2023 Fiscal Year Final Research Report

Analysis of the regulatory mechanism of leaf differentiation via repression of expression by AS2 and nucleolar proteins.

Research Project

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Project/Area Number	19K06730
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	Chubu University
Principal Investigator	Kojima Shoko 中部大学, 応用生物学部, 准教授 (10340209)
Co-Investigator(Kenkyū-buntansha)	高橋広夫金沢大学, 薬学系, 准教授 (30454367) 松本省吾名古屋大学, 生命農学研究科, 教授 (90241489)
Project Period (FY)	2019-04-01 – 2024-03-31
Keywords	エピジェネティック / 核小体 / AS2/LOBドメイン / DNAメチル化 / 発現制御 / シロイヌナズナ / 45S rDNA / 葉の発生・分化
Outline of Final Research Achievements	Arabidopsis ASYMMERIC LEAVES2 (AS2) is a gene that plays an important role in leaf development and differentiation; AS2 promotes adaxial cell differentiation of the leaf by repressing abaxial factors of the leaf primordia. In the present study, we analyzed the effects of nucleolar protein genes, NUCLEOLIN1 (NUC1) and RNA HELICASE10 (RH10) on AS2 function, because the localization of AS2 at the periphery of the nucleolus is important for its function. We found altered localization of AS2 protein and reduced levels of DNA methylation of 45S rDNA in as2, nuc1, rh10 mutants, that indicate perinucleolar localization of AS2 that requires normal nucleolar structure and/or its function. The localization pattern of the 45S rDNA foci was also altered in these mutants. These results indicate that perinucleolar regions function as scaffold for gene silencing.
Free Research Field	植物分子生物学
Academic Significance and Societal Importance of the Research Achievements	本研究では、植物の主要な光合成器官である葉の発生のメカニズムの一端を明らかにした。今回得られた研究成果は、植物が様々な環境変化に応答しながら発生する仕組みを理解した上で地球環境を維持するのに役立つと期待され、社会的な意義は大きい。また、本研究で植物固有のAS2/LOBファミリータンパク質の１つ、AS2が葉の発生において機能する際に必要は核小体周縁部への局在には、正常な核小体が必要であり、45S rDNAメチル化の維持を介したエピジェネティックな調節に関わることを世界に先駆けて示した。