Project description:affy_pop_2011_08 - poplar bent study - genes regulated by PtaZFP2 in absence of mechanical stress - genes regulated by PtaZFP2 after one bending.Species: Populus tremula x Populus alba-- The laboratory previously established a poplar transgenic line overexpressing PtaZFP2 under the control of an estradiol-inducible promoter. - the experiment, conducted on 3-month-old hydroponically-grown poplars, consists in the comparison of WT poplars treated with estradiol and the PtaZFP2-overexpressing line treated with estradiol. We also compared unbent and bent PtaZFP2-overexpressing poplars. The applied strain is quantitatively controlled (Coutand & Moulia, 2000, JExpBot; coutand et al., 2009, Plant Physiology) - 27 arrays - poplar; gene knock in (transgenic)
Project description:We used whole-genome microarrays to identify differentially expressed genes in leaves of GA-deficient (35S::PcGA2ox) and/or GA-insensitive (35S::rgl1) transgenics as compared to WT poplar (717-1B4 genotype). Our work suggests that the molecular machinery that reduces gibberellins (GAs) concentration and signaling is a major route for restraining growth under both immediate and imminent adverse conditions. We show that inhibition of growth as a result of water deprivation and short days (SDs) coincides with up-regulation of several DELLA and GA2ox encoding genes in poplar. Likewise, GA-deficient and GA-insensitive transgenics, with up-regulated GA2ox and DELLA domain proteins, elicited a hypersensitive growth inhibition in response to both drought and SDs. Because the GA-modified transgenic showed accelerated response to drought and SD, we hypothesized that the mechanisms associated with these responses are constitutively elevated even under control conditions (well-watered, long day photoperiod). Therefore, we used whole-genome poplar microarray to study transcriptome level changes in the leaves of transgenic compared to WT plants grown under control environment.
Project description:The perennial genetically modified Populus 741, exhibiting sustained overexpression of PtoCYCD3;3, consistently shows adaxial curvature and pronounced surface wrinkling. To investigate these morphological changes, TMT quantitative proteomics and phosphoproteomics were performed on leaves of transgenic and wild-type plants. Quantitative proteomics identified significant changes in protein abundance associated with photosynthesis, phytohormones, and cell proliferation. Notably, histone deacetylase 6 (HDA6), ANGUSTIFOLIA (AN), and cellulose synthase-like (CSL) proteins associated with leaf curling were significantly upregulated in transgenic poplar. Phosphoproteomics revealed enrichment of proteins such as HERK1, DGK, OST1, and BIG, which are involved in brassinosteroid (BR), abscisic acid (ABA), and other phytohormone signaling pathways. These analyses demonstrated the impact of exogenous gene PtoCYCD3;3 integration on photosynthetic pathways, hormone signaling, and cell proliferation, highlighting its role in modulating leaf morphogenesis in perennial Populus 741.
Project description:affy_pop_2011_08 - poplar bent study - genes regulated by PtaZFP2 in absence of mechanical stress - genes regulated by PtaZFP2 after one bending.Species: Populus tremula x Populus alba-- The laboratory previously established a poplar transgenic line overexpressing PtaZFP2 under the control of an estradiol-inducible promoter. - the experiment, conducted on 3-month-old hydroponically-grown poplars, consists in the comparison of WT poplars treated with estradiol and the PtaZFP2-overexpressing line treated with estradiol. We also compared unbent and bent PtaZFP2-overexpressing poplars. The applied strain is quantitatively controlled (Coutand & Moulia, 2000, JExpBot; coutand et al., 2009, Plant Physiology) - 27 arrays - poplar; gene knock in (transgenic) 27 samples are wt; for this experiment only the bending comparaison are studied.
Project description:affy_pop_2011_08 - poplar estradiol study - genes regulated by PtaZFP2 in absence of mechanical stress - genes regulated by PtaZFP2 after one bending.Species: Populus tremula x Populus alba-The laboratory previously established a poplar transgenic line overexpressing PtaZFP2 under the control of an estradiol-inducible promoter. - the experiment, conducted on 3-month-old hydroponically-grown poplars, consists in the comparison of WT poplars treated with estradiol and the PtaZFP2-overexpressing line treated with estradiol. We also compared unbent and bent PtaZFP2-overexpressing poplars. The applied strain is quantitatively controlled (Coutand & Moulia, 2000, JExpBot; coutand et al., 2009, Plant Physiology)
Project description:Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement.
Project description:Whole-genome resequencing of eight transcription factor mutants and one wild-type, in order to verify the T-DNA insertion site and its uniqueness.
Project description:<p>Rust fungi are plant pathogens that cause epidemics which threatens the production of many important plant species, such as wheat, soy, coffee and poplar. Melampsora larici-populina (Mlp) causes the poplar rust and encodes at least 1184 candidate effectors (CEs), however their functions are poorly known. In this study, we analysed the transcriptome and metabolome of Arabidopsis constitutively expressing CEs of Mlp to discover processes targeted by these fungal proteins. For this purpose, we sequenced the transcriptome and used mass spectrometry to analyse the metabolome of Arabidopsis plants expressing one of 14 selected CEs and of a control line. We found 2299 deregulated genes in at least one of the 14 transgenic lines. Among the down-regulated genes, the KEGG pathways “MAPK signaling pathway” and “Plant-pathogen interaction” were over-represented in six and five of the 14 transgenic lines, respectively. Moreover, the genes down-regulated across the fourteen transgenic lines are related to hormone response and defense. </p><p>Regarding the metabolome, there were 680 metabolites deregulated across the 14 transgenic lines, with highly unsaturated and phenolic compounds and peptides enriched among down-regulated and up-regulated metabolites, respectively, in almost all transgenic lines. Interestingly, we found that some transgenic lines expressing CEs with no similarity in amino acid sequence had similar patterns of gene and metabolite deregulation, while plants expressing CEs from the same family deregulated different genes and metabolites. Taken together, our results indicate that the sequence of effectors may not be a good predictor of its impact in the plant.</p>
Project description:Soil-borne microbes can establish compatible relationships with host plants, providing a large variety of nutritive and protective compounds in exchange for photosynthesized sugars. However, the molecular mechanisms mediating the establishment of these beneficial relationships remain unclear. Our previous genetic mapping and whole-genome resequencing studies identified a gene deletion event of a Populus trichocarpa lectin receptor-like kinase gene PtLecRLK1 in Populus deltoides that was associated with poor root colonization by the ectomycorrhizal fungus Laccaria bicolor. By introducing PtLecRLK1 into a perennial grass known to be a non-host of L. bicolor, switchgrass (Panicum virgatum L.), we found that L. bicolor colonizes ZmUbipro-PtLecRLK1 transgenic switchgrass roots, which illustrates that the introduction of PtLecRLK1 has the potential to convert a non-host to a host of L. bicolor. Furthermore, transcriptomic and proteomic analyses on inoculated transgenic switchgrass roots revealed genes/proteins overrepresented in the compatible interaction and underrepresented in the pathogenic defense pathway, consistent with the view that pathogenic defense response is downregulated during compatible interaction. Metabolomic profiling revealed that root colonization in the transgenic switchgrass was associated with an increase in N-containing metabolites and a decrease in organic acids, sugars, and aromatic hydroxycinnamate conjugates, which are often seen in the early steps of establishing compatible interactions. These studies illustrate that PtLecRLK1 is able to render a plant susceptible to colonization by the ectomycorrhizal fungus L. bicolor and shed light on engineering mycorrhizal symbiosis into a non-host to enhance plant productivity and fitness on marginal lands.