Emerald ash borer (Agrilus planipennis) infestation bioassays and metabolic profiles of green ash (Fraxinus pennsylvanica) provide evidence for an induced host defensive response to larval infestation

Frontiers in Forests and Global Change

Forests and Global Change

A. Daniel Jones¹  Jeanne Romero-Severson²  Robert K. Stanley²  Kingsley Owusu Otoo²  Aletta Doran³  Julia Wolf³  Mary E. Mason⁴  David W. Carey⁴  Jennifer L. Koch⁴  Therese M. Poland⁵ 

[1] Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States;Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States;Holden Arboretum, Kirtland, OH, United States;Northern Research Station, U.S. Department of Agriculture Forest Service, Delaware, OH, United States;Northern Research Station, U.S. Department of Agriculture Forest Service, Lansing, MI, United States;

关键词: secoiridoid;    Agrilus planipennis;    Fraxinus pennsylvanica;    liquid chromatography-mass spectrometry (LCMS);    emerald ash borer infestation bioassay;    induced host defensive response;    Fraxinus pennsylvanica;    host-insect interaction;   

DOI  :  10.3389/ffgc.2023.1166421

 received in 2023-02-15, accepted in 2023-06-01,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionLarvae of the invasive emerald ash borer [EAB, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)], kill over 99% of green ash (Fraxinus pennsylvanica Marshall) trees they infest, yet a small percentage of green ash (“lingering ash”) survive years of heavy EAB attack. In the face of an ongoing invasion that threatens multiple North American Fraxinus species with extinction, any evidence for reproducible defensive responses in the native species merits investigation.MethodsWe evaluated the capacity of three families of green ash F1 progeny to kill EAB larvae when challenged in greenhouse studies by infestation with a uniform density of EAB eggs followed by dissection 8 weeks post-infestation and comparison of the host metabolomic profiles.ResultsThe mean proportions of host-killed larvae in the two families of F1 progeny from lingering ash parents were significantly higher than that of host-killed larvae in the family of F1 progeny from susceptible ash parents (p < 0.001). Untargeted metabolomics comparing F1 progeny in the quartile with the highest percent host-killed larvae (HHK) to F1 progeny in the quartile with the lowest percent host-killed larvae (LHK) and to the uninfested F1 progeny within each family revealed evidence for induced biochemical responses to EAB. Infested trees produced significantly higher levels of select secoiridoids than uninfested trees, and LHK progeny produced significantly higher levels of select secoiridoids than the HHK progeny. HHK progeny produced significantly higher abundances of three metabolites annotated as aromatic alkaloids than the LHK and uninfested individuals.DiscussionBased on these results, we hypothesize that green ash responds to EAB infestation. However, only certain trees have the genetic capacity to tailor a response that kills enough EAB larvae to prevent lethal damage to the vascular system. Rigorous tests of this hypothesis will require 15–20 years of additional crossing, phenotyping, and omics analyses. The results of this investigation will encourage the establishment and continuation of breeding programs that, in concert with biocontrol and management, could provide trees that slow, if not halt, the decimation of the Fraxinus gene pool. At the same time, ongoing work on host-insect interaction will contribute to our understanding of how forest trees recognize and defend themselves against phloem-feeding insects.

【 授权许可】

Unknown   
Copyright © 2023 Stanley, Carey, Mason, Doran, Wolf, Otoo, Poland, Koch, Jones and Romero-Severson.