Endophyte-bacterial symbiosis promotes flower bud formation in strawberry

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19164
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 39:Agricultural and environmental biology and related fields
• Research Institution: Ibaraki University
• Principal Investigator: Narisawa Kazuhiko 茨城大学, 農学部, 教授 (90431650)
• Co-Investigator(Kenkyū-buntansha): 黒倉 健 宇都宮大学, 農学部, 准教授 (10650898) ; 西澤 智康 茨城大学, 農学部, 教授 (40722111)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 根部エンドファイト / イチゴ / 花芽誘導 / 菌類親和性バクテリア

Outline of Final Research Achievements

Runner seedlings of diploid wild strawberry plants were treated with DSE and cultivated under non-flower-inducing conditions. RNA was extracted from strawberries and analyzed using time-series transcriptome. As a result, expression of WRKY41, a gene whose expression is induced by bacterial infection, and WRKY75, a gene involved in phosphorus uptake, was induced in the roots and shoot apex by DSE. It was suggested that these genes were expressed throughout the plant by inoculation with DSE and were involved in flower induction.
Inoculation of soybean with DSE and its compatible bacteria promoted the number of nodules formed and the growth of soybean seedlings. It was presumed that this was due to increased production of metabolic substances such as flavonoids in the plant roots by inoculation with DSE.

Free Research Field

農学

Academic Significance and Societal Importance of the Research Achievements

近年、植物の環境応答やその仕組みに関する分子生理学的な研究が進んでいる。有用微生物であるDSEも植物に環境ストレス耐性を付与するなど様々な機能を付加できることが明らかになってきたが、DSEによる花芽形成誘導に関しては、本研究が初めてである。本研究による成果によって、高品質なイチゴ果実の周年収穫を可能とする持続的な栽培技術にもつながると考える。