Study on the mechanism of thermospermine-enhanced mRNA translation in plants

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06724
• 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: Okayama University
• Principal Investigator: Takahashi Taku 岡山大学, 自然科学学域, 教授 (20271710)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: シロイヌナズナ / ポリアミン / サーモスペルミン / 維管束 / mRNA翻訳

Outline of Final Research Achievements

Four mutants of Arabidopsis that are insensitive to high concentrations of thermospermine were isolated and named its1, 3, 7, and 11. Genetic experiments revealed that the genes responsible for its1, 3, 7, and 11, encode an RNA methyl transferase, an RNA splicing-related enzyme, an RNA-binding protein, and a pseudo-uridine synthase, respectively. These results suggest the involvement of RNA processing or modification in the action of thermospermine.
Furthermore, SAC51, a target of thermospermine-enhanced mRNA translation, was identified as the gene responsible for the sac503 mutation that suppresses the phenotype of a thermospermine-deficient mutant, acl5.

Free Research Field

植物分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

ポリアミンはあらゆる生き物がもつ低分子塩基性化合物で，多様な生理活性を持つ。シロイヌナズナの解析から，オーキシンによる維管束分化の誘導をポリアミンの１つであるサーモスペルミンが抑えるという機能を明らかにしたが，その作用機構は不明である。本研究では，サーモスペルミン非感受性変異株itsを単離し，its1, its3, its7, its11がそれぞれRNAメチル化酵素，RNAスプライシング関連タンパク，RNA結合タンパク，RNAシュードウリジン化酵素をコードする遺伝子に変異を持つことを突き止め，サーモスペルミンの作用にRNA修飾が深く関わることを明らかにした。