Analysis of calcium signaling in vegetative growth and reproduction

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06704
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Kyoto University
• Principal Investigator: IWANO Megumi 京都大学, 生命科学研究科, 研究員 (50160130)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: カルシウム情報伝達系 / ゼニゴケ / カルシウムチャネル / ゲノム編集株 / 細胞増殖

Outline of Final Research Achievements

MID1-COMPLEMENTING ACTIVITY (MCA) is a land plant-specific Ca2+ signaling component involved in response to mechanical stimuli. In rice and maize, MCA is essential for growth and development. However, how MCA mediates cell proliferation and differentiation via Ca2+ signaling remains unknown. In this study, we showed that a Marchantia polymorpha MCA, MpMCA was highly expressed in actively-dividing regions. In vivo Ca2+ imaging revealed that MpMCA was required for the maintenance of proper [Ca2+]cyt at the apical notch, the egg cells, and the antheridium cells. Mpmca mutant plants showed severe cell proliferation defects in thalli, gametangiophores, and gametangia, resulting in their abnormal development and unsuccessful fertilization. Expression of the Arabidopsis MCA1 gene complemented most defects in the growth of Mpmca mutant. Our findings indicate that MpMCA is an evolutionarily conserved Ca2+ signaling component regulating the development across the life cycle in land plants.

Free Research Field

植物分子生理学

Academic Significance and Societal Importance of the Research Achievements

植物は低温、乾燥、病原菌などの環境ストレスに応答して細胞内カルシウム濃度を上昇させ防御遺伝子の発現を誘導する。この機構については広く研究が進み、それに関わるカルシウムシグナル伝達系の分子実体も明らかになってきた。しかし、植物の成長・発達過程の細胞増殖・分化を制御するカルシウムシグナル伝達系の実体については研究が進んでいない。本研究では、生活史の大半を半数体で過ごすゼニゴケを利用したカルシウムイメージング系を構築し、生理学的・分子生物学的解析を行うことでMpMCAが細胞増殖・有性生殖のカルシウムシグナル伝達系で機能する分子であり、MCAの機能が陸上植物で保存されていることを明らかにした。