Adsorption/desorption characteristics and enrichment of quercetin, luteolin and apigenin from Flos populi using macroporous resin

Abstract In this study, the adsorption/desorption characteristics of quercetin, luteolin and apigenin from Flos populi extract (Populus tomentosa Carrière, Salicaceae) on twelve macroporous resins (NKA-9, HPD-600, HPD-826, HPD-750, HPD-400, DM-130, AB-8, SP-825, X-5, D-101, HPD-100, HPD-200) were evaluated. Both high adsorption and desorption capacities of quercetin, luteolin and apigenin from Flos populi extract on SP-825 resin indicated that SP-825 resin was appropriate and its data were well fitted to the Langmuir and Freundlich isotherms. To get the optimal separation process, the influences of factors such as flow rates, loading sample volumes, concentrations of desorption solution were further investigated. Column packed with SP-825 resin was used to perform dynamic adsorption and desorption experiments. After one round of treatment, the contents of quercetin, luteolin and apigenin in the final products were 3.75-fold, 3.67-fold and 3.54-fold increased with recovery yields of 87.25, 85.19 and 82.22%, respectively. The results showed that the preparative enrichment of quercetin, luteolin and apigenin was available via adsorption and desorption on SP-825 resin. This method is a promising basis for the large-scale preparation of quercetin, luteolin and apigenin from Flos populi.

Antimicrobial and antibiofilm activities of phenolic compounds extracted from Populus nigra and Populus alba buds (Algeria)

The interest of this work is the discovery of new antimicrobial agents of plant origin to inhibit the formation of microbial biofilms. The present research was conducted to identify and quantify the phenolic compounds extracted from Populus nigra and Populus alba buds harvested in the area of Tizi-Ouzou (Algeria), and to evaluate their antimicrobial and antibiofilm activity. High performance liquid chromatography (HPLC) was performed to identify the phenolic compounds in the ethyl acetate fraction of P. nigra and the methanolic extracts of P. nigra and P. alba. The antimicrobial activity of the crude extracts and the fractions of these two species was tested against 11 microorganisms, using the disk diffusion method, while the antibiofilm effect of certain extracts was carried out in a 96-well microplate and on a biomaterial (catheter). HPLC analysis revealed the presence of 10 bioactive compounds. The main phenolic compounds identified in the three extracts were p-coumaric acid, ellagic acid, and Kaempferol. This study was able to demonstrate that the extracts of P. nigra and P. alba buds have interesting antimicrobial properties, with diameters ranging from 6.6 to 21.3 mm. In addition, extracts of P. nigra exhibited antibiofilm effects greater than 70%. Our results provide evidence for the antimicrobial and antibiofilm potential of bud extracts from both poplar species. Thus, these results will pave the way for further research on these two plants.

Pretreatment of Populus tomentiglandulosa protects hippocampal CA1 pyramidal neurons from ischemia-reperfusion injury in gerbils via increasing SODs expressions and maintaining BDNF and IGF-I expressions / 中国天然药物

To examine the effects of Populus tomentiglandulosa (PT) extract on the expressions of antioxidant enzymes and neurotrophic factors in the cornu ammonis 1 (CA1) region of the hippocampus at 5 min after inducing transient global cerebral ischemia (TGCI) in gerbils, TGCI was induced by occlusion of common carotid arteries for 5 min. Before ischemic surgery, 200 mg·kg PT extract was orally administrated once daily for 7 d. We performed neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B staining. Furthermore, we determined in situ production of superoxide anion radical, expression levels of SOD1 and SOD2 as antioxidant enzymes and brain-derived neurotrophic factor (BDNF) and insulin-like growth factor I (IGF-I) as neurotrophic factors. Pretreatment with 200 mg·kg PT extract prevented neuronal death (loss). Furthermore, pretreatment with 200 mg·kg PT extract significantly inhibited the production of superoxide anion radical, increased expressions of SODs and maintained expressions of BDNF and IGF-I. Such increased expressions of SODs were maintained in the neurons after IRI. In summary, pretreated PT extract can significantly increase levels of SODs and protect the neurons against TGCI, suggesting that PT can be a useful natural agent to protect against TGCI.

Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions

ABSTRACT Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana × P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1-T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40 mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62 mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.

Pre-treated Populus tomentiglandulosa extract inhibits neuronal loss and alleviates gliosis in the gerbil hippocampal CA1 area induced by transient global cerebral ischemia / 대한해부학회지

The genus Populus (poplar) belonging to the Salicaceae family has been used in traditional medicine, and its several species show various pharmacological properties including antioxidant and anti-inflammatory effects. No study regarding protective effects of Populus species against cerebral ischemia has been reported. Therefore, in the present study, we examined neuroprotective effects of ethanol extract from Populus tomentiglandulosa (Korea poplar) in the hippocampal cornu ammonis (CA1) area of gerbils subjected to 5 minutes of transient global cerebral ischemia. Pretreatment with 200 mg/kg of P. tomentiglandulosa extract effectively protected CA1 pyramidal neurons from transient global cerebral ischemia. In addition, glial fibrillary acidic protein immunoreactive astrocytes and ionized calcium binding adapter molecule 1 immunoreactive microglia were significantly diminished in the ischemic CA1 area by pretreatment with 200 mg/kg of P. tomentiglandulosa extract. Briefly, our results indicate that pretreatment with P. tomentiglandulosa extract protects neurons from transient cerebral ischemic injury and diminish cerebral ischemia-induced reactive gliosis in ischemic CA1 area. Based on these results, we suggest that P. tomentiglandulosa can be used as a potential candidate for prevention of ischemic injury.

Efficiency of treatments for controlling Trichoderma spp during spawning in cultivation of lignicolous mushrooms

Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 ºC), immersion in hot water (60 and 80 ºC), and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (10(5) conidia/mL) and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 ºC for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species.

Vegetation dynamics on waste landfills in the Seoul metropolitan area

The goal of this study was to survey the natural vegetation on waste landfills and suggest a restoration plan. In the study, I identified 63 families, 275 species, and 34 varieties of aboveground vascular flora. Robinia pseudo-acacia was the dominant tree, with a basal area density of 1.51-3/ha, followed in decreasing order by Salix koreensis and Populus sieboldii. TWINSPAN resulted in the classification of 6 communities. The result of Detrended Canonical Correspondence Analysis [DCCA] of 24 environmental variables and vegetation data was that the presence of artificial turf, human disturbance, landfill age, presence of periodic management and soil Na levels were correlated with the first axis. Soil chemical analyses showed that total nitrogen was greater at control sites than in landfills, but levels of K, Na, Ca, Mg, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were greater in landfills than at control sites. Current planning by central and local governments calls for converting waste landfills into ecological parks or golf courses. In the initial stages of a landfill closure, a landfill restoration plan must be made to select soil for capping the landfill and to plan for future facilities. If vegetation is present near the landfill to provide a propagule source, the recommended course of action is to allow for natural restoration to occur through propagule dispersal and successional processes. However, if the landfill stands as a secluded island without a nearby propagule source, artificial restoration methods are suggested

Functional divergence of betaine aldehyde dehydrogenase genes in Populus euphratica / 生物工程学报

Plant betaine aldehyde dehydrogenase (BADH) is a physiologically important enzyme in response to salt or drought stress. In this study, two BADH genes (PeBADH1 and PeBADH2) were cloned from Populus euphratica. Both PeBADH1 and PeBADH2 genes encode the proteins of 503 amino acid residues, with a calculated molecular mass of 54.93 kDa and 54.90 kDa, respectively. Reverse transcription PCR showed the divergence of expression pattern between the PeBADH1 and PeBADH2 genes in P. euphratica. The recombinant PeBADH1 and PeBADH2 proteins were overexpressed in E. coli, and purified by Ni-affinity chromatography. The PeBADH2 protein had 1.5-fold higher enzymatic activity towards the substrate aldehyde than PeBADH1 protein. The PeBADH1 protein revealed higher thermal stability than PeBADH2 protein. These results indicated obvious functional divergence between the PeBADH1 and PeBADH2 genes.

Chemical constituents contained in Populus tomentosa / 中国中药杂志

<p><b>OBJECTIVE</b>To separate and identify chemical constituents from stem barks of male plants of Populus tomentosa.</p><p><b>METHOD</b>Fresh stem barks of P. tomentosa were extracted with methanol to obtain extracts which were suspended in water and blended successively with petroleum ether, ethyl acetate and n-butanol. Various chromatographic techniques were used to separate and purify the constituents extracted with ethyl acetate and n-butanol fractions. Their structures were identified on the basis of their physicochemical properties and spectral data.</p><p><b>RESULT</b>Twelve compounds were separated with ethyl acetate and n-butanol fractions and identified as benzoic acid (1), daucosterol (2), tremuloidin (3), rhamnocitrin (4), sakuranetin (5), 7-O-methylaromadendrin (6), isograndidentatin A (7), siebolside B (8), sakuranin (9), micranthoside (10), alpha-D-glucopyranose (11), and sucrose (12).</p><p><b>CONCLUSION</b>Compounds 4-12 were separated from this plant for the first time. Of them, compound 10 was separated from this plant genus for the first time.</p>

Phytoremediation potential of Populus alba and Moms alba for cadmium, chromuim and nickel absorption from polluted soil

Metal pollution has become one of the most serious environmental problems resulting from human activity. Phytoremediation utilizes plants to uptake contaminants and can potentially be used to remediate metal-contaminated sites. The present study investigates heavy metal uptake [Cd, Cr, and Ni] from soil by different organs of Populus alba and Moms alba. For this purpose, Cd [40, 80, and 160 mg/kg], Cr [60, 120, and 240 mg/kg] and Ni [120, 240, and 480 mg/kg] were added to the soil in pot experiments over the course of a growing season in open air. The total concentration of these metals was measured in the roots, stems, green leaves, fallen leaves, and the corresponding soil. Our results show that the highest accumulation of all studied metals was found in the leaves. Furthermore, the fallen leaves had higher concentrations of Cd and Cr in P. alba and Cr and Ni in M. alba when compared to the green leaves. In the two species, Cd and Ni did not transport from the leaves to the roots and stems, or vice versa, in the fall season, but Cr was transported from the roots and stems to the leaves in the 240 and 480 mg/kg treatments.In addition, the determination of a bioconcentration factor and a translocation factor showed that P. alba and M. alba were suitable for phytoextraction of Cd and Ni in all treatments respectively; however, none of the plants was suitable for phytostabilization

Phytochemical study and evaluation of the anti-inflammatory activity of some medicinal plants growing in Egypt

The anti-inflammatory activity of different extracts of five plants abundantly growing in Egypt, namely Ipomoea palmate Forsk. [Convolvulaceae], Alstonia scholaris R.Br. [Apocynaceae], Salix subserrata Willd., Salix tetrasperma Roxb, and Populus nigra Linn. [Salicaceae] has been studied. Phytochemical study on selected bioactive extracts was carried out as well as their possible mechanism of action. The results revealed a significant anti-inflammatory activity of the extracts under investigation to different degrees. A chromatographic study of the bioactive lipoidal extracts of A. scholaris and I. palmate was carried out and the results revealed the presence of unsaturated fatty acids [linoleic and linoleic]. Beta-sitosterol and campesterol were present in A. scholaris and I. palmate, respectively. Chromatographic and spectral investigation of the flavonoids in the bioactive aqueous extract of I. palmate revealed the presence of luteolin, quercetin 7-glycosie and apigenin. The anti-inflammatory activity may be due to the presence of these phytochemical constituents

Oxidation of oxymyoglobin by poplar plastocyanins a and b.

Oxidation of oxymyoglobin [MbO2 (Fe2+)] by isoplastocyanins a (PCa) and b (PCb) was experimentally investigated and the corresponding redox reaction was modeled using the physicochemical parameters of the isoforms to study the effect of the dimorphism. The kinetic curve of oxidation of MbO2 (Fe2+) by oxidized PCa [PCa(Cu2+)] and PCb [PCb(Cu2+)] and the pH-dependence of the rate constant k1 were determined. In the range of pH 4.8-9.0, PCb reacts with higher k1, compared with PCa. For example, at pH 7.0, k1(PCb) = 4 × 102 M-1s-1, whereas k1(PCa) = 2 × 102 M-1s-1. The observed values of ΔE0 for the reaction pairs Mb-PCa and Mb-PCb were -304 mV and -319 mV, respectively. The effect of the ionic strength (µ) on the rate of the electron transfer was also studied. It was found that: (i) the net charge Z1 of PCa and PCb fully corresponds to that calculated by their primary structures and Z2 of Mb corresponds to that calculated by its titration curve; (ii) the ln k as function of √¯µ was similar for both PCa and PCb; (iii) the curve of the reaction PCb Mb (pH 7.0) was shifted towards higher values of k, in agreement with the larger net negative charge of PCb; and (iv) the character of the electrostatic interactions remained unchanged by a replacement of PCa by PCb and by the change of pH from 7.0 to 4.8.

Behavior and preservation of an in vitro collection of European aspen in Spain

An in vitro collection has been Established with selected European aspen from Palencia province (Spain). Currently, this collection includes 32 high quality clones, selected for their good bearing and healthy state. Most of them belong to different discrete local populations. Populus tremula L. was propagated in proliferation Aspen Culture Medium; they required subculture every 3 months. The purpose of this study was, therefore, to select a medium which allows the maintenance of 32 clones for a period longer than 3 months without subculture and to observe the behavior of those clones in 15 different culture medium compositions. Seven nodal cutting stem explants from each clone were cultured in parallel in the different media. One and three months after setting on the stem explants, the number and the size of shoots, the root size, the presence or absence of callus and the survival, were evaluated. The survival was monthly recorded during 8 months. Taking into account the explant development, four media were proposed for collection preservation. One of them, Ga, with a reduction of salts, sucrose, 6-benzoaminopurine, omitting adenine sulphate and 1-naphthalene acetic acid, is the most economical. Behavior observations of the 32 clones in the 15 medium compositions showed the influence of the genotype of the clones.

Cerrena unicolor (Bull.) Murr.(Basidiomycota) aislado de micangio de Tremex fuscicornis Fabr. (Hymenoptero Siricidae) asociado a decaimiento y pudrición del Alamo (Populus sp.) en Chile / Cerrena unicolor(Bull.)Murr.(Basidiomycota) isolated from mycangia of Tremex fuscicornis Fabr. (Hymenoptera Siricidae) associated to poplar decline (Populus sp.) in Chile)

Entre septiembre a diciembre del 2004 el Instituto Forestal y el Servicio Agrícola y Ganadero, en investigaciones conjuntas de estrategias de control biológico para Tremex fuscicornis Fabr. (Hym. Siricidae), se profundizó en el conocimiento de la asociación simbiótica que presenta esta avispa xilófaga con un hongo. T. fuscicornis, es una avispa taladradora del álamo que presenta en sus glándulas micangiales el micelio y esporas de un hongo asociado, el cual inyectado al árbol en el momento de la oviposición, causa su posterior decaimiento y biodegradación. Desde hembras adultas se obtuvieron los micangios que contenían micelio y artrosporas del hongo, estos fueron macerados y posteriormente sembrados en agar papa dextrosa, desarrollándose colonias fúngicas que formaron artrosporas. El micelio de estas colonias fue inoculado en varios tipos de sustratos vegetales esterillizados, en especial en trozas de álamo, donde se desarrollaron basidiocarpos, los que taxonómicamente correspondieron a Cerrena unicolor (Bull.) Murr., primer reporte para Chile de este basidiomicete.

Since september to december 2004,Instituto Forestal and Servicio Agrícola y Ganadero, while investigating together the strategies for the biological control of Tremex fuscicornis Fabr. (Hym.Siricidae), acquired thorough knowledge about the symbiotic association existing between this xylophagus wasp with a fungus. T. fuscicornis is a horntail wasp attacking poplar trees and which has in its mycangial glands the mycelium and spores of an associated fungus that once injected in the tree at the oviposition stage, causes its further decayand rottenness. Mycangia containing mycelium and arthrospores of this fungi were obtained from adult females. They were macerated and then cultivated inpotato dextrose agar (PDA) what resulted in fungal colonies that further formed arthrospores. The myceliumof these colonies was inoculated into different kinds of sterilized vegetal substrates, mainly in pieces of poplartrees, where basidiocarpes were developed, taxonomically corresponding to Cerrena unicolor (Bull.) Murr., thisbeing the first report on this basidiomycete in Chile.

Trace element biomonitoring by leaves of Populus nigra L. from Western Anatolia, Turkey.

The West Anatolian Region is one of the most important areas for industrialization, population density and traffic in Turkey. Therefore, the leaves of Populus nigra L. (Salicaceae), which are used as biomonitor to investigate the levels of the trace elements Cd, Pb, Fe, Zn and Cu, were sampled at 30 locations having different pollution levels in the region. The concentrations of elements were determined by atomic absorption spectrometry. The samples were collected at both reference and contaminated locations where iron was found as the priority element. The strong association between a gradient of contamination and concentration in all samples tested indicates that they are reflecting well the environmental changes, and that they appear as appropriate biological indicators of heavy metal contamination.

Isolation and characterization of a DRE-binding transcription factor from Yinxin poplar (Populus alba x P. alba var. pyramidalis) / 生物工程学报

Dehydration-Responsive Element Binding ( DREB) transcription factors, specifically binding with dehydration reponsive element (DRE), activate a variety of stress-responsive genes in plants under abiotic stresses (dehydration, high salt and low temperature). Using PCR and homologous EST search, we isolated a DREB-like gene from Yinxin poplar (Populus alba x P. alba var. pyramidalis) named PaDREB2. Yeast One-hybrid experiment demonstrated that PaDREB2 protein could function as a DREB transcription factor activating target gene expression by specifically binding to DRE cis-element. To study the expression pattern of PaDREB2, RT-PCR was carried out. And the results showed that PaDREB2 is induced by low temperature, drought and high salt.

Sequence analysis of bacterial transposon in NHX gene of Populus euphratica / 生物工程学报

The United Nations Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed. The gene NHX (Na+/H+ exchanger) encodes functional protein that catalyzes the countertransport of Na+ and H+ across membranes and may play an important role in plant salt tolerance. To clone the NHX from the wild plant Populus euphratica collected in Tarim basin and Xinjiang Wujiaqu district into a T-vector, designed primer was used to amplify 1kb NHX cDNA fragment with RT-PCR. Total RNA was extracted from Populus euphratica tissue (plant tissue was collected from Tarim basin and Xinjiang Wujiaqu district and stored in liquid nitrogen) according to the Plant RNA Mini Kits of Omega. First cDNAs were synthesized from 1 microg total RNA of Populus euphratica seedling. A pair of primers were used to perform RT-PCR. The amplified DNA fragment was purified and cloned into pMD18-T vector. However, 1kb and 2.3kb fragment were obtained from Tarim basin and Xinjiang Wujiaqu district and named as PtNHX and PwNHX, respectively. Sequence analysis reveals that the cloned PtNHX fragment of Populus euphratica contains partial NHX coding region with 98%, 86%, 84% and 80% identity comparing with Atriplex gemelini, Suaeda maritima, Arabidopsis thaliana and Oryza sativa, respectively. This analysis suggests that NHX gene would be highly conserved in terms of evolution in plant; and it also suggests that the NHX gene of Populus euphratica also would have the similarity with that of Arabidopsis. It may be of great importance in improvement of the plant salt tolerance and breed of crop. At the same time, sequence analysis shows that PwNHX gene includes a coding region about 1350bp with 99% identity comparing with transposon Tn10 IS10-left transposase of Shigella flexneri. On the one hand, the NHX gene may lose its function because it was inserted a fragment in coding region. On the other hand, its product may play a important role in salt tolerance. Populus grow in saline soil. It speculates that it may have other salt tolerance mechanism in Populus. The transposon can be used as transposon tagging to clone other genes and it will help us to understand farther the salt tolerance mechanism.

Analysis of salt resistance on the poplar transferred with salt tolerance gene / 生物工程学报

Poplar(Pupulus x Xiao zhannica, cv. "balizhuang-yang") transferred with mtl-D gene was used as an experimental material. Through tissue culture, aquaculture and pot culture transgenic poplars are tested with variant Nacl salt gradient. In it transgenic poplar raises its initial days for differentiation, differentiation rate, bud intensity, bud height and growth potential than control plant. At the same time, the transgenic poplar has higher rooting rate and more top roots, side roots and higher root length than control under the same salt stress. The result shows that the transgenic poplar has better tolerance ability than control plant in the salt 4@1000 contensity mediums.

Aerobiological Study for Airborne Plooern and Mold in Kuri-shi, Kyunggi-Do / 소아알레르기및호흡기학회지

In a large number of a1lergic cases, inhalant allergens, particularly airborne pollens and mo1ds am important causative, triggering agents in respiratory, even in skinanergy. It is essential for diagnosis and treatment of airborne allergy to survey the airborne pollen and mo1d in the patient's living area. Rotorod samp1er was installed on the well-ventilated rooftop of Hanyang Kuri Hospital in Kuri-shi, Kyunggi-do as the vicinity of Seoul. Airborne allergens were collected from October 1, 1995 to September 30, 1996 daily and were stained with Calberla`s fuchsin and were identified, counted under the light microscope (400Xfor pollen, 1000Xfor mold). The data were compared with the local daily weather report. The airborne pollen was found from 12th February to 22nd December. The maximal period for pollen collection was 7th-25th May (Maximal count:492 grains/ August. There were Alnus, Betula, Pinus, Quercus, Acer, Ulmus, PopuluS, Cupressaceae, Ginkgo, Corylus, Salk in the tree season from middle of February to middle of July. The grass season ranged from middle of March to end of November. There were Artemisia, Ambrosia, HumuluS, Chenopodium-Amaranthus, rumex, Plantago, Trifoium, Humulus, Chrysanthemum, Cyperus in the weed season ranged from middle of July to end of December. Airborne molds were collected all through the year except JanuaIgamma but, counted maximally from the middle of June to end l August. There were CladosPorium, Alternaria, ascospore of Leptospheria, Periconia, Myxomycete, Drechs1era, Rust urediniospores, Basidiospore, ToruIa, Xylariaceae, IOidimn, Nigrospom, Stempi1y1ium, Amphispheda, Fusarium, Aspergil1us. In Korea, there are great number of the allergic patients, but we have had a little records and data about study of relationship between the allergic diseases and airborne environmental allergens. we will reported those results completely in future.

Comparative Genetic Characterization of Plasmids of Agrobacterium Species Isolated in Korea / 영남의대학술지

The soil bacterium Agrobacterium tumefaciens is a plant pathogen that causes crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor–inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; A₁₋₃, Populus monilifera; W₁₋₆, Populus tomentiglandlosa; P₁₋₃ and Rosa species; R₁) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains (W₂, W₃, W₆, P₁, P₃ and A₂). The test for crown gall tumor formation was resulted only in ATCC15955 and KW2 strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC15955 and pTiKW₂ observed by EcoR I ; 25&27, Hind III ; 23&21, BamH I ; each 20 and Hpa I ; 12&27. And sizes of pTiATCC15955 and and pTiKW₂ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue (W₁₋₆ and P₁₋₃) and these strains confirmed as octopine type.