Paulownia Fortunei Research Articles

Physiological and enrichment characteristics of Paulownia fortunei seedlings under zinc, cadmium and their combined stress

The hydroponic culture test method was used to study the physiological and biochemical responses of Paulownia fortunei seedlings under Zn stress, Cd stress, and combined Zn and Cd stress as well as changes in the enrichment and transfer characteristics of heavy metals. Under single and combined heavy metal stress, the biomass, plant height, and peroxidase (POD) activity of P. fortunei decreased as the treatment concentration increased. Combined Zn and Cd affected adversely plant height and biomass. As the concentration of Zn increased when applied alone, the chlorophyll content and catalase (CAT) activity of P. fortunei first increased and then decreased, the superoxide dismutase (SOD) activity increased, and the aboveground malondialdehyde (MDA) content first decreased and then increased. As the concentration of Cd increased when applied alone, chlorophyll content and CAT activity increased, and SOD activity and aboveground MDA content first increased and then decreased. Under both Cd and Zn, the physiological response was more complex. Cd in the seedlings of P. fortunei was concentrated in the root. In contrast, Zn was concentrated in the upper part of the ground, and its transfer coefficient was greater than 1.00. Thus, the addition of Zn promotes the transfer of heavy metals to the above-ground portions of plants. Generally, P. fortunei can effectively promote ecological restoration under complex forms of heavy metal pollution.

Genomic insights into the fast growth of paulownias and the formation of Paulownia witches' broom

Paulownias are among the fastest growing trees in the world, but they often suffer tremendous loss of wood production due to infection by Paulownia witches' broom (PaWB) phytoplasmas. In this study, we have sequenced and assembled a high-quality nuclear genome of Paulownia fortunei, a commonly cultivated paulownia species. The assembled genome of P. fortunei is 511.6 Mb in size, with 93.2% of its sequences anchored to 20 pseudo-chromosomes, and it contains 31 985 protein-coding genes. Phylogenomic analyses show that the family Paulowniaceae is sister to a clade composed of Phrymaceae and Orobanchaceae. Higher photosynthetic efficiency is achieved by integrating C3 photosynthesis and the crassulacean acid metabolism pathway, which may contribute to the extremely fast growth habit of paulownia trees. Comparative transcriptome analyses reveal modules related to cambial growth and development, photosynthesis, and defense responses. Additional genome sequencing of PaWB phytoplasma, combined with functional analyses, indicates that the effector PaWB-SAP54 interacts directly with Paulownia PfSPLa, which in turn causes the degradation of PfSPLa by the ubiquitin-mediated pathway and leads to the formation of witches' broom. Taken together, these results provide significant insights into the biology of paulownias and the regulatory mechanism for the formation of PaWB.

Flavanones from the fruit extract of Paulownia fortunei

Two new prenylated flavanonols, named as fortunones A (1) and B (2), and one new geranylated flavanone, named as fortunones C (3), were isolated from the fruits of Paulownia fortunei (Seem.) Hemsl. Their structures were elucidated distinctly according to their UV, MS, NMR, and CD spectra. Structural modifications on prenyl and geranyl groups in these isolated compounds were uncommon for Paulownia flavanones. Only compounds 1 and 3 showed weak antioxidant effect on human umbilical vein endothelial cells injury induced by H2O2.

Five new phenylpropanoid glycosides from the flowers of Paulownia fortunei and their antioxidant activities

• Five new phenylpropanoid glycosides were isolated from the flowers of Paulownia fortunei. • Their structures were elucidated based on spectroscopic data analyses. • Compound 1 , 3 , 5 exhibited excellent antioxidant activities on NRK52e cell compared with a positive control. In this study, we focused on the antioxidant activities in NRK52e cells, a rat renal proximal tubular cell line, of five new phenylpropanoid glycosides, paulowninosides B–F (Compounds 1 – 5 ), which were isolated from the n -BuOH soluble part of the 50 % acetone-H 2 O extract of the flowers of Paulownia fortunei. The structures of the compounds were determined by extensive spectroscopic analyses (UV and IR spectroscopy, HR-ESI-MS, 1D-, 2D-NMR). The levels of antioxidant activities of the compounds were determined by real-time cell analysis (RTCA) of NRK52e cells that underwent H 2 O 2 -induced oxidative injury. Compounds 1 , 3 and 5 exhibited excellent antioxidant activities compared with control group.

Genome-wide identification of candidate genes related to disease resistance and high biomass in tetraploid Paulownia

Polyploidization is an important feature of speciation that results from genome doubling. Tetraploid plants often have better physical characteristics than their diploid counterparts, and Paulownia is no exception. In our previous studies, several genes related to timber quality and abiotic stress resistance were identified in Paulownia tomentosa and Paulownia fortunei. However, the genes related to disease resistance and high biomass were not confirmed. In this study, small RNA and transcriptome sequencing were performed to analyze changes in microRNA (miRNA) and mRNA expression levels in tetraploid Paulownia tomentosa × Paulownia fortunei and Paulownia australis and their diploid counterparts. A total of 930 common differentially expressed genes and 66 (19 known and 47 novel) common differentially expressed miRNAs were detected in the two tetraploid vs. diploid comparisons. Twenty-two miRNA target genes were predicted, and the regulatory functions of the miRNA–target gene pairs were analyzed, of which the novel miR327- SGT1 HOMOLOG PROTEIN At5g65490 (PAU019930.1) and pau-miR2111a-MYB-RELATED TRANSCRIPTION FACTOR (PAU011118.1) interacting pairs were predicted to co-regulate disease resistance in tetraploid Paulownia. The pau-miR157i-SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE 15 (PAU009402.1) and novel miR10-PUTATIVE PENTATRICOPEPTIDE REPEAT-CONTAINING PROTEIN At5g65820 (PAU012281.1) interacting pairs were predicted to co-regulate high biomass in tetraploid Paulownia. The expression trends of the miRNA and candidate target genes were validated by qRT-PCR. The results will help to accelerate genetic gain in Paulownia breeding programs to develop superior varieties.

Whole-genome landscape of H3K4me3, H3K36me3 and H3K9ac and their association with gene expression during Paulownia witches' broom disease infection and recovery processes.

Histone methylation and acetylation participate in the modulation of gene expression. Here, chromatin immunoprecipitation sequencing (ChIP-Seq) was used to determine genome-wide patterns of three histone modifications, H3K4me3, H3K36me3, and H3K9ac (associated with actively expressed genes) and their associations with gene expression in Paulownia fortunei following phytoplasma infection and recovery from Paulownia witches' broom (PaWB) disease after methyl methane sulfonate treatment. The three histone marks were preferentially deposited in genic regions, especially downstream of transcription start sites, and were highly concurrent with gene expression. Genes with all three histone marks exhibited the highest expression levels. Based on the comparison scheme, we detected 365, 2244, and 752 PaWB-associated genes with H3K4me3, H3K36me3, and H3K9ac marks, separately. KEGG pathway analysis showed that these genes were involved in plant-pathogen interaction, plant hormone signal transduction, and starch and sucrose metabolism. A small proportion of differentially modified genes showed changes in expression in response to phytoplasma infection, including genes involved in calcium ion signal transduction, abscisic acid signal transduction, and ethylene biosynthesis. This comprehensive analysis of genome-wide histone modifications and gene expression in Paulownia following phytoplasma infection provides new insights into the epigenetic responses to phytoplasma infection and will be useful for further studies on epigenetic regulation mechanisms in plants under biotic stress.

Genome-wide DNA methylation analysis of paulownia with phytoplasma infection.

DNA methylation, an important epigenetic modification, regulates a wide range of biological processes. Previous MSAP results showed that the occurrence of PaWB related to changes of DNA methylation level; however, the relationship between DNA methylation and gene expression remains obscure in paulownia. Therefore, in the present study, we applied WGBS and RNA-seq techniques to investigate the DNA methylation and gene expression changes between healthy Paulownia fortunei seedlings and the phytoplasma-infected ones. A map of methylated cytosines at the single base pair resolution of paulownia was constructed. Compared to the healthy seedlings, the DNA methylation level increased after phytoplasma infection, and the change of mCHH was the main methylation pattern. DMR analysis showed that 422,662 DMRs in the genome were identified, in which, 27,871 DMR-associated genes were differentially expressed. Finally, 436 genes with significant differences in their methylation levels and mRNA expression profiles were identified through integrated analysis of the DNA methylomic and transcriptomic. KEGG pathway analysis revealed that these genes are mainly involved in plant hormone signal transduction, carbon metabolism, and starch and sucrose metabolism pathways. Two of DMR-associated genes were verified by BS- PCR. Finally, we selected TRP 1 and R2R3-MYB protein were closely related to the occurrence of PaWB. Our findings provide valuable insight into the mechanism of PaWB at the epigenetic level.

Physical Properties of Juvenile Wood of Two Paulownia Hybrids

There is a growing trend in the world of planting fast growing species (rotations 5 to 10 years). Their primary purpose is the production of wood fibers and biomass, but they certainly represent the potential in making solid wood products as well. One of the fast-growing species is Paulownia sp., a species of extremely fast growing wood. Plantation breeding of Paulownia sp. in Croatia is increasing, although there is a little knowledge about the technical properties of Paulownia wood and its end use is questionable. This paper presents preliminary results of some physical properties of juvenile wood of two Paulownia hybrids planted in the area near the town of Glina in the Republic of Croatia. One hybrid is 9501 ((Paulownia fortunei × Paulownia elongata) × (Paulownia fortunei × Paulownia tomentosa)) and the other hybrid is Shan Tong (Paulownia fortunei × Paulownia tomentosa). The aim of this study was to investigate physical properties of juvenile wood of two Paulownia hybrids from one site in Croatia, to determine differences in physical properties of wood between two hybrids and to evaluate the correlation between density and shrinkages of each hybrid. Significant differences in oven dry density, basic density and density at maximum MC, between the two hybrids were determined. There is no statistically significant difference in longitudinal, radial, tangential and volumetric shrinkages between the two hybrids.

The potential of Paulownia fortunei seedlings for the phytoremediation of manganese slag amended with spent mushroom compost

The use of phytoremediation was an efficient strategy for the restoration of mine slag and the addition of modifier was favorable for improving the phytoremediation efficiency. Herein, spent mushroom compost (SMC) was added in manganese (Mn) slag to reveal the phytoremediation potential of Paulownia fortunei seedlings. The transportation, subcellular distribution and chemical forms of Mn in P. fortunei, the diurnal variation of photosynthesis and antioxidant enzyme activities in P. fortunei leaves were measured to reveal the effect of SMC (mass ratios of 10%, M+) on the phytoremediation of Mn slag. Results showed that the addition of SMC increased the accumulation content of Mn by 408.54% due to the increased biomass of P. fortunei seedlings. After SMC amendment, the maximum net photosynthetic rate (Pn) increased and the superoxide dismutase (SOD) activities decreased significantly (p<0.05), which was beneficial to the tolerance of leaves to Mn stress. SMC amendment maintained the cell structural integrity of P. fortunei seedlings observed by transmission electron microscope (TEM). Additionally, SMC amendment decreased the damage level of Mn to the cell of P. fortunei seedlings by using function groups (-CH3 and -COOH) to bond Mn in the cell walls and vacuoles. SMC amendment reduced the Mn toxicity to P. fortunei seedlings and improved the phytoremediation capacity.

Metagenomic analysis of bacterial and fungal community composition associated with Paulownia elongata × Paulownia fortunei

The dynamics and interactions of microbial communities in Paulownia’s life cycle are poorly understood. The main goal of this study was to compare the rhizospheric soil and endophytic microbiome and mycobiome of hybrid Paulownia elongata and Paulownia fortunei. The comparison was based on highly efficient Illumina MiSeq sequencing of bacteria and fungi from the rhizosphere and endosphere of bioenergetic trees P. elongata x P. fortunei. The general richness of bacteria and rhizospheric fungi (based on Chao 1, Shannon, and Simpson indicators) was higher than in endosphere samples from the same plants. Actinobacteria and Proteobacteria were dominant in the rhizosphere and endosphere of plants in healthy conditions. The rhizosphere fungal communities in both trials were dominated by Ascomycota, Mortierellomycota, and Basidiomycota. Most root endophytes came from Olpidiomycota, Oomycota, and Ascomycota, while most leaf endophytes were from Ascomycota and Basidiomycota. This study was the first report on the composition of bacteria and fungi associated with the endosphere and rhizosphere of Paulownia trees. These studies showed that bacterial and fungal communities from the rhizosphere and endosphere were separate communities. It also showed that the health conditions of trees did not affect the composition of endophytic microorganisms in Paulownia tissues.

Effect of the root biotechnical characteristics of Alnus subcordata, Paulownia fortunei and Populus deltoides on the soil mechanics

The effect of root reinforcement depends on the biotechnical characteristics of the root system including the tensile strength of individual roots, the root density and the distribution of the root system in the soil. This research was conducted in the Hyrcanian forest in Iran, where shallow landslides are frequent due to road construction. The effect of the root biotechnical characteristics of Alnus subcordata, Paulownia fortunei and Populus deltoides each one in 2-, 10- and 15-year-old plantations was assessed. The profile trenching method was used in this study to obtain the root area ratio of individual species by counting the number of roots and measuring the root diameter. For each species, single root specimens were sampled and tested for tensile tests in the laboratory using the standard Instron apparatus. The natural moisture content (two weeks after rainfall), Atterberg limits, shear strength of the soil were determined for plantations, stable and unstable sites. Results of this study indicated that plastic index and internal friction angle decreased with increasing root diameter rate. Moreover, internal friction angle and cohesion increased with increasing root area ratio and root diameter and density index. Tensile strength of roots decreased with increasing stand age. The highest and the lowest tensile strengths among species were observed for Paulownia fortunei and Populus deltoides, respectively. The findings of this research contribute to expanding the knowledge of root biotechnical properties of some tree species and to the choice of the most appropriate species for improving plastic index and shear strength in landslide prone areas.

In Vitro Propagation Protocols and Variable Cost Comparison in Commercial Production for Paulownia tomentosa × Paulownia fortunei Hybrid as a Renewable Energy Source

In this elaboration, effective methods of in vitro propagation of a Paulownia tomentosa × Paulownia fortunei hybrid are presented, and the variable costs of commercial production evaluated. Plant regeneration of the P. tomentosa × P. fortunei hybrid was achieved through organogenesis in nodal explants. Different concentrations of BAP (6-benzylaminopurine), 0.2, 0.5, 1 mg/L, and light conditions were investigated. The best results were obtained using a half-strength MS medium containing 0.5 mg/L BAP. In standard light conditions, 2 shoots were grown with 3.5 culturable nodes on each, and in 70% reduced light, 2 new shoots were grown with 6 culturable nodes on each. Rooting was successfully achieved when using a hormone-free half-strength MS medium containing vitamin, and 2% sucrose with 95% efficiency. Acclimatization and survival were shown to be 90% in regenerated plants. The cost of production of a single plant of P. tomentosa × P.fortunei hybrid grown in standard light conditions was $0.084 and $0.082 when grown in 70% reduced light where only variable costs were considered. Two major factors affecting P. tomentosa × P fortunei hybrid micropropagation is labor, materials and chemicals. Focusing on reducing this cost can highly lower plantlet price.

Accumulation and subcellular distribution of heavy metal in Paulownia fortunei cultivated in lead-zinc slag amended with peat

The contamination of toxic heavy metals was a major issue of concern in the last century. A fast-growing metal-accumulating woody plant is a promising approach for the remediation of toxic heavy metal. In this study, the transportation of heavy metals (Pb, Zn, Cu, and Cd) in Paulownia fortunei cultivated in lead-zinc slag amended with different mass ratios of peat (CK: 0; T1: 10%; T2: 20%; T3: 30%) was investigated, as well as the subcellular distribution of Pb, Zn, Cu, and Cd in Paulownia fortunei. The results showed that the accumulation content of Pb, Zn, Cu, and Cd in Paulownia fortunei were increased with peat amendment, which was in the range of 4.216 ∼ 6.853, 20.905 ∼ 23.017, 1.898 ∼ 2.572, and 0.530 ∼ 0.616 mg/pot, respectivly. The experimental group with 30% dose of peat showed the best performance on the accumulation content of Pb, Zn, Cu, and Cd, with increase rates (compared to control) of 4.088, 10.573, 1.360, and 0.294 mg/pot, respectively. The bioconcentration, translocation and transfer quantity factor of Pb, Zn, Cu, and Cd were less than 1. Fixation of cell wall and compartmentalization of vacuolar appeared to play an important role in reducing the toxicity of Pb, Zn, Cu, and Cd.

Genome-wide analysis of three histone marks and gene expression in Paulownia fortunei with phytoplasma infection

BackgroundPaulownia withes’-broom (PaWB) disease caused by phytoplasma is a serious infectious disease for Paulownia. However, the underlying molecular pathogenesis is not fully understood. Recent studies have demonstrated that histone modifications could play a role in plant defense responses to pathogens. But there is still no available genome-wide histone modification data in non-model ligneous species infected with phytoplasma.ResultsHere, we provided the first genome-wide profiles of three histone marks (H3K4me3, H3K36me3 and H3K9ac) in Paulownia fortunei under phytoplasma stress by using chromatin immunoprecipitation sequencing (ChIP-Seq). We found that H3K4me3, H3K36me3 and H3K9ac were mainly enriched in the genic regions in P. fortunei with (PFI) and without (PF) phytoplasma infection. ChIP-Seq analysis revealed 1738, 986, and 2577 genes were differentially modified by H3K4me3, H3K36me3 and H3K9ac marks in PFI under phytoplasma infection, respectively. The functional analysis of these genes suggested that most of them were mainly involved in metabolic pathways, biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, plant-pathogen interaction and plant hormone signal transduction. In addition, the combinational analysis of ChIP-Seq and RNA-Seq showed that differential histone methylation and acetylation only affected a small subset of phytoplasma-responsive genes.ConclusionsTaken together, this is the first report of integrated analysis of histone modifications and gene expression involved in Paulownia-phytoplasma interaction. Our results will provide the valuable resources for the mechanism studies of gene regulation in non-model plants upon pathogens attack.

Four C-geranyl flavonoids from the flowers of Paulownia fortunei and their anti-inflammatory activity

Four new C-geranyl flavonoids, paulownione D-G (1–4) were isolated from the 50% acetone-H2O extract of the flowers of Paulownia fortunei. The structures of the compounds were determined by extensive spectroscopic analyses (UV, IR, HR-ESI-MS, 1D and 2D NMR). All of the compounds (1–4) exhibited potent protection effects in H9c2 cardiocytes against the lipopolysaccharide (LPS)-induced inflammation.

A polysaccharide found in Paulownia fortunei flowers can enhance cellular and humoral immunity in chickens.

A water-soluble polysaccharide known as Paulownia fortunei flower polysaccharide (PFFPS) was isolated from the flowers of Paulownia fortunei. Gel permeation chromatography (GPC) analysis showed that approximately 92.5% of PFFPS fractions had molecular weights under 500 kDa. High performance liquid chromatograph (HPLC) analysis revealed that PFFPS was composed of 10 monosaccharides, including galactose (28.61%), rhamnose (18.09%), glucose (15.21%), and arabinose (15.91%). Fourier transform infrared (FT-IR) spectra revealed the specific absorption peaks of the polysaccharide. Using in vivo tests in chickens, we found that even very low doses of PFFPS could significantly promote the development of the immune organs, increase the quantity of leukocytes and the ratio of lymphocytes, and improve antibody titers against Newcastle disease virus (NDV). In addition, PFFPS also increased the concentrations of IL-2 and IFN-γ, as well as the content of SIgA in the duodenum. Furthermore, PFFPS was found to be able to relieve immunosuppression caused by cyclophosphamide (CTX). This study therefore suggests that PFFPS may be a valuable component of new immunopotentiator and/or adjuvant for the livestock and poultry industries.

Effect of Supercritical Carbon Dioxide Treatment on Gas Permeability of Paulownia Fortunei Heartwood and Sapwood

Many wood species are resistant to penetration of liquids. Impermeability can affect a variety of properties including the ability to deliver preservatives, adhesive bonding, and coating applications. Developing methods for altering this characteristic could help in utilization of impermeable species. One method for altering wood properties is through the use of supercritical carbon dioxide (SC-CO2) which can solubilize a wide range of organic compounds. In this report, we examined the ability of varying SC-CO2 conditions to improve the permeability of Paulownia fortunei. All of the processes tested improved gas permeability and most reduced the frequency of tyloses in the vessels. The results suggest that SC-CO2 could be used to modify the permeability of this species.

Influence of Species, Clone, Propagation Method, and Animal Waste Application during Establishment on Growth and Productivity of 21-Year-Old Paulownia Trees

Paulownia elongata, Paulownia fortunei, and Paulownia × 'Henan 1' were grown for 21 years to determine growth and productivity potential of Paulownia in North Carolina, USA. One site included P. elongata only and was designed to test variability among clones within the species and the influence of application of dairy cow or poultry litter during the first six years. A second site was used to examine influence of species, clone, and propagation method. Species and clone within species frequently influenced tree performance, indicating that the planting of select clones could increase yields. By using the best approximately one-third of clones rather than all clones, tree survival could increase from 74% to 98%, and individual tree productivity as estimated by stem dry mass could increase by 21%. Trees of all three species grown from seed had lower survival, and seed-propagated trees that survived had inferior growth compared to trees of the same species grown from rooted shoot cuttings or microshoots from tissue culture. Application of dairy cow waste or poultry litter during the first six years did not influence tree survival or height to live crown, but early application of either animal waste resulted in taller trees compared to the control trees. Trees established with poultry litter applications had greater stump diameter, diameter breast height, stem volume, and stem dry mass than trees in the dairy cow waste or water-only control treatments.

桐-药复合经营模式下泡桐丛枝菌根真菌群落结构特征

桐-药复合经营模式下泡桐丛枝菌根真菌群落结构特征

A commercial laccase-mediator system to delignify and improve saccharification of the fast-growingPaulownia fortunei(Seem.) Hemsl.

AbstractIt was demonstrated for the first time that a laccase-based enzymatic pretreatment is able to delignify fast-growing paulownia species. The treatment was performed with a commercial low-redox potential laccase isolated fromMyceliophthora thermophila(Apinis) Oorschot and methyl syringate (MeS) as a natural phenolic mediator. Up to 24% lignin removal was attained by the laccase-MeS treatment (L/MeS), followed by alkaline peroxide extraction in a multistage sequence. The reduction in lignin content was accompanied by a significant improvement in the subsequent enzymatic saccharification, with increases of up to 38% glucose and 34% xylose yields. The structural modifications of the lignin were analyzedin situby two dimensional-nuclear magnetic resonance (2D-NMR) spectroscopy. A considerable removal of guaiacyl and syringyl lignin units with respect to the carbohydrate signals was visible as well as the cleavage of β-O-4′, β-5′ and β-β′ linkages leading to elevated amounts of Cα-oxidized guaiacyl and syringyl units. The presence of oxidized lignin compounds in the filtrates of the enzymatic treatments – such as vanillin, vanillic acid, syringaldehyde and syringic acid – conclusively demonstrates the ability of L/MeS treatment to oxidize and depolymerize the lignin in paulownia wood.