Scots Pines With Tolerance to Melampsora pinitorqua and Diplodia sapinea Show Distinct Metabolic Profiles

Abstract

Diplodia sapinea causes Diplodia tip blight (DTB) and is recognised as an opportunistic necrotrophic pathogen affecting conifers. While DTB is associated with abiotic stress, the impact of biotic stress in the host on D. sapinea's lifestyle shift is unknown. Observed co-occurrences of D. sapinea and Melampsora pinitorqua, causing pine twisting rust on Scots pine (Pinus sylvestris), instigated an investigation into their interaction with and influence on the defence mechanisms of the host. We hypothesised that M. pinitorqua infections predispose the trees to D. sapinea by stressing the host and altering the shoot metabolites. Pines in a plantation were sampled over time to study pathogen biomass and host metabolites. Symptoms of both pathogens were consistent over years, and the preceding season's symptoms affected the metabolic profiles pre-infection and M. pinitorqua's proliferation. Symptoms of M. pinitorqua altered shoot metabolites more than fungal biomass, with co-symptomatic trees exhibiting elevated M. pinitorqua biomass. Specific phenolic compounds had a strong positive association with the shoot symptom x D. sapinea interaction. D. sapinea's biomass presymptoms was independent of previous disease symptoms and infection by M. pinitorqua. Some trees showed disease tolerance, with delayed rust infections and minimal DTB symptoms. Further investigations on this trait are needed.

Keywords

chemical defence; Diplodia tip blight; disease tolerance; Melampsora populnea; pine twisting rust; Pinus sylvestris; Sphaeropsis sapinea

Published in

Plant, Cell and Environment
2024
Publisher: WILEY

SLU Authors

• Stein Åslund, Matilda

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Zhang, Ke

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Castaño Soler, Carles

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Stenlid, Jan

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Elfstrand, Malin

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science

Publication identifier

• DOI: https://doi.org/10.1111/pce.15218

Permanent link to this page (URI)

https://res.slu.se/id/publ/133192