Elucidation of the endophytic microflora that affects the effect of biofertilizer and the genetic factors on the plant side that control it

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21267
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Yamada Tetsuya 東京農工大学, (連合)農学研究科(研究院), 教授 (20422511)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: バイオ肥料 / バチルス属プミルス種 / 接種効果 / イネ / 内生微生物叢 / メタゲノム解析

Outline of Final Research Achievements

In this study, the types and abundance of endophytic bacteria colonized in seed embryos after imbibition of 11 rice cultivars were estimated and those differences between cultivars were detected by using metagenomic analysis (microbiota analysis of 16S rRNA region). In addition, among the 11 rice cultivars, a high positive correlation was observed between the growth-promoting effect of seedlings by inoculation of the biofertilizer microorganism (Bacillus pumilus TUAT1 strain) to the imbibed seeds and the abundance of specific endophytic bacteria colonized in the embryo. Furthermore, the chromosomal regions containing genes that may be involved in both the abundance of endophytic bacteria and the effect of inoculation of the Bacillus pumilus TUAT1 strain were detected by genome-wide association analysis on 70 rice cultivars.

Free Research Field

植物遺伝育種学

Academic Significance and Societal Importance of the Research Achievements

本研究では、植物に定着する内生細菌の存在量とBacillus pumilus TUAT1株のような植物成長促進根圏細菌（PGPR）の接種効果との間に関連性があることを明らかにした。また、植物には内生細菌の存在量を制御し、PGPRの接種効果に影響を及ぼす遺伝子が存在することが示唆された。これらの知見は、PGPRを原料としたバイオ肥料の施用効果が作物の品種や栽培地域の違いによって異なることの原因を明らかにし、より安定的かつ高い効果が現れる品種や施用技術を開発するための研究に役立つと考えられる。また、そのような品種や技術の開発は、農業の脱炭素化による持続性向上に貢献することが期待される。