Elucidation of the role of lignin in the development of gravitropism and the maintenance of organ bending state

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22326
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: KAJITA SHINYA 東京農工大学, (連合)農学研究科(研究院), 教授 (40323753)
• Co-Investigator(Kenkyū-buntansha): 笠原 博幸 東京農工大学, (連合)農学研究科(研究院), 教授 (00342767) ; 堀川 祥生 東京農工大学, (連合)農学研究科(研究院), 准教授 (90637711)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: リグニン / クワ / 自然突然変異体 / 生合成

Outline of Final Research Achievements

The shape of plant cells and plant bodies are defined by the cell walls that covers outside of the cells. In this study, we aimed to clarify the role of lignin, a major chemical component of plant cell walls, in maintaining the bent state of tree organs by using SEKIZAISOU, a spontaneous mutant of mulberry with a tendency to droop branchlets, and its offspring as the main experimental materials.
As a result of the study, a frameshift mutation was found in the gene of cinnamyl alcohol dehydrogenase (CAD), which is involved in lignin biosynthesis, and it was revealed that the function of the gene was completely lost in SEKIZAISOU. Although the lignin structure of the cultivar was significantly altered, the drooping morphology was independent to the mutation of the CAD gene.

Free Research Field

木質科学

Academic Significance and Societal Importance of the Research Achievements

赤材桑の木材は、単に赤いという視覚的な特徴だけでなく、それに含まれるリグニンが科学的処理により分解しやすい特徴を持つ。木材を燃料や化成品の原料として利用する際、リグニンの加工性の優劣が加工効率やコストに大きく影響を与える。赤材桑自体の生理学的、形態学的な特徴に加え、その木材の化学的な特質を深く調べることは、木材の有効利用方法の開発に大きく貢献し、脱炭素社会の構築にも資するものである。