Pyrophosphate-Mediated Regulation of Plant Metabolism and Its Application in Modifying Plant Functions

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K05826
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38030:Applied biochemistry-related
• Research Institution: National Institute for Basic Biology
• Principal Investigator: Segami Shoji 基礎生物学研究所, 生物進化研究部門, 助教 (00765935)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: ピロリン酸 / 液胞 / プロトンポンプ / ピロホスファターゼ

Outline of Final Research Achievements

We verified that plants maintain optimal pyrophosphate concentrations in different tissues by utilizing two types of hydrolytic enzymes, V-PPase and sPPase, selectively. In columella cells at the root apex, ectopic expression of V-PPase led to a reduction in starch and enlargement of vacuoles, a phenomenon also observed in mutants lacking H+ transport activity. This suggests a physiological significance in maintaining low V-PPase expression for functional integrity. Regarding the enhanced V-PPase deficiency phenotype in aerial parts when NH4+ was not used as a nitrogen source, it was determined that no other hydrolytic enzymes besides V-PPase and sPPase were involved, and there were no changes in their expression levels. However, identifying the pathway of PPi production in the aerial parts remains unresolved and is a subject for future research.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

V-PPaseは液胞膜においてH+を輸送するポンプであり、その過剰発現により植物に有益な形質を付与することが多数報告されている。しかし、ピロリン酸の濃度を決定する因子であることも近年判明しており、その機能の本質的な理解はまだ十分ではない。本研究ではV-PPaseが例外的に少ない根端コルメラに注目し、V-PPase高発現がH+輸送活性の有無に依らず悪影響を及ぼす例を示した。当初の仮説を否定する結果も得られておりピロリン酸蓄積との関係を議論するにはさらなる解析が必要だが、コルメラの機能維持のための液胞膜タンパク質発現制御という側面を見出した。