は，植物や植物細胞の形を維持したり，硬さや頑強さを与えたりする役割をもつ．したがって，植物の細胞分裂や形態形成において中心的に働く微小管の生成機構や，植物に頑強さを与え，かつ，伸長抑制に働くことで，形態形成を担う二次細胞壁の形成過程・機構を理解することは，真に植物の成長を理解することである．
また，我々が資源としている木質バイオマスの大半が二次細胞壁に由来するため，本研究は，応用的側面にも大きな意義も持つ．