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:Poplar 84K (Populus alba x P. tremula var. glandulosa) is a fast-growing poplar hybrid. Originated in South Korea, this hybrid has been extensively cultivated in northern China. Due to the economic and ecological importance of this hybrid and high transformability, we now report the de novo sequencing and assembly of a male individual of poplar 84K using PacBio and Hi-C technologies. The final reference nuclear genome (747.5?Mb) has a contig N50 size of 1.99?Mb and a scaffold N50 size of 19.6?Mb. Complete chloroplast and mitochondrial genomes were also assembled from the sequencing data. Based on similarities to the genomes of P. alba var. pyramidalis and P. tremula, we were able to identify two subgenomes, representing 356?Mb from P. alba (subgenome A) and 354?Mb from P. tremula var. glandulosa (subgenome G). The phased assembly allowed us to detect the transcriptional bias between the two subgenomes, and we found that the subgenome from P. tremula displayed dominant expression in both 84K and another widely used hybrid, P. tremula x P. alba. This high-quality poplar 84K genome will be a valuable resource for poplar breeding and for molecular biology studies.
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:Plants have evolved defense mechanisms to overcome unfavorable climatic conditions. The growth and development of plants are regulated in response to environmental stress. In this study, we investigated the molecular and physiological characteristics of a novel gene PagSAP11 in hybrid poplar (Populus alba × Populus tremula var. glandulosa) under drought stress. PagSAP11, a stress-associated protein (SAP) family gene, encodes a putative protein containing an A20 and AN1 zinc-finger domain at its N- and C-termini, respectively. Knockdown of PagSAP11 transgenic poplars (SAP11-Ri) enhanced their tolerance to drought stress compared with wild type plants. Moreover, the RNAi lines showed increased branching of lateral shoots that led to a gain in fresh weight, even when grown in the living modified organism (LMO) field. In SAP11-Ri transgenic plants, the expression levels of genes involved in axillary bud outgrowth and cell proliferation such as DML10, CYP707A and RAX were increased while the DRM gene which involved in bud dormancy was down-regulated. Taken together, these results indicate that PagSAP11 represents a promising candidate gene for engineering trees with improved stress tolerance and growth during unfavorable conditions.
Project description:Poplar 84 K (Populus alba x P. tremula var. glandulosa) is a good resource for genetic engineering due to its rapid growth and wide adaptability, and it is also an excellent ornamental tree species. In this study, we used 84 K plantlets grown in the nitrogen-limited medium as experimental materials to explore the molecular mechanism in 84 K leaves under nitrogen deficiency. A total of 5,868 differentially expressed genes (DEGs) were identified using the transcriptional information from RNA-seq data. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment results revealed that the DEGs were mainly involved in energy metabolism and anthocyanin biosynthesis. We then identified differentially expressed transcription factors (TFs) and constructed TF centered gene co-expression networks for chlorophyll and anthocyanin biosynthesis pathway genes. Twenty potential regulators were finally identified. We speculated the transcription factors that control the pigmentation in leaves with the MYB-bHLH-WD40 (MBW) pigment regulatory model. Such identification will clarify the genetic basis of the secondary metabolism in 84 K, and being a source of candidate genes for future plant genetic engineering. Our work broadens the researchers' understanding of the regulation of anthocyanin synthesis in trees and provides new perspectives for ornamental 84 K poplar breeding.Supplementary informationThe online version contains supplementary material available at 10.1007/s12298-021-01012-3.
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 performed that comprehensive identification of genes responsible for stress tolerance by analyzing the whole-genome expression profiles of poplar (Populus alba × P. glandulosa) leaves exposed to drought and salt stresses. Examination at the molecular level how this tree species responds to drought and salt stresses by regulating the expression of genes involved in signal transduction, transcriptional regulation, and stress responses.
Project description:Microarray technology was used to assess transcriptome changes in poplar (Populus alba L.) under a realistic simulation of increased UV-B radiation. Plants were UV-Bbe (UV-B biologically effective radiation) supplemented with a dose of 6 kJ/m2/day for 12 hours per day and allowed to recover during the night. Poplar plants were UV-B treated using a refined controlled environment able to guarantee a realistic simulation of natural conditions, especially for light parameters such as presence of background UV-B radiation for control plants and balanced PAR/UV-A/UV-B ratio. A time course experiment was planned to look both at the rapid and delayed response of poplar to UVB; two time points after 3 h (T3h) and 30 h (6th hour of the third day of treatment, T30h) were considered. 4 independent biological replicates were analysed for each time point. Competitive hybridisations were carried out using the PICME 28K microarray. Keywords: Time course experiment, stress response