Project description:Expression of defense response-related transcripts could be affected upon leaf wounding such as after excision of leaf disks. In this experiment, transcripts were isolated from whole leaves and 5-cm2 excised leaf disks samples from interaction assays between leaves of the 'Beaupré' poplar cultivar (Poplus trichocarpa x Poplus deltoides) and virulent (98AG31, compatible interaction) and avirulent (93ID6, incompatible interaction) urediniospores of Melampsora larici-populina, the fungus responsible for the foliar rust disease in poplar. For each type of interaction, three samples were collected in a time-course series (18, 21 and 24 hpi for strain 93ID6, and 18, 24 and 48 hpi for strain 98AG31). Both leaf disks and whole leaves were inoculated in strictly similar conditions, so differential transcript expression is likely attributable to the wounding effect in leaf disks. The aim of this study is to identify genes that are induced by wounding in leaf disks compared with whole leaves. For this purpose, cDNA templates were used for hybridization on poplar oligoarrays.
Project description:We conducted micro-array analysis to quantify the global transcriptome variations in leaves through the course of the year allowing for identification of changing developmental signals. We used RNA samples from pre-formed and mature leaves in the upper crown of a sexually mature Populus deltoides tree 2 hours after sunrise. Three independent samples of leaf/pre-formed leaf tissues were collected from the upper crown of a single sexually mature tree. RNA was extracted from tissues and hybridized on Affymetrix Genechip Poplar Genome Array. Tissues represented two batches (batch 1 from 2005 and batch 2 from 2006). Therefore, March samples were used to normalize the other month samples within the same batch.
Project description:Populus deltoides and Populus trichocarpa were exposed to either ambient air or an acute ozone exposure of 200 ppb for 9 hrs and ozone response was profiled for each genotype by hybridising control against ozone-exposed samples per genotype. Keywords: stress response, genotype comparrison, ozone exposure RNA was extracted from the fifth leaf below the first fully unfurled leaf for each plant. Control and ozone-exposed plants were then randomly paired for hybridisation.
Project description:A microarray analysis of whole-genome gene expression in leaves was carried out in a (Populus trichocarpa X Populus deltoides) X Populus deltoides pseudo-backcross pedigree. Genetic variation in gene expression was quantified for 55,793 predicted gene models based on a single probe per gene. Resultant data contributed to the analysis of the genetic architecture of gene expression in leaves of Populus.
Project description:TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides) cell suspensions can activate a cellular program leading to cell death. In contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. This habituation was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than 18 months. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition, with a reduction in cellulose and an increase in pectin levels. Remarkably, high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover, these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis, dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications. Experiment Overall Design: Each sample was taken from an individual flask of control cells or TA-habituated resistant cells grown without the toxin for 18 months (TA(-)hab cells) that had grown for 5 d after subculture. Six arrays were hybridized, representing 3 arrays per cell type.
Project description:Populus deltoides and Populus trichocarpa were exposed to either ambient air or an acute ozone exposure of 200 ppb for 9 hrs and ozone response was profiled for each genotype by hybridising control against ozone-exposed samples per genotype. Keywords: stress response, genotype comparrison, ozone exposure
Project description:The proteomics method based on tandem mass tag (TMT) labeling was used to analyze the changes of the proteome in the leaves of both red-leaved poplar, so as to identified the key proteins related to red leaf coloration.
Project description:The purpose of this study was to evaluate a set of 6-7 long oligonucleotide probes developed based on the sequence of the Populus trichocarpa genome, that are optimal for gene expression analysis of P. deltoides and a hybrid of P. deltoides and P. trichocarpa. To evaluate these probes, multiple tissues (differentiating xyle, leaf and whole-root) of a pure P. deltoides and a hybrid (P. deltoides X P. trichocarpa) were transcript profiled for identification of one or more probes that are not biased towards one or the other genotype.
Project description:A microarray analysis of whole-genome gene expression in leaves was carried out in a (Populus trichocarpa X Populus deltoides) X Populus deltoides pseudo-backcross pedigree. Genetic variation in gene expression was quantified for 55,793 predicted gene models based on a single probe per gene. Resultant data contributed to the analysis of the genetic architecture of gene expression in leaves of Populus. Data include one biological replicate of 183 individuals segregating from a pseudo-backcross pedigree of (Populus trichocarpa X Populus deltoides) X Populus deltoides analyzed for gene expression (GE) in roots using one probe per gene for 55793 independent gene models (probes E_POPLARSxxxxxPxxxxx) and single feature sequence polymorphism (SFP) using one probe per gene for 12084 independent gene models (probes G_POPLARSxxxxxPxxxxx). GE and SFP probes were selected from 6-7 probes per gene previously tested in a pilot study of the two parent trees of the cross (Populus deltoides X Populus trichocarpa)
Project description:The absolute configuration of salicortin, HCH-salicortin and tremulacin, isolated from leaves of Populus trichocarpa × deltoides Beaupré, was determined by comparing spectroscopic data of these compounds with those of idescarpin, isolated from leaves of Idesia polycarpa. All compounds were characterized by nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and circular dichroism spectroscopy. It was found that the hydroxy cyclohexenonoyl (HCH) moiety in all compounds is (S)-configured. In addition, it was shown that leaves of Idesia polycarpa contain high amounts of (-)-idescarpin (1.1%, based on dry weight).