Paulownia Species Research Articles

Topochemical kinetic mechanism of cellulase hydrolysis on fast-growing tree species. COST Action FP1105

Abstract Optimization of the lignocellulosic bioconversion by cellulolytic enzymes requires good knowledge of reaction kinetics. In the present paper, the investigations of the kinetics have been performed on the fast-growing tree species of poplar, paulownia, willow and black locust, which were pretreated by steam explosion (SE), and bleached kraft pulp (BKP) made of a hardwood mixture. The applicability of different kinetic equations referring to diffusion, topochemical and other heterogeneous catalytic processes was examined, and it was found that the enzyme process is best described by the modified Prout-Tompkins topochemical equation. According to that kinetic model, the hydrolysis rate depends on the amount of the substrate left and the inhibition of the enzyme by the product formed and, moreover, on the combination of chemical interaction and diffusion processes. There is a compensation effect between activation energy and pre-exponential factor and there are correlations between rate constant, power factor, and wood density. The mechanisms of cellulase hydrolysis of BKP- and SE-treated fast-growing tree species are very similar. The results shows that the structural features of the lignocellulosic material are the controlling factor on the type of the kinetic mechanism. The obtained temperature-time dependence of degree of enzyme hydrolysis is useful for simulation and control of the process.

Irrigation effects on diameter growth of 2-year-old Paulownia tomentosa saplings

Species of Paulownia are fast-growing trees that are planted in many countries in green spaces and agroforestry systems. We studied the influence of irrigation on the diameter growth of 2-year-old Paulownia tomentosa saplings planted in 3 m × 3 m grids at Nazlou Campus of Urmia University, Iran. Completely randomized experimental design was used with four irrigation amount, viz. 10, 15, 20 and 25 L, and three irrigation intervals, viz. 3- and 6-days, in 8 replications. During the growth season, we measured collar diameters of all saplings at the end of each month. Diameter growth declined with reduced irrigation amount and increased irrigation interval. The lowest average diameter growth (9 mm) was recorded for 10 L water at 6-day intervals and maximum average diameter growth (28.7 mm) was recorded for 25 L volume at 3-day intervals. The latter treatment resulted in significantly greater diameter growth than any other treatment (except 20 L at 3-day intervals). More than 80 % of diameter growth was achieved in the first 3 months. Therefore, it is essential to irrigate with 25 L of water at 3-day intervals during the first three growth months to achieve maximum diameter growth for 2-year-old P. tomentosa saplings.

Impact of Hot-Water Extraction on Acetone-Water Oxygen Delignification of Paulownia Spp. and Lignin Recovery

A hardwood-based biorefinery process starting with hot-water extraction (HWE) is recommended in order to remove most of the hemicelluloses/xylans before further processing. HWE may be followed by delignification in acetone/water in the presence of oxygen (AWO) for the production of cellulose and lignin. In this study, the HWE-AWO sequence was evaluated for its effectiveness at removing lignin from the fast-growing species Paulownia tomentosa (PT) and Paulownia elongata (PE), in comparison with the reference species, sugar maple (Acer saccharum, SM). HWE might lead to a remarkable increase in lignin accessibility, and as a result, a greater AWO delignification degree was observed for extracted PT, PE, and SM than for unextracted ones. Organosolv lignin was recovered from the spent liquor of AWO delignification of PT with/without prior HWE and characterized to evaluate the benefits of HWE on the lignin structure and purity. The lignin recovered from the spent liquor of HWE-AWO sequence is of higher purity and lighter color than that recovered from the AWO spent liquor. These properties along with low sulfur content are desirable for lignin high-value applications.

A Review of <i>Paulownia</i> Biotechnology: A Short Rotation, Fast Growing Multipurpose Bioenergy Tree

Paulownia is a genus of fast-growing and multipurpose tree species that is native to China. Due to their rapid growth and value in the timber market, many Paulownia species are cultivated in several temperate zones worldwide. Economic importance of Paulownia is increasing as new uses and related products are developed. It is also suitable as a lignocellulosic feedstock crop for the bioethanol industry in the Southeastern USA. A number of Paulownia species are valuable sources of secondary metabolites including flavonoids with high antioxidant activities. A high demand for planting material in domestic and international markets for afforestation and bioenergy production has necessitated the development of efficient micropropagation protocols for rapid and mass propagation of Paulownia. Over the past several decades, research on Paulownia species has been conducted to develop micropropagation, somatic embryogenesis and genetic transformation protocols for use in agroforestry and reforestation programs. Given the economic importance and current and potential future uses of Paulownia, this paper reviews the development of biotechnological approaches for plant propagation and genetic improvement, and antioxidant potential of secondary metabolites occurring in species.

Short Communication Microsatellite markers in Paulownia kawakamii (Scrophulariaceae) and cross-amplification in other Paulownia species

Paulownia kawakamii is a fast-growing timber tree. In this study, 21 primer sets were developed using an enriched genomic library. The genetic diversity was measured in one P. kawakamii population. The number of alleles per locus ranged from 2 to 19. The observed and expected heterozygosities varied from 0.158 to 0.842 (mean = 0.421) and from 0.376 to 0.952 (mean = 0.771), respectively. All 21 loci were also polymorphic in closely related species (P. tomentosa, P. elongata, and P. fortunei). The described markers will be useful in future population genetic studies and molecular breeding of these Paulownia species.

МОЛЕКУЛЯРНА ДИФЕРЕНЦИАЦИЯ НА ГЕНОТИПОВЕ ОТ РОД

Paulownia is the only genus in Paulowniaceae family and encompasses several species with similar characteristics. In the last years the interest for industrial use of the genus is rising in Bulgaria in relation to the possibilities for using it as bioenergy source and a raw material for wood industry. Knowledge of the genus however is very limited and poses difficulties even when species and hybrids that are marketed in the country are to be differentiated. Therefore a system for adequate identification of different genotypes is not just of scientific, but of practical interest as well. Due to the lack of adequately described methods for molecular differentiation of the species of Paulownia sp. the present study aims at assessing the efficiency of using ISSR markers within this genus and to make an attempt to differentiate the genotypes within the group of species and hybrids, that are available in vitro at the Laboratory of Plant biotechnology of the Agricultural University of Plovdiv.

Phenolic extractives with chemotaxonomic significance from the bark of Paulownia tomentosa var. tomentosa

Chemotaxonomy, also known as chemosystematics, can be regarded as a hybrid science which can classify plants based on their unique extractives (secondary metabolites). In this work, we investigated the chemotaxonomic marks of Paulownia species by studying the extractives of Paulownia tomentosa (Thunb.) Steud. var. tomentosa, a hardwood species widely used in Chinese medicine and pulping industries. Nine phenolic extractives, including two flavonoids (naringenin (1), and quercetin (2)), two phenolic acids (cinnamic acid (3), and gallic acid (4)), and five phenylpropanoid glycosides (cistanoside F (5), acteoside (6), isoacteoside (7), campneoside II (8), and isocampneoside II (9)), were isolated from the n-BuOH soluble fraction of P. tomentosa var. tomentosa bark, by repeated sephadex LH-20 open column chromatography coupled by Thin Layer Chromatography detection. The structures of the phenolic extractives were elucidated and characterized on the basis of their spectroscopical data and physiochemical properties. This was the first time to report the nine extractives from P. tomentosa var. tomentosa bark. Our chemotaxonomic analysis demonstrated that phenylpropanoid glycosides in P. tomentosa var. tomentosa were interesting and phenylpropanoid glycosides may possibly be considered as a useful chemotaxonomic marker within the species of Paulownia.

Paulownia as a raw material for the production of pulp by soda–anthraquinone cooking with or without previous autohydrolysis

AbstractBACKGROUND: A central composite experimental design and multiple regression were used to model the production of pulp and paper sheets from a Paulownia fortunei × tormentosa × elongata trihybrid clone. Also, the same experiments were carried out with the solid phase after autohydrolysis of the raw material.RESULTS: The results were compared with those obtained from the solid phase remaining after autohydrolysis of the raw material with a view to optimizing the use of hemicelluloses and cellulose by fractionation. Pulp and paper sheets from the trihybrid clone surpass those from other Paulownia species such as P. fortunei and P. elongata in physical properties such as tensile index (11.6–49.1 Nm g−1), burst index (0.23–2.41 MPa m2 kg−1), tear index (0.71–3.03 mN m2 g−1) and intrinsic viscosity (427–958 cm3 g−1).CONCLUSIONS: The solid phase obtained by autohydrolysis of the Paulownia trihybrid provides pulp and paper sheets comparable in strength‐related properties with those of pulp directly produced from the raw material, but using substantially milder operating conditions and with the added advantage that the autohydrolysis treatment provides highly valorizable liquor. Copyright © 2011 Society of Chemical Industry

The influence of sanding system on wetting of Paulownia siebold et zucc.

This paper presents the research of influence of wood surface preparation on the wetting ability of polyurethane coatings, by the method of contact angle. The samples were made of two species of Paulownia (Paulownia elongata and Paulownia fortunei). All the samples were processed by planing (molding). After molding, the samples were arranged in groups and sanded. In relation with wood grain direction, each group had a particular system of sanding, based on the numbering of sanding paper, program of displacement of sanding papers with different numbering and the direction of sanding. The quality of wood surface after sanding was expressed by the values of roughness parameters in the system 'M': Ra, Rz, Rv, Rp and Rt. The contact angle was measured using transparent polyurethane (PU) coating and distilled water. The influence of the system of sanding on the values of contact angle was analyzed by roughness parameter Ra.

Contents of the heavy metals nickel and lead in leaves of Paulownia elongata S.Y. Hu and Paulownia fortunei Hems. in Serbia

A comparative study was carried out on the capabilities of the two species Paulownia elongata S. Y. Hu and Paulownia fortunei Hems. as biomonitors of atmospheric (and soil) heavy-metal pollution. Research on content of the heavy metals nickel (Ni) and lead (Pb) in leaves of the species Paulownia elongata growing under urban and suburban conditions with the comparison to the concentration of these elements in leaves of the species Paulownia elongata and Paulownia fortunei on an experimental plot in Bela Crkva showed average nickel concentrations of 2.7 ?g/g on the experimental plot in Bela Crkva, Serbia, twice as low as the concentrations measured under extreme urban conditions (6.62 ?g/g, or 4.54 ?g/g in the immediate vicinity of suburban traffic lines). Inasmuch as Paulownia elongata endures urban conditions well, it can be recommended for cultivation in parks, tree alleys, and wind-protection zones along urban and regional traffic lines.

Heavy Metals in the Leaves of Tree Species Paulownia Elongata S.Y.Hu in the Region of the City of Belgrade

ABSTRACTBased on the analysis of the heavy metal content (Zn, Fe, Pb, Cu, Ni, Cr, Mn, Cd, As, Hg) in leaves of the trees growing in the urban part of the city of Belgrade, wider city area and rural area it may be noted that the content of Fe, Pb, Ni, Cr and Cd increases going from rural to urban area. The obtained results may be related to the increased air pollution in urban and suburban areas where some of these heavy metals appear as a direct consequence of fuel combustion.The level of tolerance of the species Paulownia elongata S.Y.HU towards air pollution represents the basis for its development and survival in urban conditions as well as setting up of tree alleys and forming wind protection zones along main traffic lines.

Heavy metal distribution between contaminated soil and Paulownia tomentosa, in a pilot-scale assisted phytoremediation study: Influence of different complexing agents

The distribution of Cd, Cu, Pb and Zn between a contaminated soil and the tree species Paulownia tomentosa was investigated in a pilot-scale assisted phytoremediation study. The influence of the addition of EDTA, tartrate and glutamate at 1, 5 and 10mM concentrations on metal accumulation by the plant and on metal mobilization in soil was evaluated. Root/shoot metal concentration ratios were in the range of 3–5 for Zn, 7–17 for Cu, 9–18 for Cd and 11–39 for Pb, depending on the type and concentration of complexing agent. A significant enhancement of metal uptake in response to complexing agent application was mainly obtained in roots for Pb (i.e. 359mgkg−1 for EDTA 10mM and 128mgkg−1 for the control), Cu (i.e. 594mgkg−1 for glutamate 10mM and 146mgkg−1 for the control) and, with the exception of glutamate, also for Zn (i.e. 670mgkg−1 for tartrate 10mM and 237mgkg−1 for the control). Despite its higher metal mobilization capacity, EDTA produced a metal accumulation in plants quite similar to those obtained with tartrate and glutamate. Consequently the concentration gradient between soil pore water and plant tissues does not seem to be the predominant mechanism for metal accumulation in Paulownia tomentosa and a role of the plant should be invoked in the selection of the chemical species taken up. Metal bioavailability in soil at the end of the experiment was higher in the trials treated with EDTA than in those treated with tartrate and glutamate, the latter not being significantly different from the control. These findings indicated the persistence of a leaching risk associated to the use of this chelator, while an increase of the environmental impact is not expected when glutamate and tartrate are applied.

Fire in a Thermic Oak-Pine Forest in Linville Gorge Wilderness Area, North Carolina: Importance of the Shrub Layer to Ecosystem Response

ABSTRACT Dedication The authors of this article dedicate this paper to the memory of Dr. Bruce Haines, University of Georgia, in honor of his outstanding accomplishments in the field of ecosystem ecology. A good scientist, a good mentor, and a good friend. In the fall of 2000, a ground fire burned much of the Linville Gorge Wilderness Area, North Carolina, providing an opportunity to study the effects of fire on an oak-pine forest that had not been burned in 50 years. There was no immediate overstory mortality in our study plots. Most aboveground stems of Kalmia latifolia were killed back, but most survived and subsequently re-sprouted. Fire reduced surface organic horizons by nearly 50%, and increased light penetration ∼15%, resulting in greater soil temperature extremes. Fire increased species richness in the herb layer and allowed establishment of pine seedlings and also the exotic invasive tree species Paulownia tomentosa. Rates of soil respiration and litter decomposition were significantly lower in ...

Carbonic anhydrase activity and photosynthetic rate in the tree species Paulownia tomentosa Steud. Effect of dimethylsulfoxide treatment and zinc accumulation in leaves

The enzyme carbonic anhydrase (CA) (EC 4.2.1.1) catalyzes the reversible conversion of CO2 to HCO3- and has been shown to be involved in photosynthesis. The enzyme has been shown in animals, plants, eubacteria and viruses, but similar reports on the evidence for CA activity in tree plants does not be appear to be available. In the preliminary analyses of the work, the CA activity in leaf extracts from the tree species Paulownia tomentosa Steud. (introduced in Bulgaria) is described. A connection between CA activity and the rate of photosynthetic CO2 fixation is shown. In the second portion of the work, the effect of 10(-4) mol/L and 10(-2) mol/L dimethylsulfoxide (DMSO) on the zinc accumulation in leaves is demonstrated. It is suggested that CA activity is an indicator of the level of physiologically active zinc in leaves of P. tomentosa Steud. A connection between the process of zinc accumulation in leaves and the activity of the enzymes CA and glycolate oxidase (GO) (EC 1.1.3.1) is established.

Callus induction from leaves of differentpaulownia species and its plantlet regeneration

The experiment was carried out on five different species ofPaulownia for callus induction from leaves. MS medium was adopted as basic medium, and from different combinations of NAA and BA the suitable media were determined for callus induction, bud differentiation, and root differentiation of five different species. MS+0.5NAA+4BA, MS+0.3NAA+2BA, MS+0.5NAA+4BA, MS+0.3NAA+6BA, and MS+0.3NAA+8BA were suitable media of callus inductions of leaves, respectively, forPaulownia tomentosa, Paulownia australis, Paulownia fortunei, Paulownia elongata andP. tmentosa x P. fortunei, and MS+0.3NAA+12BA, MS+0.3NAA+12BA, MS+0.5NAA+12BA, MS+0.5NAA+12BA, and MS+0.7NAA+12BA were suitable media for bud differentiation from leaf callus respectively for above five species. The rooting media was determined as 2MS+0.1NAA, 1/2MS+0.1NAA, 1/2MS, 1/2MS+0.3NAA, and 1/2MS+0.5NAA. These results provide reference data for breeding new fine varieties with different kinds ofPaulownia protoplasts fusions.

Development of the gas production technique to assay for anti-nutritive compounds in temperate tree fodders with polyphenol adsorbents using inoculum based on fresh cattle faeces

The polyphenol concentration in various tree fodders has been assayed by the gas production technique using rumen fluid inoculum either by fermentation of whole samples +/- a polyphenol adsorbent (Khazaal et al., 1994) or simply by the reduction of gas production caused by acetone extracts of the fodders (Wood and Plumb, 1995). Successful replacement of rumen fluid as a source of anaerobic bacteria by faeces from ruminant animals has been reported both for two-stage Tilley and Terry dry-matter digestibility (DMD) (El Shaer et al., 1987) and for the gas production technique (Davies, 1991). The use of faeces based inoculum +/- polyphenol adsorbents was therefore tested and optimized for fallen paulownia and poplar leaves using the gas production technique (the trees were commercial hybrids of Paulownia and Populus species respectively). A series of trials was carried out to: develop the use of preliminary incubation of the faeces inoculum; optimize the adsorbent type, molecular weight (MW) and quantity; optimize the faeces concentration in the inoculum and the use of glucose as a pre-incubation stimulant; and evaluate the use of differences in Tl /2 for gas production and end DMD +/- adsorbent to assess the effect of anti-nutritive compounds (ANCs) on the relative rate and extent of fermentation.All trials were carried out using 100 ml plastic vaccine flexibottles as containers maintained at 39°C in water baths. Gas was manually extracted with disposable syringes, generally at 3, 6, 9,12,15,18, 21, 24, 30, 36, 42, 48, 60, 72 h and bottles were well shaken at these times.

Relationship between witches’ broom protein and dynamic of some amino acids inPaulownia tree leaves

This paper dealt with the SDS polyacrymide gel electrophoresis of proteins and analysis of the amino acids in the diseased and healthy leaves with the same strain respectively, which were at the same side and height, ofPaulownia catalpifolia, P. elongata, P. albiphloea andP. kauakamii respectively. The results indicated that the leaves of 4 species ofPaulownia trees with witches’ broom had one protein band, of which molecular weight was 12 kD, which did not appear in the healthy leaves free of phytoplasmas. Moreover, the protein quantity in the affected leaves was more than that in the healthy leaves free of phytoplasmas; At the same time, there was significant difference on the amino acids between the healthy and diseased leaves ofP. catalpifolia andP. kawakamii. The amount of cystine in the affected leaves was higher than that in the healthy leaves, but the change of amount of phenylalanine in the affected and healthy leaves was contrary. These changes of proteins and amino acids in the leaves might be related to the witches’ broom of theParlounia trees.

High frequency adventitious shoot regeneration from excised leaves ofPaulownia spp. cultured in vitro

High frequency, direct regeneration of shoots was induced in leaf cultures ofPaulownia tomentosa, P. fortunei x P. tomentosa andP. kawakamii. The optimum culture medium for the leaf explants derived from shoot cultures was Murashige-Skoog (MS) medium supplemented with 10 μM indole-3-acetic acid and 50 μM benzyladenine. Up to 40 shoots were obtained over a 4 month culture period from each leaf explant. Rooting occurred spontaneously in the shoots that were about 1 cm tall when subcultured on phytohormone-free MS medium. The plantlets could be transplanted successfully. Some of the transplantedP. tomentosa plantlets flowered in the greenhouse one year after transplanting. The protocol is suitable not only for rapid multiplication of the various species ofPaulownia, but also for analytical studies associated with adventitious shoot regeneration.

Molecular evidence for the hybrid origin of Paulownia Taiwaniana based on RAPD markers and RFLP of chloroplast DNA

Genomic DNA of Paulownia fortunei, P. kawakamii and P. taiwaniana were amplified with 10-base primers of arbitrary sequences using the polymerase chain reaction (PCR). A total of 351 DNA fragments were amplified from 23 primers and of these 265 fragments (75.5%) were polymorphic. Almost all of the PCR-amplified products of P. taiwaniana were shared by either P. fortunei or P. kawakamii, or both, and the number of polymorphic fragments shared by P. taiwaniana and P. fortunei was about equivalent to those shared by P. taiwaniana and P. kawakamii. Restriction fragments of chloroplast DNA (cpDNA) purified from Paulownia species and from reciprocal crosses between P. fortunei and P. kawakamii were analyzed. Restriction enzyme SalI-digested cpDNA showed an identical pattern in both P. kawakamii and P. taiwaniana. These results further support the hypothesis that P. taiwaniana is the natural hybrid between P. fortunei and P. kawakamii and that the maternal parent of P. taiwaniana is P. kawakamii.

Scanning electron microscopy of the seed coat in the genus Paulownia (Scrophulariaceae)

A comparative study of the microscopic structures of external features of mature seeds of eight Paulownia species is presented. The external surface of the seed is made up of reticulate, apparently translucent cells, which laterally extend into wing-like structures. The laterally symmetrical wings are unequally extended in the micropylar and chalazal regions. The seed-coat ornamentation has a dorsiventral nature. Some special features of seed-coat morphology amongst the eight Paulownia species are discussed.