Critical roles of autophagy and enzymatic ROS production in the regulation of tapetal programmed cell death in rice

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05562
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38060:Applied molecular and cellular biology-related
• Research Institution: Suwa University of Science
• Principal Investigator: KURUSU Takamitsu 公立諏訪東京理科大学, 工学部, 准教授 (50422499)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: オートファジー / 活性酸素種(ROS) / タペート層 / プログラム細胞死 / 花粉発達 / イネ / 転写ネットワーク / 葯分化

Outline of Final Research Achievements

We comprehensively analyzed the effect of autophagy disruption on gene expression profile during the tapetal PCD in rice anther development using high-throughput RNA sequencing. Expression of thousands of genes, including specific transcription factors and several proteases required for tapetal degradation, fluctuated synchronously at specific stages during tapetal PCD progression in the wild type anthers, while this fluctuation showed significant delay in the autophagy-deficient mutant Osatg7-1. The state of ROS accumulation was apparently changed and suppressed in the ROS mutant during anther development. The numbers of autophagosome-like structures were reduced in the tapetum of ROS mutant at stage 10 compared to that of control plants. These results suggest that redox signals contribute to anther development as well as promoting pollen maturation, and may be involved in the regulation of tapetal autophagy in rice.

Free Research Field

応用分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では、葯発達や花粉への栄養供給細胞であるタペート細胞のPCD過程において、オートファジー誘導やレドックスシグナルの重要性に着目し、遺伝子発現・ROS蓄積を介した時空間的オートファジー制御機構の解明を進め、PCD進行過程におけるROSシグナルとオートファジー機構の生理的意義・重要性を明らかにすることが出来た。本成果は，栽培イネの花粉発達の新たな仕組みの解明だけでなく，将来的にオートファジー制御による作物の細胞内有害物質の低減化への活用が期待される。