The Experts below are selected from a list of 495 Experts worldwide ranked by ideXlab platform

Deqiang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • genetic architecture underlying the metabolites of chlorogenic acid biosynthesis in Populus tomentosa
    International Journal of Molecular Sciences, 2021
    Co-Authors: Liangchen Yao, Mingyang Quan, Liang Xiao, Fangyuan Song, Yuanyuan Fang, Deqiang Zhang
    Abstract:

    Chlorogenic acid (CGA) plays a crucial role in defense response, immune regulation, and the response to abiotic stress in plants. However, the genetic regulatory network of CGA biosynthesis pathways in perennial plants remains unclear. Here, we investigated the genetic architecture for CGA biosynthesis using a metabolite-based genome-wide association study (mGWAS) and expression quantitative trait nucleotide (eQTN) mapping in a population of 300 accessions of Populus tomentosa. In total, we investigated 204 SNPs which were significantly associated with 11 metabolic traits, corresponding to 206 genes, and were mainly involved in metabolism and cell growth processes of P. tomentosa. We identified 874 eQTNs representing 1066 genes, in which the expression and interaction of causal genes affected phenotypic variation. Of these, 102 genes showed significant signatures of selection in three geographical populations, which provided insights into the adaptation of CGA biosynthesis to the local environment. Finally, we constructed a genetic network of six causal genes that coordinately regulate CGA biosynthesis, revealing the multiple regulatory patterns affecting CGA accumulation in P. tomentosa. Our study provides a multiomics strategy for understanding the genetic basis underlying the natural variation in the CGA biosynthetic metabolites of Populus, which will enhance the genetic development of abiotic-resistance varieties in forest trees.

  • transcriptome analysis and association mapping revealed the genetic regulatory network response to cadmium stress in Populus tomentosa
    Journal of Experimental Botany, 2020
    Co-Authors: Mingyang Quan, Yuepeng Song, Deqiang Zhang, Xin Liu, Liang Xiao, Panfei Chen, Fangyuan Song
    Abstract:

    Long non-coding RNAs (lncRNAs) play essential roles in plant abiotic stress responses, however, the lncRNA-mediated genetic networks response to cadmium (Cd) treatment remain elusive in trees, the promising phytoremediation candidates for Cd contamination. Here, we identified 172 Cd-responsive lncRNAs and 295 differentially expressed target genes in the leaves of Populus tomentosa under Cd treatment. Functional annotation revealed that these lncRNAs involved in various processes, including photosynthesis, hormone regulation, and phenylalanine metabolism. Association studies identified 78 significant associations, representing 14 Cd-responsive lncRNAs and 28 target genes for photosynthetic and leaf physiological traits. Epistasis uncovered 83 pairwise interactions among these traits, unveiling Cd-responsive lncRNA-mediated genetic networks for photosynthesis and leaf physiology in P. tomentosa. We then focused on the roles of two Cd-responsive lncRNA-gene pairs, MSTRG.22608.1-PtoMYB73 and MSTRG.5634.1-PtoMYB27, in Cd tolerance of Populus, and detected insertions/deletions within lncRNAs as polymorphisms driving target gene expression. LncRNAs genotype analysis and heterologous overexpressing PtoMYB73 and PtoMYB27 in Arabidopsis indicated their positive effects on enhancing Cd tolerance, photosynthetic rate, and leaf growth, and the potential interaction mechanisms of PtoMYB73 with abiotic stresses. Our study provides the genetic basis for Populus response to Cd treatment, facilitating genetic improvement of enhancing Cd tolerance in trees.

  • The Interactions between the Long Non-coding RNA NERDL and Its Target Gene Affect Wood Formation in Populus tomentosa
    Frontiers Media S.A., 2017
    Co-Authors: Mingyang Quan, Wan Shi, Deqiang Zhang
    Abstract:

    Long non-coding RNAs (lncRNAs) are important regulatory factors for plant growth and development, but little is known about the allelic interactions of lncRNAs with mRNA in perennial plants. Here, we analyzed the interaction of the NERD (Needed for RDR2-independent DNA methylation) Populus tomentosa gene PtoNERD with its putative regulator, the lncRNA NERDL (NERD-related lncRNA), which partially overlaps with the promoter region of this gene. Expression analysis in eight tissues showed a positive correlation between NERDL and PtoNERD (r = 0.62), suggesting that the interaction of NERDL with its putative target might be involved in wood formation. We conducted association mapping in a natural population of P. tomentosa (435 unrelated individuals) to evaluate genetic variation and the interaction of the lncRNA NERDL with PtoNERD. Using additive and dominant models, we identified 30 SNPs (P < 0.01) associated with five tree growth and wood property traits. Each SNP explained 3.90–8.57% of phenotypic variance, suggesting that NERDL and its putative target play a common role in wood formation. Epistasis analysis uncovered nine SNP-SNP association pairs between NERDL and PtoNERD, with an information gain of -7.55 to 2.16%, reflecting the strong interactions between NERDL and its putative target. This analysis provides a powerful method for deciphering the genetic interactions of lncRNAs with mRNA and dissecting the complex genetic network of quantitative traits in trees

  • Full Paper Identification of additive, dominant, and epistatic
    2016
    Co-Authors: Par K Ingvarsson, Deqiang Zhang
    Abstract:

    variation conferred by key genes in cellulose biosynthesis pathway in Populus tomentosa

  • Zhang D: Development and Application of Microsatellites in candidate genes related to wood properties in the Chinese white poplar (Populus tomentosa Carr
    2016
    Co-Authors: Chenrui Gong, Wei Pan, Deqiang Zhang
    Abstract:

    Gene-derived simple sequence repeats (genic SSRs), also known as functional markers, are often pre-ferred over random genomic markers because they represent variation in gene coding and/or regulatory regions. We characterized 544 genic SSR loci derived from 138 candidate genes involved in wood forma-tion, distributed throughout the genome of Populus tomentosa, a key ecological and cultivated wood pro-duction species. Of these SSRs, three-quarters were located in the promoter or intron regions, and dinucleotide (59.7%) and trinucleotide repeat motifs (26.5%) predominated. By screening 15 wild P. tomentosa ecotypes, we identified 188 polymorphic genic SSRs with 861 alleles, 2–7 alleles for each marker. Transferability analysis of 30 random genic SSRs, testing whether these SSRs work in 26 geno-types of five genus Populus sections (outgroup, Salix matsudana), showed that 72 % of the SSRs could be amplified in Turanga and 100 % could be amplified in Leuce. Based on genotyping of these 26 genotypes, a neighbour-joining analysis showed the expected six phylogenetic groupings. In silico analysis of SSR vari-ation in 220 sequences that are homologous between P. tomentosa and Populus trichocarpa suggested that genic SSR variations between relatives were predominantly affected by repeat motif variations or flanking sequence mutations. Inheritance tests and single-marker associations demonstrated the power of geni

Yadi Liu - One of the best experts on this subject based on the ideXlab platform.

  • chloroplast thylakoid ascorbate peroxidase ptotapx plays a key role in chloroplast development by decreasing hydrogen peroxide in Populus tomentosa
    Journal of Experimental Botany, 2021
    Co-Authors: Yadi Liu, Xiaorui Guo, Xiatong Liu, Chong Zhang, Keith Ka Ki Mai, Byungho Kang, Inhwan Hwang
    Abstract:

    Chloroplast development is a complex process that is critical to the growth and development of plants. However, the detailed mechanism of chloroplast development in woody plants remains unclear. In this study, we showed that chloroplasts with elaborate thylakoids could develop from proplastids in the cells of calli derived from leaf tissues of Populus tomentosa upon exposure to light. Chloroplast development was confirmed at the molecular and cellular levels. Transcriptome analysis revealed that genes related to photoreceptors and photosynthesis were significantly up-regulated during chloroplast development in a time-dependent manner. In light-induced chloroplast development, a key process was the removal of hydrogen peroxide, in which thylakoid-localized PtotAPX played a major role; light-induced chloroplast development was enhanced in PtotAPX-overexpressing transgenic P. tomentosa callus with lower levels of hydrogen peroxide, but was suppressed in PtotAPX antisense transgenic callus with higher levels of hydrogen peroxide. Moreover, the suppression of light-induced chloroplast development in PtotAPX antisense transgenic callus was relieved by the exogenous reactive oxygen species scavenging agent N,N'-dimethylthiourea (DMTU). Based on these results, we propose that PtotAPX-mediated removal of reactive oxygen species plays a key role in chloroplast development from proplastids upon exposure to light in P. tomentosa.

  • improving sample preparation to investigate lignin intensity of xylem at the cellular level by confocal raman microspectroscopy of Populus tomentosa
    Journal of Forestry Research, 2020
    Co-Authors: Bing Wang, Mei Luo, Yadi Liu, Xiaorui Guo, Xiatong Liu, Chong Zhang, Zhijing Zhao, Di Liu
    Abstract:

    Confocal Raman microspectroscopy (CRM) is an important tool for analyzing the compositional distribution of cell walls in situ. In this study, we improved the sample preparation method using paraffin-embedded sections combined with hexane dewaxing to obtain high resolution Raman images. We determined that the cell wall components of fiber cells were different from those of ray cells and vessel cells in the xylem of Populus tomentosa. Acetyl bromide and CRM methods produced similar trends when the difference in lignin intensity in the xylem region was compared between transgenic PtrLac4 and wild-type P. tomentosa. However, CRM proved more useful to analyze the lignin distribution in each cell type and distinguished the detailed difference in lignin intensity at the cellular level. Thus, CRM proved to be a useful in situ method to rapidly analyze the spatial variation of lignin content in the xylem of woody plants.

  • ptomtapx a mitochondrial ascorbate peroxidase plays an important role in maintaining the redox balance of Populus tomentosa carr
    Scientific Reports, 2019
    Co-Authors: Bin Yin, Yadi Liu, Chong Zhang, Zhijing Zhao, Jiaxue Zhang, Xiang Pan, Di Liu
    Abstract:

    Plant mitochondria are important energy-producing structure and ROS are generated as byproducts. APX is one enzyme of the AsA-GSH cycle to reduces H2O2 to water. We identified both PtomtAPX and PtosAPX are located in mitochondria of Populus tomentosa Carr. PtomtAPX is specifically targeted to mitochondria, while PtosAPX is dual targeted to both chloroplast and mitochondria. The expression of PtomtAPX in mitochondria was 60-fold that of PtosAPX by ELISA and qPCR analysis. Under high light stress, the expression levels of PtosAPX increased, while that of PtomtAPX only slightly changed. Compared to the WT, the antisense transgenic PtomtAPX cell lines showed slowed growth, smaller cells impaired mitochondria in MS medium under normal growth. RNA-seq results showed 3121 genes significantly altered expression in the antisense cells, and most of them are important for mitochondrial function, particularly in oxidative phosphorylation. Our findings demonstrates a mitochondrial location for one APX isoform, and provide valuable insight into the mechanism which ROS balance is modulated by AsA-GSH cycle in mitochondria.

Kai Gao - One of the best experts on this subject based on the ideXlab platform.

  • altered sucrose metabolism and plant growth in transgenic Populus tomentosa with altered sucrose synthase ptss3
    Transgenic Research, 2020
    Co-Authors: Kai Gao, Bingqi Lei, Jing Zhou, Ting Guo
    Abstract:

    Improvement of wood quality is an important focus of forest genetics and breeding research. Sucrose synthase (SS) catalyzes the reaction of sucrose and uridine diphosphate into uridine diphosphate glucose and fructose. It is a key enzyme involved in cell wall formation during secondary growth by providing the UDP-Glucose substrate for cellulose biosynthesis. In this study, we isolated the single-copy gene PtSS3 from the SS gene family of Populus tomentosa and analyzed its structure. To identify its function in secondary growth, we generated 19 transgenic lines of P. tomentosa using PtSS3 overexpression (OE) and artificial microRNA (amiRNA) constructs. We also performed comprehensive analyses of the transgenic P. tomentosa plants, including phenotypic analyses, quantitative real-time PCR, enzyme activity assays and sugar metabolism. We found significantly higher PtSS3 enzyme activity, fructose, and glucose levels and significantly lower sucrose levels in the stems and leaves of OE-PtSS3 plants. The opposite trend was observed in the amiRNA-PtSS3 lines. Gene expression analyses showed that PtSS3 transcript levels in stems and leaves were up-regulated in the OE-PtSS3 lines and down-regulated in the amiRNA-PtSS3 lines, and the OE-PtSS3 plants grew taller than the wild-type and amiRNA-PtSS3 plants. These findings indicate that PtSS3 plays an important role in sucrose metabolism and growth of trees.

  • genome wide analysis of the poplar nf y gene family and its expression in floral bud development of Populus tomentosa
    Trees-structure and Function, 2020
    Co-Authors: Kai Gao, Wasif Ullah Khan, Xiong Yang, Xiaoyu Yang, Tianyun Zhao, Zhong Chen
    Abstract:

    Key message The NF-Y gene family was identified and characterized in Populus trichocarpa by genome-wide analysis. Expression of PtoNF-Y was analyzed during floral bud development in Populus tomentosa.

  • a global view of transcriptome dynamics during male floral bud development in Populus tomentosa
    Scientific Reports, 2018
    Co-Authors: Kai Gao, Xiaoyu Yang, Tianyun Zhao, Zhong Chen, Pian Rao, Xiong Yang
    Abstract:

    To obtain a comprehensive overview of the dynamic transcriptome during male floral bud development in Populus tomentosa, high-throughput RNA-seq was conducted during eight flowering-related stages. Among the 109,212 de novo assembled unigenes, 6,959 were differentially expressed during the eight stages. The overrepresented classed of genes identified by Gene Ontology (GO) enrichment included ‘response to environmental stimuli’ and ‘plant-type spore development’. One-third of the differentially expressed genes were transcription factors (TFs). Several genes and gene families were analyzed in depth, including MADS-box TFs, Squamosa promoter binding protein-like family, receptor-like kinases, FLOWERING LOCUS T/TERMINAL-FLOWER-LIKE 1 family, key genes involved in anther and tapetum development, as well as LEAFY, WUSCHEL and CONSTANS. The results provided new insights into the roles of these and other well known gene families during the annual flowering cycle. To explore the mechanisms regulating poplar flowering, a weighted gene co-expression network was constructed using 98 floral-related genes involved in flower meristem identity and flower development. Many modules of co-expressed genes and hub genes were identified, such as APETALA1 and HUA1. This work provides many new insights on the annual flowering cycle in a perennial plant, and a major new resource for plant biology and biotechnology.

  • Variation in the Growth Traits and Wood Properties of Hybrid White Poplar Clones
    MDPI AG, 2015
    Co-Authors: Youming Dong, Zhong Chen, Bingqi Lei, Weihua Liao, Kai Gao
    Abstract:

    The physical and chemical properties of poplar clones largely determine their suitability for different applications. The main objective of this study was to investigate clonal variation in four hybrid poplar clones grown at three sites in North China and identify the superior clone. Study materials were collected from four clones of hybrid white poplar: Populus tomentosa “LM50”, used as the control; two clones (Yiyang-1 and Yiyang-2), new hybrids of (P. tomentosa × P. bolleana) × P. tomentosa “Truncata”; and Yiyang-3, a new hybrid of (P. tomentosa × P. bolleana) × P. tomentosa “LM50”. In total, 192 individuals from four hybrid clones were randomly chosen for sampling. The growth traits of four 7-year-old clones were examined at three sites. We also measured the wood properties of four 6-year-old clones at the Fengfeng nursery. Variation in the growth traits and the ranking of stem volumes differed among sites. Fiber traits and wood chemical components showed significant interclonal variation. With regard to the comprehensive growth rate, cellulose content, holocellulose content, and fiber traits, Yiyang-1 exhibited the best performance among the four hybrid poplar clones, indicating its utility as a raw material for pulp and papermaking

Mingyang Quan - One of the best experts on this subject based on the ideXlab platform.

  • genetic architecture underlying the metabolites of chlorogenic acid biosynthesis in Populus tomentosa
    International Journal of Molecular Sciences, 2021
    Co-Authors: Liangchen Yao, Mingyang Quan, Liang Xiao, Fangyuan Song, Yuanyuan Fang, Deqiang Zhang
    Abstract:

    Chlorogenic acid (CGA) plays a crucial role in defense response, immune regulation, and the response to abiotic stress in plants. However, the genetic regulatory network of CGA biosynthesis pathways in perennial plants remains unclear. Here, we investigated the genetic architecture for CGA biosynthesis using a metabolite-based genome-wide association study (mGWAS) and expression quantitative trait nucleotide (eQTN) mapping in a population of 300 accessions of Populus tomentosa. In total, we investigated 204 SNPs which were significantly associated with 11 metabolic traits, corresponding to 206 genes, and were mainly involved in metabolism and cell growth processes of P. tomentosa. We identified 874 eQTNs representing 1066 genes, in which the expression and interaction of causal genes affected phenotypic variation. Of these, 102 genes showed significant signatures of selection in three geographical populations, which provided insights into the adaptation of CGA biosynthesis to the local environment. Finally, we constructed a genetic network of six causal genes that coordinately regulate CGA biosynthesis, revealing the multiple regulatory patterns affecting CGA accumulation in P. tomentosa. Our study provides a multiomics strategy for understanding the genetic basis underlying the natural variation in the CGA biosynthetic metabolites of Populus, which will enhance the genetic development of abiotic-resistance varieties in forest trees.

  • Genetic Architecture and Genome-Wide Adaptive Signatures Underlying Stem Lenticel Traits in Populus tomentosa
    'MDPI AG', 2021
    Co-Authors: Jiaxuan Zhou, Mingyang Quan, Liang Xiao, Liangchen Yao, Dan Wang, Yuanyuan Fang
    Abstract:

    The stem lenticel is a highly specialized tissue of woody plants that has evolved to balance stem water retention and gas exchange as an adaptation to local environments. In this study, we applied genome-wide association studies and selective sweeping analysis to characterize the genetic architecture and genome-wide adaptive signatures underlying stem lenticel traits among 303 unrelated accessions of P. tomentosa, which has significant phenotypic and genetic variations according to climate region across its natural distribution. In total, we detected 108 significant single-nucleotide polymorphisms, annotated to 88 candidate genes for lenticel, of which 9 causative genes showed significantly different selection signatures among climate regions. Furthermore, PtoNAC083 and PtoMYB46 showed significant association signals and abiotic stress response, so we overexpressed these two genes in Arabidopsis thaliana and found that the number of stem cells in all three overexpression lines was significantly reduced by PtoNAC083 overexpression but slightly increased by PtoMYB46 overexpression, suggesting that both genes are involved in cell division and expansion during lenticel formation. The findings of this study demonstrate the successful application of an integrated strategy for dissecting the genetic basis and landscape genetics of complex adaptive traits, which will facilitate the molecular design of tree ideotypes that may adapt to future climate and environmental changes

  • transcriptome analysis and association mapping revealed the genetic regulatory network response to cadmium stress in Populus tomentosa
    Journal of Experimental Botany, 2020
    Co-Authors: Mingyang Quan, Yuepeng Song, Deqiang Zhang, Xin Liu, Liang Xiao, Panfei Chen, Fangyuan Song
    Abstract:

    Long non-coding RNAs (lncRNAs) play essential roles in plant abiotic stress responses, however, the lncRNA-mediated genetic networks response to cadmium (Cd) treatment remain elusive in trees, the promising phytoremediation candidates for Cd contamination. Here, we identified 172 Cd-responsive lncRNAs and 295 differentially expressed target genes in the leaves of Populus tomentosa under Cd treatment. Functional annotation revealed that these lncRNAs involved in various processes, including photosynthesis, hormone regulation, and phenylalanine metabolism. Association studies identified 78 significant associations, representing 14 Cd-responsive lncRNAs and 28 target genes for photosynthetic and leaf physiological traits. Epistasis uncovered 83 pairwise interactions among these traits, unveiling Cd-responsive lncRNA-mediated genetic networks for photosynthesis and leaf physiology in P. tomentosa. We then focused on the roles of two Cd-responsive lncRNA-gene pairs, MSTRG.22608.1-PtoMYB73 and MSTRG.5634.1-PtoMYB27, in Cd tolerance of Populus, and detected insertions/deletions within lncRNAs as polymorphisms driving target gene expression. LncRNAs genotype analysis and heterologous overexpressing PtoMYB73 and PtoMYB27 in Arabidopsis indicated their positive effects on enhancing Cd tolerance, photosynthetic rate, and leaf growth, and the potential interaction mechanisms of PtoMYB73 with abiotic stresses. Our study provides the genetic basis for Populus response to Cd treatment, facilitating genetic improvement of enhancing Cd tolerance in trees.

  • The Interactions between the Long Non-coding RNA NERDL and Its Target Gene Affect Wood Formation in Populus tomentosa
    Frontiers Media S.A., 2017
    Co-Authors: Mingyang Quan, Wan Shi, Deqiang Zhang
    Abstract:

    Long non-coding RNAs (lncRNAs) are important regulatory factors for plant growth and development, but little is known about the allelic interactions of lncRNAs with mRNA in perennial plants. Here, we analyzed the interaction of the NERD (Needed for RDR2-independent DNA methylation) Populus tomentosa gene PtoNERD with its putative regulator, the lncRNA NERDL (NERD-related lncRNA), which partially overlaps with the promoter region of this gene. Expression analysis in eight tissues showed a positive correlation between NERDL and PtoNERD (r = 0.62), suggesting that the interaction of NERDL with its putative target might be involved in wood formation. We conducted association mapping in a natural population of P. tomentosa (435 unrelated individuals) to evaluate genetic variation and the interaction of the lncRNA NERDL with PtoNERD. Using additive and dominant models, we identified 30 SNPs (P < 0.01) associated with five tree growth and wood property traits. Each SNP explained 3.90–8.57% of phenotypic variance, suggesting that NERDL and its putative target play a common role in wood formation. Epistasis analysis uncovered nine SNP-SNP association pairs between NERDL and PtoNERD, with an information gain of -7.55 to 2.16%, reflecting the strong interactions between NERDL and its putative target. This analysis provides a powerful method for deciphering the genetic interactions of lncRNAs with mRNA and dissecting the complex genetic network of quantitative traits in trees

  • Association studies in Populus tomentosa reveal the genetic interactions of Pto-MIR156c and its targets in wood formation
    Frontiers Media S.A., 2016
    Co-Authors: Mingyang Quan, Xiaohui Yang, Qingshi Wang, Yuepeng Song, Souksamone Phangthavong, Deqiang Zhang
    Abstract:

    MicroRNAs (miRNAs) regulate gene expression in many biological processes, but the significance of the interaction between a miRNA and its targets in perennial trees remains largely unknown. Here, we employed transcript profiling and association studies in Populus tomentosa (Pto) to decipher the effect of genetic variation and interactions between Pto-miR156c and its potential targets (Pto-SPL15, Pto-SPL20, and Pto-SPL25) in 435 unrelated individuals from a natural population of P. tomentosa. Single-SNP (single-nucleotide polymorphism) based association studies with analysis of the underlying additive and dominant effects identified 69 significant associations (P < 0.01), representing 51 common SNPs (minor allele frequency > 0.05) from Pto-MIR156c and its three potential targets, with six wood and growth traits, revealing their common roles in wood formation. Epistasis analysis uncovered 129 significant SNP-SNP associations with ten traits, indicating the potential genetic interactions of Pto-MIR156c and its three putative targets. Interestingly, expression analysis in stem (phloem, cambium, and xylem) revealed that Pto-miR156c expression showed strong negative correlations with Pto-SPL20 (r = -0.90, P < 0.01) and Pto-SPL25 (r = -0.65, P < 0.01), and a positive correlation with Pto-SPL15 (r = 0.40, P < 0.01), which also indicated the putative interactions of Pto-miR156c and its potential targets and their common roles in wood formation. Thus, our study provided an alternative approach to decipher the interaction between miRNAs and their targets and to dissect the genetic architecture of complex traits in trees

Zhong Chen - One of the best experts on this subject based on the ideXlab platform.

  • genome wide analysis of the poplar nf y gene family and its expression in floral bud development of Populus tomentosa
    Trees-structure and Function, 2020
    Co-Authors: Kai Gao, Wasif Ullah Khan, Xiong Yang, Xiaoyu Yang, Tianyun Zhao, Zhong Chen
    Abstract:

    Key message The NF-Y gene family was identified and characterized in Populus trichocarpa by genome-wide analysis. Expression of PtoNF-Y was analyzed during floral bud development in Populus tomentosa.

  • a global view of transcriptome dynamics during male floral bud development in Populus tomentosa
    Scientific Reports, 2018
    Co-Authors: Kai Gao, Xiaoyu Yang, Tianyun Zhao, Zhong Chen, Pian Rao, Xiong Yang
    Abstract:

    To obtain a comprehensive overview of the dynamic transcriptome during male floral bud development in Populus tomentosa, high-throughput RNA-seq was conducted during eight flowering-related stages. Among the 109,212 de novo assembled unigenes, 6,959 were differentially expressed during the eight stages. The overrepresented classed of genes identified by Gene Ontology (GO) enrichment included ‘response to environmental stimuli’ and ‘plant-type spore development’. One-third of the differentially expressed genes were transcription factors (TFs). Several genes and gene families were analyzed in depth, including MADS-box TFs, Squamosa promoter binding protein-like family, receptor-like kinases, FLOWERING LOCUS T/TERMINAL-FLOWER-LIKE 1 family, key genes involved in anther and tapetum development, as well as LEAFY, WUSCHEL and CONSTANS. The results provided new insights into the roles of these and other well known gene families during the annual flowering cycle. To explore the mechanisms regulating poplar flowering, a weighted gene co-expression network was constructed using 98 floral-related genes involved in flower meristem identity and flower development. Many modules of co-expressed genes and hub genes were identified, such as APETALA1 and HUA1. This work provides many new insights on the annual flowering cycle in a perennial plant, and a major new resource for plant biology and biotechnology.

  • Variation in the Growth Traits and Wood Properties of Hybrid White Poplar Clones
    MDPI AG, 2015
    Co-Authors: Youming Dong, Zhong Chen, Bingqi Lei, Weihua Liao, Kai Gao
    Abstract:

    The physical and chemical properties of poplar clones largely determine their suitability for different applications. The main objective of this study was to investigate clonal variation in four hybrid poplar clones grown at three sites in North China and identify the superior clone. Study materials were collected from four clones of hybrid white poplar: Populus tomentosa “LM50”, used as the control; two clones (Yiyang-1 and Yiyang-2), new hybrids of (P. tomentosa × P. bolleana) × P. tomentosa “Truncata”; and Yiyang-3, a new hybrid of (P. tomentosa × P. bolleana) × P. tomentosa “LM50”. In total, 192 individuals from four hybrid clones were randomly chosen for sampling. The growth traits of four 7-year-old clones were examined at three sites. We also measured the wood properties of four 6-year-old clones at the Fengfeng nursery. Variation in the growth traits and the ranking of stem volumes differed among sites. Fiber traits and wood chemical components showed significant interclonal variation. With regard to the comprehensive growth rate, cellulose content, holocellulose content, and fiber traits, Yiyang-1 exhibited the best performance among the four hybrid poplar clones, indicating its utility as a raw material for pulp and papermaking

  • A Novel Moderate Constitutive Promoter Derived from Poplar (Populus tomentosa Carrière)
    2013
    Co-Authors: Zhong Chen, Jia Wang, Dong-qing Cui, Jun-mei Liu
    Abstract:

    Abstract: A novel sequence that functions as a promoter element for moderate constitutive expression of transgenes, designated as the PtMCP promoter, was isolated from the woody perennial Populus tomentosa. The PtMCP promoter was fused to the GUS reporter gene to characterize its expression pattern in different species. In stable Arabidopsis transformants, transcripts of the GUS reporter gene could be detected by RT-PCR in the root, stem, leaf, flower and silique. Further histochemical and fluorometric GUS activity assays demonstrated that the promoter could direct transgene expression in all tissues and organs, including roots, stems, rosette leaves, cauline leaves and flowers of seedlings and maturing plants. Its constitutive expression pattern was similar to that of the CaMV35S promoter, but the level of GUS activity was significantly lower than in CaMV35S promoter::GUS plants. We also characterized the promoter through transient expression in transgenic tobacco and observed similar expression patterns. Histochemical GUS staining and quantitative analysis detected GUS activity in all tissues and organs of tobacco, including roots, stems, leaves, flower buds and flowers, but GUS activity in PtMCP promoter::GU