title: Differences in defence responses of Pinus contorta and Pinus banksiana to the mountain pine beetle fungal associate Grosmannia clavigera are affected by water deficit.
abstract: We tested the hypotheses that responses to the mountain pine beetle fungal associate Grosmannia clavigera will differ between the evolutionarily co-evolved host lodgepole pine (Pinus contorta var. latifolia) and the naïve host jack pine (Pinus banksiana) and that these responses will be influenced by water availability. G. clavigera inoculation resulted in more rapid stem lesion development in lodgepole than in jack pine; water deficit delayed lesion development in both species. Decreased hydraulic conductivity was observed in inoculated lodgepole pine seedlings, likely because of tracheid occlusion by fungal hyphae and/or metabolite accumulation. Drought but not inoculation significantly impacted bark abscisic acid levels. Jasmonic and salicylic acid were implicated in local and systemic responses of both species to G. clavigera, with salicylic acid appearing to play a greater role in jack pine response to G. clavigera than lodgepole pine. Water deficit increased constitutive levels and/or attenuated induced responses to G. clavigera for several monoterpenes in lodgepole but not jack pine. Instead, inoculation of well-watered but not water deficit jack pine resulted in a greater number of xylem resin ducts. These findings reveal mechanisms underlying differences in G. clavigera-induced responses between lodgepole and jack pine hosts, and how water availability modulates these responses.
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.|Department of Forestry and Horticulture, The Connecticut Agricultural Experiment Station, New Haven, CT, 06504-1106, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Arango-Velez
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.|Department of Plant Agriculture, University of Guelph, 4890 Victoria Av. N., PO Box 7000, Vineland Station, ON, L0R 2E0, Canada.
authors.forename: Walid
authors.initials: W
authors.lastname: El Kayal
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.|Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
authors.forename: Charles C J
authors.initials: CC
authors.lastname: Copeland
authors.affiliation: National Research Council of Canada, Saskatoon, SK, S7N 0W9, Canada.
authors.forename: L Irina
authors.initials: LI
authors.lastname: Zaharia
authors.affiliation: Department of Renewable Resources, University of Alberta, Edmonton, AB, T6E 2E3, Canada.
authors.forename: Inka
authors.initials: I
authors.lastname: Lusebrink
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
authors.forename: Janice E K
authors.initials: JE
authors.lastname: Cooke
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000818:Animals; D001517:Coleoptera / Q000382:microbiology*; D017753:Ecosystem; D005658:Fungi / Q000502:physiology*; D006813:Humidity; D028223:Pinus / Q000033:anatomy & histology / Q000276:immunology* / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000378:metabolism; D018547:Plant Stems / Q000502:physiology; D025341:Principal Component Analysis; D036226:Seedlings / Q000378:metabolism / Q000382:microbiology; D012987:Soil; D013997:Time Factors; D014197:Trees / Q000382:microbiology; D014867:Water / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D012987:Soil; D014867:Water; D000040:Abscisic Acid
keywords: blue-stain fungi; drought; isohydric; jasmonate; jasmonate-isoleucine; near isohydric; phenolic; polyphenolic bands; range expansion; salicylate