Analyses of epigenetic regulation of plant meiosis and intercellular communication between germ and somatic cells

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H02181
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 39010:Science in plant genetics and breeding-related
• Research Institution: National Institute of Genetics
• Principal Investigator: Kenichi Nonomura 国立遺伝学研究所, 遺伝形質研究系, 准教授 (10291890)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 減数分裂 / 植物生殖 / イネ / Arogonaute / Small RNA / 品種改良 / エピジェネティクス

Outline of Final Research Achievements

Meiosis is a fundamental event for breeding by hybridization. It is known that meiosis-specific DNA/histone modification patterns influence frequencies and genomic positions of meiotic recombination. In this study, we analyzed molecular functions of two rice Argonaute proteins, both of which bind to small RNAs as guides. The results of this study suggest a possibility that either of two AGOs represses a gene required for pollen development during premeiotic and meiotic phases with anther-specific 21nucleotides (nt)-phasiRNAs, and further that another AGO regulates condensation of meiotic chromosomes with meiosis-specific 24nt-phasiRNAs.

Free Research Field

植物細胞遺伝学

Academic Significance and Societal Importance of the Research Achievements

減数分裂は交雑育種による品種改良の根本原理であり、減数分裂期に特有のDNAおよびヒストンの修飾パターンは、減数分裂組換えの頻度や位置に影響する。今回、2つのイネAGOタンパク質について解析を行い、一方は減数分裂に不必要な遺伝子の誤作動を防止する抑制機能、もう一方は減数分裂染色体に直接結合して染色体凝縮を制御する可能性が示唆された。遺伝子機能を欠損した変異体では減数分裂染色体の凝縮異常が認められたことから、減数分裂組換え頻度・位置の決定にAGO/sRNA複合体を介したクロマチン修飾機構が重要である可能性が示唆された。品種改良の効率向上に向けて学術的・社会的意義は大きいと考える。