RNAi-based pesticides against the hard-to-control spider mite, Tetranychus urticae

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02203
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: SUZUKI Takeshi 東京農工大学, (連合)農学研究科(研究院), 准教授 (60708311)
• Co-Investigator(Kenkyū-buntansha): レンゴロ ウレット 東京農工大学, 工学(系)研究科(研究院), 教授 (10304403)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: RNAi / dsRNA / 農薬 / 鋏角類 / ハダニ

Outline of Final Research Achievements

The objective of this study is development of next-generation pesticides using RNA interference (RNAi) induced by orally ingested double-stranded RNA (dsRNA) in the two-spotted spider mite (Tetranychus urticae), a hard-to-control agricultural pest. First, we found that this species is capable of sucking particles of less than 500 nm in diameter, which will contribute to the development of carriers to protect dsRNA from ultraviolet radiation and to control its retention in plants and mites. Next, we developed multiple methods to promote efficient oral delivery of dsRNA into mites for the RNAi screening, and found several potential target genes that showed lethal effects in T. urticae. Third, we clarified the molecular mechanism underlying the dsRNA-length-dependent RNAi effect in T. urticae.

Free Research Field

応用昆虫学

Academic Significance and Societal Importance of the Research Achievements

ナミハダニは，これまでに抵抗性発達が報告された農薬の数が節足動物の中で最多であり，防除が極めて困難な害虫である．そのため，従来とは根本的に異なる作用機構をもつ次世代農薬の開発が求められている．本研究は，RNA干渉（RNAi）を基盤とした次世代農薬の開発に向けた生物検定系を構築し，複数の標的候補遺伝子やRNAiのトリガーである二本鎖RNA（dsRNA）のプロセッシング機構を明らかにした．これら成果は，RNAiを基盤としたナミハダニ防除の実現可能性を示しただけでなく，鋏角類のモデル生物である本種の逆遺伝学的解析プラットフォームの構築にも資する．