Molecular evolution of strigolactone signaling in the parasitic plant Striga hermonthica

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07102
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Nagoya University
• Principal Investigator: Tsuchiya Yuichiro 名古屋大学, トランスフォーマティブ生命分子研究所, 特任准教授 (00442989)
• Research Collaborator: McCourt Peter ; Duncan Holbrook-Smith ; TOH Shigeo
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ストリゴラクトン / シグナル伝達 / 寄生植物 / ストライガ

Outline of Final Research Achievements

Strigolactones (SLs) function as plant hormone that regulate various developmental processes including suppression of shoot branching. On the other hands, seed germination of a parasitic plant Striga hermonthica is stimulated by SLs exuded by host roots. In this study, we investigated the relationship between these two functions based on the genetic interaction of HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE2 ( HTL/KAI2)-mediated SL signaling pathway and light signaling pathway in Arabidopsis. We showed that HTL/KAI2 interact with SUPPRESSOR OF PHYA1 (SPA1), a negative regulator of light signaling, in SL-dependent manner, and this interaction lead SPA1 protein to degradation in planta. We transferred the knowledge to Striga with the discovery of small molecule antagonist of HTL/KAI2 that also inhibit SL-dependent germination of Striga. These results suggest that the evolution of SL pathway took place with its interaction with light signaling pathway in the parasitic plant.

Free Research Field

植物ケミカルバイオロジー