pect1-4 shows growth retardation at low temperature due to downregulation of COP respiration

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K07392
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Saitama University
• Principal Investigator: NISHIDA IKUO 埼玉大学, 理工学研究科, 教授 (40189288)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 呼吸活性 / 低温成長 / リン脂質生合成の意義

Outline of Final Research Achievements

The pect1-4 mutant that exhibits a 26% residual activity of CDP-ethanolamine biosynthesis shows pleiotropic mutant phenotypes, such as growth retardation at low temperature or short-day conditions and early flowering. In this study, we demonstrated that pect1-4 mutation causes downregulation of COP respiratory capacity, which in turn causes the growth retardation at low temperature or short-day conditions. Overexpression of constitutively active AOX1a* in pect1-4 mutants fully resumed the COP respiratory capacity and recovered from the growth retardation. On the other hand, pect1-4 AOX1a* plants partially recovered from the early flowering phenotype. Taken together, our results suggested that the pect1-4 mutant exhibits the pleiotropic mutant phenotypes via a respiratory capacity-dependent stress pathway and a non-stress pathway.

Free Research Field

植物分子生理学

Academic Significance and Societal Importance of the Research Achievements

ホスファチジルエタノールアミン（PE)はミトコンドリアなどの細胞内小器官の膜を構成するリン脂質であるが、その生合成を完全に阻害すると、細胞が生存できず、さらなる研究を阻んでいた。われわれは、PE生合成活性が野生型の1/4まで低下したpect1-4変異株を用いることにより、ミトコンドリアの機能低下によってもたらされる変異は、呼吸に依存したストレス経路と、呼吸に依存しない非ストレス経路によって引き起こされることをあきらかにした。