Project description:To obtain genes expression in different parts of 84k poplar stems, transcriptome sequencing was performed using Illumina Novaseq 6000 second-generation sequencing platform from Shanghai BIOZERON Co. Ltd (www.biozeron.com). Selecte three stem segments of plants REPEAT 1, 2 and 3 with good and similar growth to use: 2nd-3rd internodes (poplar stem top: PST1, PST2, PST3); 9th-10th internodes (poplar stem middle: PSM1, PSM2, PSM3); 14th-15th internodes (poplar stem bottom: PSB1, PSB2, PSB3). [Or the three repeating organisms are also called poplar A, B, C. From top to bottom, the three parts of the stem are also called stem 1, 2, 3.]
Project description:Here we applied a novel approach to isolate nuclei from complex plant tissues (https://doi.org/10.1371/journal.pone.0251149), to dissect the transcriptome profiling of the hybrid poplar (Populus tremula × alba) vegetative shoot apex at single-cell resolution.
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:Plants transition through juvenile and adult phases of vegetative development in a process known as vegetative phase change (VPC). In poplars (genus Populus) the differences between these stages are subtle, making it difficult to determine when this transition occurs. Previous studies of VPC in poplars have relied on plants propagated in vitro, leaving the natural progression of this process unknown. We examined developmental morphology of seed-grown and in vitro derived Populus tremula × alba (clone 717-1B4), and compared the phenotype of these to transgenics with manipulated miR156 expression, the master regulator of VPC. In seed-grown plants, most traits changed from node-to-node during the first 3 months of development but remained constant after node 25. Many traits remained unchanged in clones over-expressing miR156, or were enhanced when miR156 was lowered, demonstrating their natural progression is regulated by the miR156/SPL pathway. The characteristic leaf fluttering of Populus is one of these miR156-regulated traits. Vegetative development in plants grown from culture mirrored that of seed-grown plants, allowing direct comparison between plants often used in research and those found in nature. These results provide a foundation for further research on the role of VPC in the ecology and evolution of this economically important genus.
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. Poplar roots from low nitrogen treated and untreated from in vitro condition was selected for RNA extraction and hybridization on Affymetrix microarrays. Roots were sampled at 6, 12, 24, 48, 96 and 504h after transfer to control and low nitrogen media and RNA was extacted.
Project description:Illumina technology was used to generate mRNA profiles of Populus tremula x alba 717-1B4 control roots and Laccaria bicolor S238N ectomycorrhiza. Total RNA was extracted, TruSeq mRNA Stranded libraries were constructed and and sequenced (2 x 150 bp Illumina HiSeq3000) at the Genotoul sequencing facilities (Toulouse, France). Raw reads were trimmed for low quality (quality score 0.05), Illumina adapters and sequences shorter than 15 nucleotides and aligned to the Populus trichocarpa v4.1 primary transcripts available at Phytozome (https://phytozome-next.jgi.doe.gov/info/Ptrichocarpa_v4_1l) using CLC Genomics Workbench v24.
Project description:We have employed snRNA-seq using Singleron technology to dissect the molecular mechanisms controlling secondary xylem plasticity, which allows poplar trees to cope with severe drought. We generated four snRNA-seq libraries using mature stem sections, two per treatment. In this study, we present new molecular drivers of wood plasticity under drought, which allow trees to generate secondary xylem with more and narrower vessels. This trait confers a better adaptation under this abiotic stress. We also performed bulk RNA-seq under the same conditions to evaluate the accuracy of snRNA-seq in our analyses.