Project description:Aim of the project: Genome wide gene expression profiles across the cambial zone are analyzed in 35um resolution from wild type hybrid aspen (Populus tremula x tremuloides) and two independent LMX5::AtIPT7 over expressor transgenic Populus tree lines.
Project description:Thermospermine-induced transcriptomic changes were explored in Populus tremula x P. tremuloides. Transgenic hybrid aspen plants expressing 35S::POPACAULIS5 were compared to wild-type hybrid aspen under the influence of PGRs and depleted from PGRs.
Project description:In this study we report on transgenic hybrid aspen (Populus tremula x P. tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after five years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula x tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 (Potri.019G116400) that was selected from a gene-mining program for novel regulators of wood formation. A proteomic analysis was performed to characterize the overall effect of the overexpression of PttVAP27-17 on plant metabolic pathways. 20 mg of xylem sample for the selected wild type (WT) and three transgenic lines (lines 1,2 and 3) was collected in the following manner from two-months-old, greenhouse grown trees: The frozen bottom-part of the stem (10-17 cm portion from the base of the stem) was peeled, and the surface of the secondary xylem consisting of living vessels and fibers (into the depth of approximately one mm from the surface) was scraped. The xylem scrapings were ground to fine powder in liquid nitrogen and stored at -80oC. The analyses included 3-5 biological replicates for each of the transgenic lines, and seven replicates for the wild type.
Project description:Aim of the project: Genome wide gene expression analysis for cytokinin (100nM 2ip, 20nM NaPi buffer) fast (1h) response genes from 3 months old Hybrid aspen(Populus tremula x tremuloides)apical part (30 cm from tip; diameter:4-5mm) of stem. Stems of two individuals (trees 15 and 16) was cut into 50-100um thick (free hand)cross sections randomly selected stem discs are set to two pools: cytokinin treatment and control treatment. Samples are collected noon time (11:00-11:30). Cytokinin treatment: stem discs (several hundred) are submerged with 100nM 2ip, 20nM NaPi buffer, with modest shaking for 60 min +/- 2 min (time to collect about 30mg stem discs (several dozens) for RNA sample. Control treatment: identical to cytokinin treatment, only without 100nM 2ip.
Project description:The expression of stress-related genes induced by feeding of chestnut moth larvae (Conistra vaccinii L.) was studied with Vitreoscilla hemoglobin-expressing (VHb) and non-transgenic hybrid aspen lines (Populus tremula x P. tremuloides). Besides the herbivore-injured leaves (L1), cDNA microarray analyses were conducted using uninjured leaves of hybrid aspen lines positioned above (A) and below (B) the herbivory exposed leaves.
Project description:The expression of stress-related genes induced by feeding of chestnut moth larvae (Conistra vaccinii L.) was studied with Vitreoscilla hemoglobin-expressing (VHb) and non-transgenic hybrid aspen lines (Populus tremula x P. tremuloides). Besides the herbivore-injured leaves (L1), cDNA microarray analyses were conducted using uninjured leaves of hybrid aspen lines positioned above (A) and below (B) the herbivory exposed leaves. Two-condition experiment, control vs. herbivory exposure. Two hybrid aspen lines: non-transgenic V617 and VHb expressing V617 /45. Of each plant, three leaf types were analysed: the injured/uninjured leaf (L1) and nonorthostichous leaf positioned above (A) and below (B). Biological replicates: 3. On each array, two samples representing L1, A or B leaf type of control and herbivory treatment of either V617 or V617/45 line. line V617: wt_A_rep1-3, wt_B_rep1-3, wt_L1_rep1-3 line V617/45: VHb_A_rep1-3, VHb_B_rep1-3, VHb_L1_rep1-3 leaf type A: wt_A_rep1-3, VHb_A_rep1-3 leaf type B: wt_B_rep1-3, VHb_B_rep1-4 leaf type L1: wt_L1_rep1-3, VHb_L1_rep1-5
Project description:Previous studies have shown that a considerable proportion of the Arabidopsis genome cycles under circadian and/or diurnal conditions (Edwards et al., 2006 PMID: 16473970, Blaesing et al., 2005 PMID 16299223). It is likely that the correct phasing of gene expression plays an important role in improving the growth of the model plant (Dodd et al., 2005 PMID: 16040710). A key question is whether similar regulation is occurring in other higher plant species. In this study we measure the diurnal expression pattern of genes in the T89 clone of the hybrid aspen (Populus tremula L. x P. tremuloides Michx.) using the Affymetrix Poplar array. Samples (leaf blades) were taken at 4h intervals over the course of 2 diurnal cycles (18h Light: 6h Dark). Time-points were labelled relative to dawn (time 0) on the first day of sampling. T89 was selected as it has routinely been used for genetic modification since 1992 (Nilsson et al.) and is the genetic background for a large number of transgenic trees created in order to investigate the function of aspen genes, providing potential for genetic manipulations during our further studies. We also measured the diurnal expression pattern of genes in trees with a compromised circadian clock. Trees with less expressed LATE ELONGATED HYPOCOTYL 1 (LHY1) and LHY2 by RNA interference (lhy) line that was created in T89 clone of the aspen hybrid (Populus tremula L. x P. tremuloides Michx.) using the Affymetrix Poplar array. Samples (leaf blades) were taken at 4h intervals over the course of 2 diurnal cycles (18h Light: 6h Dark) as described above. Thus, time-points are labelled relative to dawn (time 0) on the first day of sampling. The data obtained from using a RNAi line in central Clock components complements the study of wild type T89, since they were grown and sampled at the same time under the same conditions.
Project description:Metacaspases (MCs) are cysteine proteases that are implicated in programmed cell death of plants. AtMC9 (Arabidopsis thaliana Metacaspase9) is a member of the Arabidopsis MC family that controls the rapid autolysis of the xylem vessel elements, but its downstream targets in the xylem remain uncharacterized. PttMC13 and PttMC14 were identified as AtMC9 homologs of hybrid aspen (Populus tremula x tremuloides). A proteomic analysis was conducted in xylem tissues of transgenic hybrid aspen trees which carried either an overexpression or an RNAi construct for PttMC13 and PttMC14. The proteomic analysis revealed modulation of levels of both previously known targets of metacaspases, such as Tudor staphylococcal nuclease, heat shock proteins and 14-3-3 proteins as well as novel targets, such as homologs of the PUTATIVE ASPARTIC PROTEASE 3 (PASPA3) (PASPA) and the cysteine protease RD21 by PttMC13 and PttMC14. We identified here the pathways and processes that are modulated by PttMC13 and PttMC14 in xylem tissues. In particular, the results indicate involvement of PttMC13 and/or PttMC14 in controlling not only xylem cell autolysis but also cell death. This work provides a valuable reference dataset on xylem specific metacaspase functions for future functional and biochemical analyses.