Project description:Poplars are known to be highly tolerant species to boron toxicity and accumulation. However, genes and molecular networks responsible in boron toxicity tolerance have not been investigated yet. Therefore, we performed a pot experiment with 20 black poplar clones collected from the vicinity of boron mines and polluted areas to investigate its potential role in phytoremediation and to select the most boron toxicity tolerant genotype. Trees were treated with irrigation water containing seven elevated boron concentrations from 0 to 160 ppm. Then a microarray based comparative transcriptome profiling was conducted to identify boron toxicity regulated genes responsible in defence responses of black poplar. The results of the study indicated that black poplar is quite suitable for phytoremediation of boron pollution. It could resist 15 ppm soil B content and < 1600 mg/kg boron accumulation in leaves which are highly toxic concentrations for almost all agricultural plants. Transcriptomics results of study revealed totally 1625 and 1419 altered probe sets under boron toxicity in leaf and root tissues, respectively. The highest induction were recorded for the probes sets annotated to tyrosine aminotransferase, ATP binding cassette transporters, glutathione S transferases and metallochaperone proteins. Strong up regulation of these genes attributed to internal excretion of boron into the cell vacuole and existence of detoxification processes in black poplar. Many candidate genes functional in signalling, gene regulation, antioxidation, boron uptake, transport and detoxification processes were also identified in the current study. This is the first transcriptomic study identifying boron toxicity regulated poplar genes and their potential role in boron toxicity tolerance.
Project description:Poplars are known to be highly tolerant species to boron toxicity and accumulation. However, genes and molecular networks responsible in boron toxicity tolerance have not been investigated yet. Therefore, we performed a pot experiment with 20 black poplar clones collected from the vicinity of boron mines and polluted areas to investigate its potential role in phytoremediation and to select the most boron toxicity tolerant genotype. Trees were treated with irrigation water containing seven elevated boron concentrations from 0 to 160 ppm. Then a microarray based comparative transcriptome profiling was conducted to identify boron toxicity regulated genes responsible in defence responses of black poplar. The results of the study indicated that black poplar is quite suitable for phytoremediation of boron pollution. It could resist 15 ppm soil B content and < 1600 mg/kg boron accumulation in leaves which are highly toxic concentrations for almost all agricultural plants. Transcriptomics results of study revealed totally 1625 and 1419 altered probe sets under boron toxicity in leaf and root tissues, respectively. The highest induction were recorded for the probes sets annotated to tyrosine aminotransferase, ATP binding cassette transporters, glutathione S transferases and metallochaperone proteins. Strong up regulation of these genes attributed to internal excretion of boron into the cell vacuole and existence of detoxification processes in black poplar. Many candidate genes functional in signalling, gene regulation, antioxidation, boron uptake, transport and detoxification processes were also identified in the current study. This is the first transcriptomic study identifying boron toxicity regulated poplar genes and their potential role in boron toxicity tolerance. Total RNA used in microarray experiment was isolated from the leaves and roots of black poplar clone; N.92.237 which accumulated the highest amount of boron its tissues. Total RNA used in the microarray experiment was isolated from leaves and roots of three black poplar saplings grown in ~ 2 ppm (control) and ~ 15 ppm (toxic) soil B contents. RNA isolation was made according to Lithium chloride precipitation method described in Chang et al. (1993). These three isolated RNAs (biological replicates) for each tissue loaded onto three Affymetrix poplar Gene Chips (technical replicates). Totally, 12 GeneChips (2 tissues Ã? 2 different B treatment Ã? 3 biological replicates) were used for transcriptional analysis.
Project description:Drought-treated and corresponding control root tissue of poplar was subjected to array analyses Two-condition experiment, control (K) vs. Drought-stressed (S) leaves. Biological replicates: 3 control (1-3), drought-exposed (1-3), independently grown and harvested. One swap replicate per array.
Project description:We study the effect of nitrogen limitation on the growth and development of poplar roots. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes driven by low nitrogen in the growth media. We report the effect of nitrogen limitation on the growth and development of poplar roots. Low nitrogen concentration led to increased root elongation followed by lateral root proliferation and finally increased root biomass. These morphological responses correlated with high and specific activation of genes encoding regulators of cell cycle and enzymes involved in cell wall biogenesis, growth and remodeling. Comparative analysis of poplar and Arabidopsis root transcriptomes under nitrogen deficiency indicated many similarities and diversification in the response in the two species. A reconstruction of genetic regulatory network (GRN) analysis revealed a sub-network centered on a PtaNAC1-like transcription factor. Consistent with the GRN predictions, root-specific upregulation of PtaNAC1 in transgenic poplar plants increased root biomass and led to significant changes in the expression of the connected genes specifically under low nitrogen. PtaNAC1 and its regulatory miR164 showed inverse expression profiles during response to LN, suggesting of a micro RNA mediated attenuation of PtaNAC1 transcript abundance in response to nitrogen deprivation.
Project description:affy_popsec_nancy_pophydro_roots_poplar - This project aims to identify genes of interest for control of root growth in response to water deficit in a tree species: poplar. We look for genes and gene expression networks related to drought stress. We intend to analyse the transcriptome in root apices of cuttings grown in hydroponics and osmotically stressed with PEG. Root apex is the location of root elongation and these analyses intend to identify genes involved in the control of cell expansion and thus of root elongation. Indeed, root growth maintenance in response to water shortage contributes to plant tolerance to water deficit.-Poplar cuttings (cv Soligo) were grown in hydroponics. A moderate water deficit was applied by adding PEG to the nutrient solution (200g/l). After 3 days, the apex (1 cm-long) of the roots of each cutting were collected. For control and stressed treatments, RNAs were extracted from two pools of 5 to 9 roots (issued from 2 to 5 cuttings). A pool is considered as one biological replicate and corresponds to one Affymetrix slide. Keywords: treated vs untreated comparison 4 arrays - poplar
Project description:affy_popsec_nancy_pophydro_roots_poplar - This project aims to identify genes of interest for control of root growth in response to water deficit in a tree species: poplar. We look for genes and gene expression networks related to drought stress. We intend to analyse the transcriptome in root apices of cuttings grown in hydroponics and osmotically stressed with PEG. Root apex is the location of root elongation and these analyses intend to identify genes involved in the control of cell expansion and thus of root elongation. Indeed, root growth maintenance in response to water shortage contributes to plant tolerance to water deficit.-Poplar cuttings (cv Soligo) were grown in hydroponics. A moderate water deficit was applied by adding PEG to the nutrient solution (200g/l). After 3 days, the apex (1 cm-long) of the roots of each cutting were collected. For control and stressed treatments, RNAs were extracted from two pools of 5 to 9 roots (issued from 2 to 5 cuttings). A pool is considered as one biological replicate and corresponds to one Affymetrix slide. Keywords: treated vs untreated comparison
Project description:The molecular responses of Grey poplar (Populus x canescens) following root hypoxia were studied in roots and leaves using transcript profiling. Grey poplar is a flooding tolerant tree species and analysis of the molecular response to hypoxia may indicate possible adaptation mechanisms to this stress.