| influence of water deficit on the molecular responses of pinus contorta × pinus banksiana mature trees to infection by the mountain pine beetle fungal associate, grosmannia clavigera. | conifers exhibit a number of constitutive and induced mechanisms to defend against attack by pests and pathogens such as mountain pine beetle (dendroctonus ponderosae hopkins) and their fungal associates. ecological studies have demonstrated that stressed trees are more susceptible to attack by mountain pine beetle than their healthy counterparts. in this study, we tested the hypothesis that water deficit affects constitutive and induced responses of mature lodgepole pine × jack pine hybrids (pi ... | 2014 | 24319029 |
| differential effects of plant ontogeny and damage type on phloem and foliage monoterpenes in jack pine (pinus banksiana). | coniferous trees have both constitutive and inducible defences that deter or kill herbivores and pathogens. we investigated constitutive and induced monoterpene responses of jack pine (pinus banksiana lamb.) to a number of damage types: a fungal associate of the mountain pine beetle (dendroctonus ponderosae hopkins), grosmannia clavigera (robinson-jeffrey & r.w. davidson); two phytohormones, methyl jasmonate (mj) and methyl salicylate (ms); simulated herbivory; and mechanical wounding. we only i ... | 2012 | 22659460 |
| allometric exponents as a tool to study the influence of climate on the trade-off between primary and secondary growth in major north-eastern american tree species. | trees invest in both primary (e.g. height) and secondary (e.g. diameter) growth. the trade-off between these investments varies between species and changes with the tree growing environment. to better establish this trade-off, readily available allometric exponents relating height to diameter at breast height (γ(h,dbh)) and stem volume to diameter at breast height (α(v,dbh)) were simultaneously studied. | 2016 | 26975315 |
| inhibition of insect glutathione s-transferase (gst) by conifer extracts. | insecticide synergists biochemically inhibit insect metabolic enzyme activity and are used both to increase the effectiveness of insecticides and as a diagnostic tool for resistance mechanisms. considerable attention has been focused on identifying new synergists from phytochemicals with recognized biological activities, specifically enzyme inhibition. jack pine (pinus banksiana lamb.), black spruce (picea mariana (mill.) bsp.), balsam fir (abies balsamea (l.) mill.), and tamarack larch (larix l ... | 2014 | 25270601 |
| biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections. | leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. we hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. this hypothesis was supported, because across 127 sites along a 2,160-km gradient in north america individuals of picea glauca, picea mariana, pinus banksiana, and abies b ... | 2014 | 25225397 |
| antioxidant potential of bark extracts from boreal forest conifers. | the bark of boreal forest conifers has been traditionally used by native americans to treat various ailments and diseases. some of these diseases involve reactive oxygen species (ros) that can be prevented by the consumption of antioxidants such as phenolic compounds that can be found in medicinal plants. in this study, ultrasonic assisted extraction has been performed under various solvent conditions (water:ethanol mixtures) on the bark of seven boreal forest conifers used by native americans i ... | 2013 | 26784337 |
| direction of interaction between mountain pine beetle (dendroctonus ponderosae) and resource-sharing wood-boring beetles depends on plant parasite infection. | plant pathogens can have cascading consequences on insect herbivores, though whether they alter competition among resource-sharing insect herbivores is unknown. we experimentally tested whether the infection of a plant pathogen, the parasitic plant dwarf mistletoe (arceuthobium americanum), on jack pine (pinus banksiana) altered the competitive interactions among two groups of beetles sharing the same resources: wood-boring beetles (coleoptera: cerambycidae) and the invasive mountain pine beetle ... | 2016 | 26820567 |
| variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle. | the secondary compounds of pines (pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (coleoptera: curculionidae, scolytinae) that feed on sub-cortical tissues of hosts. jack pine (pinus banksiana) has a wide natural distribution range in north america (canada and usa) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (dendroctonus ponderosae), which has recently expanded it ... | 2015 | 26042134 |
| pheromone production by an invasive bark beetle varies with monoterpene composition of its naïve host. | the secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae) has recently expanded its range into forests of jack pine, pinus banksiana lamb., in western canada. we investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the prim ... | 2015 | 26014128 |
| chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem. | host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. we investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (dendroctonus ponderosae) (mpb) and beetle attraction in response to a historical (lodgepole pine, pinus contorta var. latifolia) and a novel (jack pine, pinus banksiana) hosts, as pheromones regulate the host colonization process. beetles emit the same pheromones from both ... | 2014 | 24400902 |
| mountain pine beetles colonizing historical and naive host trees are associated with a bacterial community highly enriched in genes contributing to terpene metabolism. | the mountain pine beetle, dendroctonus ponderosae, is a subcortical herbivore native to western north america that can kill healthy conifers by overcoming host tree defenses, which consist largely of high terpene concentrations. the mechanisms by which these beetles contend with toxic compounds are not well understood. here, we explore a component of the hypothesis that beetle-associated bacterial symbionts contribute to the ability of d. ponderosae to overcome tree defenses by assisting with te ... | 2013 | 23542624 |