Spatio-temporal analysis of the effect of excess pyrophosphate on plant development

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04803
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Tokyo Gakugei University
• Principal Investigator: FERJANI Ali 東京学芸大学, 教育学部, 准教授 (20530380)
• Research Collaborator: GUNJI shizuka ; ASAOKA mariko
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 植物 / 葉器官 / H+-PPase / fugu5変異体 / ピロリン酸 / 組織 / 補償作用 / 表皮細胞の単純化

Outline of Final Research Achievements

Pyrophosphate (PPi) is generated by biological reactions, and its removal is essential for proper cell functions. In plants, H+-PPase is responsible for the removal of PPi, and the H+-PPase loss-of-function mutant fugu5 over-accumulates PPi, and displays postgerminative developmental and growth defects. In this study, the various developmental abnormalities caused by excess PPi have been analyzed in a developmental stage, tissue, and cell type specific manner, in order to elucidate the role of H+-PPase in plant metabolism and developmental regulation. As a result, we demonstrated that the effect of excess PPi differs among leaf tissues, that the degradation of PPi within guard cells is essential for exerting normal stomatal function, and that temporary removal of PPi during the initial phase following seed germination is proved to be necessary and sufficient to recover all developmental abnormalities in fugu5 background.

Free Research Field

植物生理学・分子発生遺伝学

Academic Significance and Societal Importance of the Research Achievements

PPi分解酵素は植物のみならず、大腸菌からヒトまでの生物が持つ重要な酵素であり、その活性が失われると生存できないとされてきたため、従来、解析のめどが立っていなかった。PPiの存在の発見以来70年余経つが、教科書では未だに生体内におけるPPi分解酵素の役割は謎とされている。そのなかで研究代表者は、独自に単離したPPi分解酵素の機能欠損型fugu5変異体を使うことで、上記の通り、PPiの阻害メカニズムの全貌を多元的に明らかにし、植物の代謝と発生制御におけるH+-PPaseの役割の解明に成功した。今回得られた成果は、基礎科学的貢献のみならず、近い将来、教科書を塗り替えることになると期待している。