TY - JOUR T1 - Genetic variation in NIN1 and C/VIF1 genes is significantly associated with Populus angustifolia resistance to a galling herbivore, Pemphigus betae. JF - Journal of insect physiology Y1 - 2016 A1 - Zinkgraf,Matthew S A1 - Meneses,Nashelly A1 - Whitham,Thomas G A1 - Allan,Gerard J KW - Animals KW - Aphids KW - beta-Fructofuranosidase KW - Enzyme Inhibitors KW - Genes, Plant KW - Genetic Variation KW - Haplotypes KW - Herbivory KW - Plant Immunity KW - Plant Proteins KW - Plant Tumors KW - Polymorphism, Single Nucleotide KW - Populus AB -

The identification of genes associated with ecologically important traits provides information on the potential genetic mechanisms underlying the responses of an organism to its natural environment. In this study, we investigated the genetic basis of host plant resistance to the gall-inducing aphid, Pemphigus betae, in a natural population of 154 narrowleaf cottonwoods (Populus angustifolia). We surveyed genetic variation in two genes putatively involved in sink-source relations and a phenology gene that co-located in a previously identified quantitative trait locus for resistance to galling. Using a candidate gene approach, three major findings emerged. First, natural variation in tree resistance to galling was repeatable. Sampling of the same tree genotypes 20 years after the initial survey in 1986 show that 80% of the variation in resistance was due to genetic differences among individuals. Second, we identified significant associations at the single nucleotide polymorphism and haplotype levels between the plant neutral invertase gene NIN1 and tree resistance. Invertases are a class of sucrose hydrolyzing enzymes and play an important role in plant responses to biotic stress, including the establishment of nutrient sinks. These associations with NIN1 were driven by a single nucleotide polymorphism (NIN1_664) located in the second intron of the gene and in an orthologous sequence to two known regulatory elements. Third, haplotypes from an inhibitor of invertase (C/VIF1) were significantly associated with tree resistance. The identification of genetic variation in these two genes provides a starting point to understand the possible genetic mechanisms that contribute to tree resistance to gall formation. We also build on previous work demonstrating that genetic differences in sink-source relationships of the host influence the ability of P. betae to manipulate the flow of nutrients and induce a nutrient sink.

VL - 84 SN - 0022-1910 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26518288&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. ER - TY - JOUR T1 - The impacts of increasing drought on forest dynamics, structure, and biodiversity in the United States. JF - Global change biology Y1 - 2016 A1 - James S Clark A1 - Iverson,Louis A1 - Woodall,Christopher W A1 - Allen,Craig D A1 - Bell,David M A1 - Bragg,Don C A1 - D'Amato,Anthony W A1 - Davis,Frank W A1 - Hersh,Michelle H A1 - Ibanez,Ines A1 - Jackson,Stephen T A1 - Matthews,Stephen A1 - Pederson,Neil A1 - Peters,Matthew A1 - Schwartz,Mark W A1 - Waring,Kristen M A1 - Zimmermann,Niklaus E KW - biodiversity KW - Droughts KW - Ecosystem KW - Forests KW - Trees KW - United States AB -

We synthesize insights from current understanding of drought impacts at stand-to-biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand-level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, changes in composition and structure, and shifting range limits are widely observed. In the eastern US, the effects of increasing drought are becoming better understood at the level of individual trees, but this knowledge cannot yet be confidently translated to predictions of changing structure and diversity of forest stands. While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought. Throughout the continental United States, the combination of projected large climate-induced shifts in suitable habitat from modeling studies and limited potential for the rapid migration of tree populations suggests that changing tree and forest biogeography could substantially lag habitat shifts already underway. Forest management practices can partially ameliorate drought impacts through reductions in stand density, selection of drought-tolerant species and genotypes, artificial regeneration, and the development of multistructured stands. However, silvicultural treatments also could exacerbate drought impacts unless implemented with careful attention to site and stand characteristics. Gaps in our understanding should motivate new research on the effects of interactions involving climate and other species at the stand scale and how interactions and multiple responses are represented in models. This assessment indicates that, without a stronger empirical basis for drought impacts at the stand scale, more complex models may provide limited guidance.

VL - 22 SN - 1354-1013 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26898361&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 7 ER - TY - BOOK T1 - From genes to ecosystems: emerging concepts bridging ecological and evolutionary dynamics. Y1 - 2012 A1 - JK Bailey A1 - Schweitzer,JA A1 - Fitzpatrick,BM A1 - Genung,MA A1 - Pregitzer,CC A1 - M Zinkgraf A1 - TG Whitham A1 - Keith,A A1 - Reilly-Wapstra,JM A1 - Potts,BM A1 - Rehill,BJ A1 - LeRoy,CJ A1 - Fischer,DG A1 - Iason,GR A1 - Dicke,M A1 - Hartley,SE ED - Iason,GR ED - Dicke,M ED - Hartley,SE PB - Cambridge University Press CY - New York N1 - [Original String]:Bailey JK, Schweitzer JA, Úbeda F, Fitzpatrick BM, Genung MA, Pregitzer CC, Zinkgraf M, Whitham TG, Keith A, O’Reilly-Wapstra JM, Potts BM, Rehill BJ, LeRoy CJ, Fischer DG. 2012. From genes to ecosystems: emerging concepts bridging ecological and evolutionary dynamics. In Iason GR, Dicke M, Hartley SE, editors The ecology of plant secondary metabolites: from genes to global processes New York (NY): Cambridge University Press; p 269-286. ER - TY - JOUR T1 - A genetic basis for the manipulation of sink-source relationships by the galling aphid Pemphigus batae. JF - Oecologia Y1 - 2011 A1 - Compson,Zacchaeus G A1 - Larson,Katherine C A1 - Zinkgraf,Matthew S A1 - Whitham,Thomas G KW - Animals KW - Aphids KW - Carbon Radioisotopes KW - Ecosystem KW - Feeding Behavior KW - Host-Parasite Interactions KW - Phloem KW - Plant Leaves KW - Plant Shoots KW - Populus AB -

We examined how the galling aphid Pemphigus batae manipulates resource translocation patterns of resistant and susceptible narrowleaf cottonwood Populus angustifolia. Using carbon-14 ((14)C)-labeling experiments in common garden trials, five patterns emerged. First, although aphid galls on resistant and susceptible genotypes did not differ in their capacity to intercept assimilates exported from the leaf they occupied, aphids sequestered 5.8-fold more assimilates from surrounding leaves on susceptible tree genotypes compared to resistant genotypes. Second, gall sinks on the same side of a shoot as a labeled leaf were 3.4-fold stronger than gall sinks on the opposite side of a shoot, which agrees with patterns of vascular connections among leaves of the same shoot (orthostichy). Third, plant genetic-based traits accounted for 26% of the variation in sink strength of gall sinks and 41% of the variation in sink strength of a plant's own bud sinks. Fourth, tree susceptibility to aphid gall formation accounted for 63% of the variation in (14)C import, suggesting strong genetic control of sink-source relationships. Fifth, competition between two galls was observed on a susceptible but not a resistant tree. On the susceptible tree distal aphids intercepted 1.5-fold more (14)C from the occupied leaf than did basal aphids, but basal aphids compensated for the presence of a distal competitor by almost doubling import to the gall from surrounding leaves. These findings and others, aimed at identifying candidate genes for resistance, argue the importance of including plant genetics in future studies of the manipulation of translocation patterns by phytophageous insects.

VL - 167 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=21667296&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 3 ER - TY - JOUR T1 - Genetically-based trait variation within a foundation tree species influences a dominant bark lichen . JF - Fungal Ecology Y1 - 2011 A1 - Lamit,LJ A1 - MA Bowker A1 - LM Holeski A1 - Næsborg,RR A1 - Wooley,SC A1 - M Zinkgraf A1 - Lindroth,RL A1 - TG Whitham A1 - CA Gehring VL - 4 N1 - [Original String]:Lamit LJ, Bowker MA, Holeski LM, Næsborg RR, Wooley SC, Zinkgraf M, Lindroth RL, Whitham TG, Gehring CA. 2011. Genetically-based trait variation within a foundation tree species influences a dominant bark lichen . Fungal Ecology 4:103-109. ER - TY - JOUR T1 - Hybridization among foundation tree species influences the structure of associated understory plant communities JF - Botany-botanique Y1 - 2011 A1 - Lamit,LJ A1 - Wojtowicz,T A1 - Kovacs,Z A1 - Wooley,SC A1 - M Zinkgraf AB - Understanding how genetic identity influences community structure is a major focus in evolutionary ecology, yet few studies examine interactions among organisms in the same trophic level within this context. In a common garden containing trees from a hybrid system (S. Wats. × James), we tested the hypothesis that the structure of establishing understory plant communities is influenced by genetic differences among trees and explored foliar condensed tannins (CTs) and photosynthetically active radiation (PAR) as mechanisms. Several findings support our hypothesis: () Understory biomass and cover increase along the genetic gradient from to . () Along the same hybridization gradient, species richness decreases and species composition shifts. () foliar CT concentrations and PAR decrease from to . () Understory species richness increases with foliar CTs; however, biomass, cover, and composition show no relationship with CTs, and no understory variables correlate with PAR. () Structural equation modeling suggests that foliar CTs are a primary mechanism linking overstory tree genetics with understory richness. Using an experimental system dominated by naturally colonizing exotic species, this study demonstrates that a genetic gradient created by tree hybridization can influence understory plants.Pour l'écologie évolutive, la compréhension de l'influence de l'identité génétique sur la structure des communautés constitue un enjeu majeur; pourtant, il existe peu d'études ayant examiné les interactions entre les organismes occupant la même échelle trophique dans ce contexte. Dans un jardin commun comportant des arbres provenant d'un système hybride (S. Wats.× James), les auteurs ont vérifié l'hypothèse à l'effet que la structure de la mise en place des communautés végétales de sous bois se fait sous l'influence des différences génétiques entre les arbres, en utilisant comme mécanismes les tannins foliaires condensés (CTs) et les radiations photosynthétiquement actives (PAR). Plusieurs constatations supportent cette hypothèse. () La biomasse de sous bois et la couverture augmentent le long d'un gradient génétique, à partir du jusqu'au . () Le long du même gradient d'hybridation, la richesse en espèces diminue et la composition en espèces se déplace. () La teneur en CT foliaires et les PAR des diminuent du vers le . () La richesse en espèces du sous-bois augmente avec les CTs foliaires, cependant, la couverture et la composition de la neige ne montrent pas de relation avec les CTs, et aucune variable du sous-bois ne montre de corrélation avec les PAR. () La modélisation de l'équation structurale suggère que les CTs constituent un mécanisme primaire liant la génétique des arbres de la canopée avec la richesse en sous-étage. 08 l'aide d'un système expérimental dominé par la colonisation naturelle avec des espèces exotiques, cette étude démontre qu'un gradient génétique créé par l'hybridation des arbres peut influencer les plantes de sous-bois. VL - 89 UR - http://www.ingentaconnect.com/content/nrc/bot/2011/00000089/00000003/art00003 IS - 3 ER - TY - JOUR T1 - A dense linkage map of hybrid cottonwood (Populus fremontii x P. angustifolia) contributes to long-term ecological research and comparison mapping in a model forest tree. JF - Heredity Y1 - 2008 A1 - Woolbright,S A A1 - Difazio,S P A1 - Yin,T A1 - Martinsen,G D A1 - Zhang,X A1 - Allan,G J A1 - Whitham,T G A1 - Keim,P KW - Chimera KW - Chromosome Mapping KW - Ecology KW - Genetic Linkage KW - Genetic Markers KW - Genetics, Population KW - Genome, Plant KW - Linkage Disequilibrium KW - Models, Biological KW - Polymorphism, Restriction Fragment Length KW - Populus KW - Trees AB -

Cottonwoods are foundation riparian species, and hybridization among species is known to produce ecological effects at levels higher than the population, including effects on dependent species, communities and ecosystems. Because these patterns result from increased genetic variation in key cottonwood traits, novel applications of genetic tools (for example, QTL mapping) could be used to place broad-scale ecological research into a genomic perspective. In addition, linkage maps have been produced for numerous species within the genus, and, coupled with the recent publication of the Populus genome sequence, these maps present a unique opportunity for genome comparisons in a model system. Here, we conducted linkage analyses in order to (1) create a platform for QTL and candidate gene studies of ecologically important traits, (2) create a framework for chromosomal-scale perspectives of introgression in a natural population, and (3) enhance genome-wide comparisons using two previously unmapped species. We produced 246 backcross mapping (BC(1)) progeny by crossing a naturally occurring F(1) hybrid (Populus fremontii x P. angustifolia) to a pure P. angustifolia from the same population. Linkage analysis resulted in a dense linkage map of 541 AFLP and 111 SSR markers distributed across 19 linkage groups. These results compared favorably with other Populus linkage studies, and addition of SSR loci from the poplar genome project provided coarse alignment with the genome sequence. Preliminary applications of the data suggest that our map represents a useful framework for applying genomic research to ecological questions in a well-studied system, and has enhanced genome-wide comparisons in a model tree.

VL - 100 SN - 0018-067X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17895905&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1 ER -