Publications

water stress-induced xylem hydraulic failure is a causal factor of tree mortality in beech and poplar.	extreme water stress episodes induce tree mortality, but the physiological mechanisms causing tree death are still poorly understood. this study tests the hypothesis that a potted tree's ability to survive extreme monotonic water stress is determined by the cavitation resistance of its xylem tissue.	2013	24081280
separation and purification of bioactive botrallin and tmc-264 by a combination of hsccc and semi-preparative hplc from endophytic fungus hyalodendriella sp. ponipodef12.	two dibenzo-α-pyrones, botrallin (1) and tmc-264 (2) were preparatively separated from crude ethyl acetate extract of the endophytic fungus hyalodendriella sp. ponipodef12, which was isolated from the hybrid 'neva' of populus deltoides marsh × p. nigra l. using a combination of high-speed counter-current chromatography (hsccc) and semi-preparative hplc. botrallin (1) with 74.73% of purity and tmc-264 (2) with 82.29% of purity were obtained through hsccc by employing a solvent system containing n ...	2014	24898177
enhanced production of botrallin and tmc-264 with in situ macroporous resin adsorption in mycelial liquid culture of the endophytic fungus hyalodendriella sp. ponipodef12.	hyalodendriella sp. ponipodef12, an endophytic fungus from the hybrid "neva" of populus deltoides × p. nigra, is a high producer of the bioactive dibenzo-α-pyrones botrallin and tmc-264. however, both the botrallin and tmc-264 produced by hyalodendriella sp. ponipodef12 were retained as both intracellular and extracellular products. the aim of this study was to evaluate an in situ macroporous resin adsorption for enhancement of botrallin and tmc-264 production in mycelial liquid culture of hyalo ...	2014	25211003
poplar pdc3h17 and pdc3h18 are direct targets of pdmyb3 and pdmyb21, and positively regulate secondary wall formation in arabidopsis and poplar.	wood biomass is mainly made of secondary cell walls, whose formation is controlled by a multilevel network. the tandem ccch zinc finger (tzf) proteins involved in plant secondary wall formation are poorly understood. two tzf genes, pdc3h17 and pdc3h18, were isolated from populus deltoides and functionally characterized in escherichia coli, tobacco, arabidopsis and poplar. pdc3h17 and pdc3h18 are predominantly expressed in cells of developing wood, and the proteins they encode are targeted to cyt ...	2014	24786865
host selection and probing behavior of the poplar aphid chaitophorus leucomelas (sternorrhyncha: aphididae) on two poplar hybrids with contrasting susceptibility to aphids.	poplars are frequently attacked by aphids. the differential susceptibility of poplar hybrids to the aphid chaitophorus leucomelas koch (sternorrhyncha: aphididae) has been described, but the mechanism underlying this pattern is unknown. this work tested the hypothesis that poplar resistance to this aphid is associated with the presence of volatiles and secondary plant compounds that affect host selection and feeding behavior. this hypothesis was tested by studying the host choice and feeding beh ...	2014	24665710
newly identified helper bacteria stimulate ectomycorrhizal formation in populus.	mycorrhiza helper bacteria (mhb) are known to increase host root colonization by mycorrhizal fungi but the molecular mechanisms and potential tripartite interactions are poorly understood. through an effort to study populus microbiome, we isolated 21 pseudomonas strains from native populus deltoides roots. these bacterial isolates were characterized and screened for mhb effectiveness on the populus-laccaria system. two additional pseudomonas strains (i.e., pf-5 and bbc6r8) from existing collecti ...	2014	25386184
diversity of pseudomonas genomes, including populus-associated isolates, as revealed by comparative genome analysis.	the pseudomonas genus contains a metabolically versatile group of organisms that are known to occupy numerous ecological niches, including the rhizosphere and endosphere of many plants. their diversity influences the phylogenetic diversity and heterogeneity of these communities. on the basis of average amino acid identity, comparative genome analysis of >1,000 pseudomonas genomes, including 21 pseudomonas strains isolated from the roots of native populus deltoides (eastern cottonwood) trees resu ...	2015	26519390
metabolic functions of pseudomonas fluorescens strains from populus deltoides depend on rhizosphere or endosphere isolation compartment.	the bacterial microbiota of plants is diverse, with 1000s of operational taxonomic units (otus) associated with any individual plant. in this work, we used phenotypic analysis, comparative genomics, and metabolic models to investigate the differences between 19 sequenced pseudomonas fluorescens strains. these isolates represent a single otu and were collected from the rhizosphere and endosphere of populus deltoides. while no traits were exclusive to either endosphere or rhizosphere p. fluorescen ...	2015	26528266
photosynthetic response of soybean to microclimate in 26-year-old tree-based intercropping systems in southern ontario, canada.	in order to study the effect of light competition and microclimatic modifications on the net assimilation (na), growth and yield of soybean (glycine max l.) as an understory crop, three 26-year-old soybean-tree (acer saccharinum marsh., populus deltoides x nigra, juglans nigra l.) intercropping systems were examined. tree competition reduced photosynthetically active radiation (par) incident on soybeans and reduced net assimilation, growth and yield of soybean. soil moisture of 20 cm depth close ...	2015	26053375
carbon sequestration potential in stands under the grain for green program in southwest china.	the grain for green program (ggp) is the largest afforestation and reforestation project in china in the early part of this century. to assess carbon sequestration in stands under the ggp in southwest china, the carbon stocks and their annual changes in the ggp stands in the region were estimated based on the following information: (1) collected data on the annually planted area of each tree species under the ggp in southwest china from 1999 to 2010; (2) development of empirical growth curves an ...	2016	26959645
qtls for woolly poplar aphid (phloeomyzus passerinii l.) resistance detected in an inter-specific populus deltoides x p. nigra mapping population.	the genus populus represents one of the most economically important groups of forest trees. it is composed by approximately 30 species used for wood and non-wood products, phytoremediation and biomass. poplar is subjected to several biological and environmental threats although, compared to annual crops, we know far less about the genetic bases of biotic stress resistance. woolly poplar aphid (phloeomyzus passerinii) is considered a main pest of cultivated poplars in european and american countr ...	2016	27022954
an essential role of caffeoyl shikimate esterase in monolignol biosynthesis in medicago truncatula.	biochemical and genetic analyses have previously identified caffeoyl shikimate esterase (cse) as an enzyme in the monolignol biosynthesis pathway in arabidopsis thaliana, although the generality of this finding has been questioned. here we show the presence of cse genes and associated enzyme activity in barrel medic (medicago truncatula, dicot, leguminosae), poplar (populus deltoides, dicot, salicaceae), and switchgrass (panicum virgatum, monocot, poaceae). loss of function of cse in transposon ...	2016	27037613
a luxr homolog in a cottonwood tree endophyte that activates gene expression in response to a plant signal or specific peptides.	homologs of the luxr acyl-homoserine lactone (ahl) quorum-sensing signal receptor are prevalent in proteobacteria isolated from roots of the eastern cottonwood tree, populus deltoides many of these isolates possess an orphan luxr homolog, closely related to oryr from the rice pathogen xanthomonas oryzae oryr does not respond to ahl signals but, instead, responds to an unknown plant compound. we discovered an oryr homolog, pipr, in the cottonwood endophyte pseudomonas sp. strain gm79. the genes a ...	2016	27486195
two poplar-associated bacterial isolates induce additive favorable responses in a constructed plant-microbiome system.	the biological function of the plant-microbiome system is the result of contributions from the host plant and microbiome members. the populus root microbiome is a diverse community that has high abundance of β- and γ-proteobacteria, both classes which include multiple plant-growth promoting representatives. to understand the contribution of individual microbiome members in a community, we studied the function of a simplified community consisting of pseudomonas and burkholderia bacterial strains ...	2016	27200001
dibenzo-α-pyrones: a new class of larvicidal metabolites against aedes aegypti from the endophytic fungus hyalodendriella sp. ponipodef12.	in our search for new agrochemicals from endophytic fungi, the crude extract of the endophytic hyalodendriella sp. ponipodef12 associated with the hybrid 'neva' of populus deltoides marsh × p. nigra l. was found to possess larvicidal activity against aedes aegypti.	2016	27862895
a carotenoid-deficient mutant in pantoea sp. yr343, a bacteria isolated from the rhizosphere of populus deltoides, is defective in root colonization.	the complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. a better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically important plants. pantoea sp. yr343 is a motile, rod-shaped bacterium isolated from the roots of populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone ...	2016	27148182