The correlation between the change of organelle localization and salt stress tolerance

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05603
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39020:Crop production science-related
• Research Institution: Kindai University
• Principal Investigator: Yamane Koji 近畿大学, 農学部, 准教授 (50580859)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: イネ / 三次元再構築 / 塩ストレス / 葉緑体 / ミトコンドリア / ペルオキシソーム

Outline of Final Research Achievements

We investigated the importance of the interaction between chloroplast, mitochondria, and peroxisome in mesophyll cells of rice under salt stress. The organelle interaction was evaluated to calculate membrane contact area (MCA) between the organelles using the salt tolerant cultivar of Pokkali and salt sensitive cultivar of Nipponbare. The MCA between the three organelles in both cultivars increased under salt stress. However, the form of mitochondria was different in both cultivars. In Pokkali, the form was stretched or annular, and the surface area of the mitochondria significantly increased under salt stress compared with that in Nipponbare. In addition, the stretched mitochondria in Pokkali had larger MCA compared with that in Nipponbare under salt stress. These results suggest that it is important for salt tolerance to change the form of mitochondria leading to the increase in the surface area and MCA between chloroplasts and peroxisomes under salt stress.

Free Research Field

超微形態学

Academic Significance and Societal Importance of the Research Achievements

本研究における学術的意義は，膜接触に着目して三次元的にオルガネラ間の協調関係を定量評価できた点である．さらに，耐塩性にはオルガネラの形状変化を伴った膜接触面積の増加が必須であることを明らかにした点も，学術的意義があると考える．具体的には，耐塩性品種のPokkaliでは，ミトコンドリアの形状を大きく伸び広がった形に変化させ，葉緑体やペルオキシソームとの膜接触面積の割合を増加させていた．このことから，耐塩性の獲得には，ミトコンドリアの形状変化に伴う膜接触面積の増加が重要であることが示唆でき，学術的に新しい知見であると考えられる．