Evaluation of infection routes of microorganisms to seeds by pollinator insects and its adaptive significance.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19285
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Yamagata University
• Principal Investigator: Yokoyama Jun 山形大学, 理学部, 教授 (80272011)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 植物 / 種子 / 内生微生物 / 訪花昆虫 / 垂直感染 / 水平感染

Outline of Final Research Achievements

Microorganisms that infect plant seeds are expected to be transmitted horizontally by flower-visiting insects. However this possibility has not been confirmed. In this study, we investigated the microbiota in the seeds of annual plants with chasmogamous and cleistogamous flowers, and verified the infection route from flowers via flower visitors as a mechanism of seed infection.
Microorganisms were isolated from the seeds of two plant species and molecular identification was performed. Microorganisms that may affect plant growth were isolated. The microorganisms isolated from flower-visiting insects included genera obtained from the seeds of the target plants, suggesting the possibility of transmission by flower-visiting insects. It was suggested that endophytic microorganisms may be selected during the infection process from the plant body to the seeds. Infection experiments were performed, but no effect of promoting germination was observed.

Free Research Field

多様性生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では、種レベルまで同一の微生物を種子と訪花昆虫の両方から得ることができなかったが、属レベルで共通の微生物は複数得られ、一定の微生物が訪花昆虫を介して種子に感染する可能性が示されたのではないかと考えている。種子に訪花昆虫によってもたらされる微生物がいる可能性は、植物への微生物感染経路の新しい道筋を示しているとともに、植物にとって生育上利益のある微生物や、逆に不利益な病原性微生物の感染経路としても作用していると考えられるため、今後特に後者の感染経路としての訪花昆虫のコントロールが重要な意味を持つかもしれない。