A histone modication-based synthetic circuit to engineer temporal gene expression in Arabidopsis floral meristems

2022 Fiscal Year Final Research Report

• Project/Area Number: 18H02465
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Nobutoshi Yamaguchi 奈良先端科学技術大学院大学, 先端科学技術研究科, 准教授 (90767899)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: シロイヌナズナ / 花発生 / エピゲノム / 遺伝子発現

Outline of Final Research Achievements

The AG regulates floral meristem termination by preventing maintenance of the histone modification H3K27me3 along the KNU coding sequence. At two days after AG binding, cell division has diluted the repressive mark H3K27me3, allowing activation of KNU transcription prior to floral meristem termination. However, how many other downstream genes are temporally regulated by this intrinsic epigenetic timer is remain unknown.

Here, we identify direct AG targets regulated through cell cycle-coupled H3K27me3 dilution in Arabidopsis thaliana. Expression of the targets occurred later in plants with longer H3K27me3-marked regions. We established a mathematical model to predict gene expression and manipulated temporal gene expression using the H3K27me3-marked del region from the KNU coding sequence. Our results suggest that AG controls the timing of expression of various target genes via cell cycle-coupled dilution of H3K27me3 for proper floral meristem termination and stamen development.

Free Research Field

植物生理・分子

Academic Significance and Societal Importance of the Research Achievements

本研究により、メチル基をもつヒストンの数と分化遺伝子の誘導時期を方程式にして、花の幹細胞の自己複製と分化のバランスを決める際に起こる仕組みを数学的に明らかにし、一般的な法則を見出しました。この法則に従って、メチル基をもつヒストンの数を人為的に増やすと、方程式で計算される時期に分化遺伝子が誘導される実証実験にも成功しました。植物の幹細胞の自己複製と分化の普遍的な仕組みを知るだけでなく、その仕組みを有効に使って農業や園芸の分野で利用していくうえでも大きく貢献すると期待されます。