TY - JOUR T1 - Genetically based susceptibility to herbivory influences the ectomycorrhizal fungal communities of a foundation tree species. JF - The New phytologist Y1 - 2009 A1 - Sthultz,Christopher M A1 - Whitham,Thomas G A1 - Kennedy,Karla A1 - Deckert,Ron A1 - Gehring,Catherine A KW - Animals KW - DNA, Fungal KW - Ecosystem KW - Host-Pathogen Interactions KW - Models, Biological KW - Moths KW - Mycorrhizae KW - Pinus KW - Symbiosis AB -

Although recent research indicates that herbivores interact with plant-associated microbes in complex ways, few studies have examined these interactions using a community approach. For example, the impact of herbivory on the community structure of ectomycorrhizal fungi (EMF) is not well known. The influence of host plant genetics on EMF community composition is also poorly understood. We used a study system in which susceptibility to herbivory has a genetic basis and a 20-yr insect removal experiment to examine the influence of chronic herbivory and plant genetics on the EMF community structure of Pinus edulis. We compared EMF communities of herbivore resistant trees, herbivore susceptible trees and herbivore susceptible trees from which herbivores were experimentally removed at two dates 10 yr apart. In both years sampled, resistant and susceptible trees differed significantly in EMF community composition. After 10 yr and 20 yr of herbivore removal, the EMF communities of removal trees were similar to those of susceptible trees, but different from resistant trees. The EMF community composition was more strongly influenced by innate genetic differences in plant traits associated with resistance and susceptibility to herbivory than by indirect effects of herbivory on host plant relationships with ectomycorrhizal fungi.

VL - 184 SN - 0028-646X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=19761493&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 3 ER - TY - JOUR T1 - Environmental and genetic effects on the formation of ectomycorrhizal and arbuscular mycorrhizal associations in cottonwoods. JF - Oecologia Y1 - 2006 A1 - Gehring,Catherine A A1 - Mueller,Rebecca C A1 - Whitham,Thomas G KW - Altitude KW - Carbon KW - Hybridization, Genetic KW - Mycorrhizae KW - Nitrogen KW - Polymorphism, Restriction Fragment Length KW - Populus KW - Soil KW - Symbiosis KW - Utah KW - Water AB -

Although both environment and genetics have been shown to affect the mycorrhizal colonization of host plants, the impacts of these factors on hosts that can be dually colonized by both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi are less understood. We examined the influence of environment and host crosstype on the EM and AM colonization of cottonwoods (Populus angustifolia and natural hybrids) by comparing levels of colonization of trees growing in common gardens that differed in elevation and soil type. We also conducted a supplemental watering experiment to determine the influence of soil moisture on AM and EM colonization. Three patterns emerged. First, garden location had a significant impact on mycorrhizal colonization, such that EM colonization was 30% higher and AM colonization was 85% lower in the higher elevation garden than the lower elevation garden. Second, crosstype affected total (EM + AM) colonization, but did not affect EM or AM colonization. Similarly, a significant garden x crosstype interaction was found for total colonization, but not for EM or AM colonization. Third, experimental watering resulted in 33% higher EM colonization and 45% lower AM colonization, demonstrating that soil moisture was a major driver of the mycorrhizal differences observed between the gardens. We conclude that environment, particularly soil moisture, has a larger influence on colonization by AM versus EM fungi than host genetics, and suggest that environmental stress may be a major determinant of mycorrhizal colonization in dually colonized host plants.

VL - 149 SN - 0029-8549 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=16642319&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1 ER -