Effect of Leptographium terebrantis inoculation and drought on oleoresin and soluble phenolic levels in plantation Pinus taeda
| Authors: | John K. Mensah, Mary Anne Sword Sayer, Ryan L. Nadel, Lori G. Eckhardt |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Southern Research Station |
| DOI: | https://doi.org/10.1016/j.funeco.2026.101507 |
| Source: | Fungal Ecology |
Abstract
The influence of Leptographium terebrantis stem infection on constitutive and induced oleoresin and soluble phenolics in terminal shoots was assessed in a Pinus taeda plantation using three inoculum densities. The pathogen causes wilt disease by invading and colonizing root xylem tissues. We observed three levels of P. taeda defense in response to L. terebrantis during a two-year period interrupted by drought. Normal carbon allocation to growth was maintained and constitutive oleoresin production was observed at low and medium inoculum densities, with oleoresin induction observed among the medium inoculum density trees. At the high inoculum level, oleoresin flow occurred at a level similar to the medium inoculum density trees and carbon allocation to growth was diminished. Terminal shoot phenolic concentration was unaffected by the pathogen. Our findings validate the view that simultaneous occurrence of wilt disease and drought reduces constitutive and induced defenses by interfering with carbon fixation and allocation to growth.