Systemic effects of Heterobasidion annosum on ferulic acid glucoside and lignin of presymptomatic ponderosa pine phloem, and potential effects on bark-beetle-associated fungi.
Concentrations of soluble phenolics and lignin in the phloem of ponderosa pines inoculated with the pathogen Heterobasidion annosum were assessed over a period of 2 years in a 35-year-old plantation in northern California, USA. The major effect of the pathogen on phloem-soluble phenolics consisted of a significant accumulation of ferulic acid glucoside: 503 +/- 27 microg/g fresh weight (FW), compared with 366 +/- 26 microg/g FW for mock-treated and 386 +/- 27 microg/g FW for control trees. Lignin content was negatively correlated with ferulic acid glucoside concentration, and there was an indication of lignin reduction in the cell walls of inoculated trees. Lignin had a negative effect on the in vitro growth of two common bark beetle fungal associates. Ceratocystiopsis brevicomi and Ophiostoma minus. For this reason it, is hypothesized that lower lignification may facilitate the growth of beetle-associated fungi, resulting in greater susceptibility of the presymptomatic host to bark beetle colonization.
Bonello
Pierluigi
P
Department of Plant Pathology, 1 Shields Ave, University of California, Davis, California 95616, USA. bonello.2@osu.edu
Storer
Andrew J
AJ
Gordon
Thomas R
TR
Wood
David L
DL
Heller
Werner
W
D000222:Adaptation, Physiological; D000818:Animals; D001487:Basidiomycota / Q000472:pathogenicity*; D001517:Coleoptera / Q000382:microbiology / Q000472:pathogenicity*; D003373:Coumaric Acids / Q000032:analysis*; D005247:Feeding Behavior; D005960:Glucosides / Q000032:analysis*; D008031:Lignin / Q000032:analysis*; D028223:Pinus / Q000737:chemistry* / Q000382:microbiology; D011157:Population Dynamics
D003373:Coumaric Acids; D005960:Glucosides; D008031:Lignin; C004999:ferulic acid