Pyrogalloloestrogens: enzymic methylation of pyrogalloloestrogens and interaction of pyrogalloloestrogens with the enzymic methylation of catecholamines in rat liver in vitro.

During incubation of 2,4-dihydroxyoestrone with the 105000 X g supernatant of rat liver in the presence of S-adenosyl-[Me-14C]methionine, the formation of radioactive mono- as well as dimethyl ether derivatives was demonstrated. The products were identified as: 2,4-dihydroxyoestrone 2-methyl ether, 2,4-dihydroxyoestrone 3-methyl ether, 2,4-dihydroxyoestrone 4-methyl ether, 2,4-dihydroxyoestrone 2,3-dimethyl ether, 2,4-dihydroxyoestrone 2,4-dimethyl ether and 2,4-dihydroxyoestrone 3,4-dimethyl ether. The monomethyl ethers were the main products; within this group the 3-methyl ether of 2,4-dihydroxyoestrone was the main metabolite. Among the dimethyl ether derivatives, the 2,4-dihydroxyoestrone 2,3-dimethyl ether represented the quantitatively most important product. When 2,4-dihydroxyoestrone 2-methyl ether was incubated under the same conditions, 2,4-dihydroxyoestrone 2,3- as well as 2,4-dimethyl ether was formed. The 2,3-dimethyl ether was again the main metabolite. The incubation of 2,4-dihydroxyoestrone 4-methyl ether yielded the 2,4- and 3,4-dimethyl ethers, the first being the main product. In contrast, the 3-methyl ether of 2,4-dihydroxyoestrone was not further methylated by the catechol methyltransferase preparation. In further experiments, the effect of the pyrogalloloestrogen and its monomethyl ether derivatives on the enzymatic methylation of catecholamines was investigated. It was demonstrated that the methylation of adrenalin and dopamine was competitively inhibited by 2,4-dihydroxyoestrone and the 2,4-dihydroxyoestrone monomethyl ethers. Only a weak inhibitory effect was observed with the 3- and 4-monomenthyl ethers (Ki values 200 and 160muM). The unsubstituted pyrogalloloestrogen produced a marked inhibition (Ki value 50muM), but the strongest inhibition was found with the 2-monomethyl ether of 2,4-dihydroxyoestrone (Ki value 14muM). The extent of inhibition caused by the addition of the 2-monomethyl ether of 2,4-dihydroxyoestrone was thereby in the same range as the inhibition caused by pyrogallol and the catecholoestrogens.     

Effects of 2,4-D and its metabolite 2,4-dichlorophenol on antioxidant enzymes and level of glutathione in human erythrocytes

The effects of in vitro exposure of human erythrocytes to different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and its metabolite 2,4-dichlorophenol (2,4-DCP) were studied. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of reduced glutathione (GSH) were determined. The activity of erythrocyte superoxide dismutase SOD decreased with increasing dose of 2,4-D and 2,4-DCP, while glutathione peroxidase activity increased. 2,4-D (500 ppm) decreased the level of reduced glutathione in erythrocytes by 18% and 2,4-DCP (250 ppm) by 32%, respectively, in comparison with the controls. These results lead to the conclusion that in vitro administration of herbicide-2,4-D and its metabolite 2,4-DCP causes a decrease in the level of reduced glutathione in erythrocytes and significant changes in antioxidant enzyme activities. Comparison of the toxicity of 2,4-D and 2,4-DCP revealed that the most prominent changes occurred in human erythrocytes incubated with 2,4-DCP.     

A comparison of 2,4-dichlorophenoxyacetic Acid metabolism in cultured soybean cells and in embryogenic carrot cells

The removal or reduction in concentration of auxin is often a successful method for obtaining morphogenesis in cell cultures of higher plants, such as carrot, but not for soybean. For this reason, the metabolism of one auxin, 2,4-dichlorophenoxyacetic acid (2,4-D), was compared in both carrot and soybean cells. Whereas soybean cells conjugated a high percentage of their 2,4-D to amino acids, carrot cells contained primarily free 2,4-D. Moreover, after long-term exposure to 2,4-D, carrot cells released much more 2,4-D upon transfer to 2,4-D-free (embryogenic) medium than did soybean cells. It appears that the retention of 2,4-D by soybean cells might interfere with subsequent morphogenesis. Because no impairment of 2,4-D efflux was found with short-term exposure to radiolabeled 2,4-D, it was concluded that 2,4-D retention in soybean cells might be due to a time-dependent, metabolic process. The conjugation of 2,4-D to amino acids was shown to be one such time-dependent process. Additionally, the release of 2,4-D from the cells was shown to be due primarily to a loss of free 2,4-D and not 2,4-D-amino acid conjugates. It seems that the greater retention of 2,4-D by soybean cells upon transfer to 2,4-D-free medium is due to greater formation of 2,4-D-amino acid conjugates.     

Studies on plant growth-regulating substances XXVII. The growth-regulating activity and metabolism of 2,4-dichlorophenoxyethylamine and related compounds in higher plants

2-(2,4-Dichlorophenoxy)ethylamine (2,4-D ethylamine) was converted to 2,4-dichlorophenoxyacetaldehyde (2,4-D acetaldehyde) by extracts of pea cotyledons. The 2,4-D acetaldehyde was further converted to 2,4-dichloro-phenol and 2,4-dichlorophenoxyacetic acid (2,4-D). Under the same conditions, 2-(2,6-dichlorophenoxy)ethylamine was converted to 2,6-dichloro-phenoxyacetaldehyde and 2,6-dichlorophenol, although at a relatively slow rate. In pea stem segments and wheat coleoptiles the main products of 2,4-D ethylamine metabolism were 2,4-dichlorophenol, 2,4-D acetaldehyde and 2,4-D. In comparison with the wheat coleoptiles, larger amounts of these products were found in the pea stem segments. Metabolism of 2,4-D acetaldehyde gave 2-(2,4-dichlorophenoxy)ethanol (2,4-D ethanol) and 2,4-D in both pea and wheat tissues. Pretreatment with the amine oxidase inhibitor, 2-hydroxyethylhydrazine (HEH) completely prevented the extension of pea stem segments and substantially prevented the extension of wheat coleoptiles on subsequent treatment with 2,4-D ethylamine. No such protection was found against 2,4-D acetaldehyde or 2,4-D after pretreating the tissues with HEH. In pea, radish, and tomato plants, epinasty resulted from treatment with 2,4-D ethylamine, 2,4-D acetaldehyde and 2,4-D. Prior treatment with HEH prevented the epinasty due to the 2,4-D ethylamine, but no protection was given by HEH against 2,4-D acetaldehyde or 2,4-D.     

Detoxification of 2,4-dichlorophenol by the marine microalga Tetraselmis marina

Xenobiotic chlorinated phenols have been found in fresh and marine waters and are toxic to many aquatic organisms. Metabolism of 2,4-dichlorophenol (2,4-DCP) in the marine microalga Tetraselmis marina was studied. The microalga removed more than 1mM of 2,4-DCP in a 2l photobioreactor over a 6 day period. Two metabolites, more polar than 2,4-DCP, were detected in the growth medium by reverse phase HPLC and their concentrations increased at the expense of 2,4-DCP. The metabolites were isolated by a C8 HPLC column and identified as 2,4-dichlorophenyl-beta-d-glucopyranoside (DCPG) and 2,4-dichlorophenyl-beta-d-(6-O-malonyl)-glucopyranoside (DCPGM) by electrospray ionization-mass spectrometric analysis in a negative ion mode. The molecular structures of 2,4-DCPG and 2,4-CPGM were further confirmed by enzymatic and alkaline hydrolyses. Thus, it was concluded that the major pathway of 2,4-DCP metabolism in T. marina involves an initial conjugation of 2,4-DCP to glucose to form 2,4-dichlorophenyl-beta-d-glucopyranoside, followed by acylation of the glucoconjugate to form 2,4-dichlorophenyl-beta-d-(6-O-malonyl)-glucopyranoside. The microalga ability to detoxify dichlorophenol congeners other than 2,4-DCP was also investigated. This work provides the first evidence that microalgae can use a combined glucosyl and malonyl transfer to detoxify xenobiotics such as dichlorophenols.     

Growth Rates of a Pseudomonad on 2,4-Dichlorophenoxyacetic Acid and 2,4-Dichlorophenol

The growth of a pseudomonad on 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4-DCP (2,4-dichlorophenol) was studied in batch and continuous culture. The optimum growth rate using 2,4-D was 0.14/h at 25 C in a pH range from 6.2 to 6.9. Highest specific growth rate using 2,4-DCP was 0.12/h at 25 C in a pH range from 7.1 to 7.8. Growth was strongly inhibited by 2,4-DCP above a concentration of 25 mg/liter whereas no appreciable inhibition was observed with 2,4-D at concentrations up to 2,000 mg per liter. Growth on 2,4-DCP was described by Monod kinetics at subinhibitory concentrations but the inhibition by 2,4-DCP exhibited an unusual linear response to substrate concentration, and did not fit a model based on noncompetitive inhibition. The lag phase of batch cultures was found to depend on both 2,4-DCP concentration and prior adaptation of the inoculum. A study such as this on the kinetics of growth on related substrates may be useful as a method of finding the rate-limiting step in a metabolic sequence.     

Degradation of 2,4-dichlorophenoxyacetic acid by mixed cultures of bacteria

Summary We explored the feasibility of using mixed cultures for herbicide degradation, with the ultimate aim of application for effluent treatment. The present study reports on mixed cultures which were developed to grow aerobically with 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole carbon substrate. Degradation of 2,4-D was verified by HPLC and UV-spectroscopic analysis of the residual 2,4-D concentration in the test cultures. Cultures that were initially developed with 2,4-D also grew readily with glucose, but the degradation of 2,4-D was effectively prevented under mixed substrate conditions. Mamor intermediates or metabolites resulting from 2,4-D degradation were not detected with the HPLC methodology except 2,4-dichlorophenol which appeared to accumulate transiently in the growth medium.     

球形红细菌厌氧降解2,4-二硝基甲苯

【目的】研究不同环境条件对2,4-二硝基甲苯(2,4-DNT)生物降解的影响。【方法】采用光合细菌球形红细菌在温度为30 °C的光照培养箱中厌氧降解2,4-DNT,并用高效液相色谱仪测定其浓度。【结果】去除2,4-DNT的最佳条件是初始浓度40 mg/L、初始pH 7.0和接种量15%。另外,2,4-DNT在菌体延滞期被细胞吸收,然后在指数期作为碳源被降解。2,4-DNT的去除率在72 h达到98.8%。从液相色谱图中观察到有2种中间代谢产物,但在120 h内产物被逐渐降解。2,4-DNT的去除动力学符合一级速率模型。【结论】不同条件下2,4-DNT的去除率表明球形红细菌能有效降解2,4-DNT。     

Stimulation by 2,4-dichlorophenoxyacetic acid of betacyanin accumulation in suspension cultures of Phytolacca americana

2,4-Dichlorophenoxyacetic acid (2,4-D) strongly promoted betacyanin accumulation in suspension cultures of Phytolacca americana L. The betacyanin accumulation attained a maximum at 5 μ M 2,4-D, when betacyanin content per cell reached 252% as compared to the control (2,4-D free). 2,4-D elevated the level of free tyrosine, which is the precursor of betacyanin. The addition of 1 m M tyrosine to the medium partially reversed the reduction of betacyanin accumulation caused by the removal of 2,4-D. Tracer experiments using labelled tyrosine showed that 2,4-D activated the biosynthetic pathway from tyrosine to betacyanin. These results indicate that a sufficient supply of tyrosine and the activation of biosynthesis of betacyanin from tyrosine by 2,4-D elevate the level of betacyanin.     

Metabolism of 2,4-dichlorophenoxyacetic Acid in 2,4-dichlorophenoxyacetic Acid-resistant soybean callus tissue

Three 2,4-dichlorophenoxyacetic acid (2,4-D) -resistant root callus tissue lines of Glycine max L. Merrill var. Acme were derived by culturing callus tissue 2 to 6 months on 40 milligrams per liter 2,4-D and designated 40R, 40B, and 40C. Tissue line 40R had a lower level of 2,4-D uptake in 2-week-old tissue which disappeared in 3.5-week-old tissue and less free 2,4-D following incubation for 24 hours with [1-¹⁴C]2,4-D. This tissue line accumulated more hydroxylated glycosides of 2,4-D than did nonresistant tissue. Tissue line 40B showed no difference in uptake of 2,4-D when compared to nonresistant tissue but it did contain less free 2,4-D and more hydroxylated glycosides. The metabolism of 2,4-D in the 40C tissue line did not differ significantly from nonresistant tissue although uptake was less. The 40R line reverted to the same 2,4-D sensitivity as Acme root callus following six transfers on 10 micromolar naphthaleneacetic acid medium. The altered 2,4-D uptake and metabolism characteristic of 40R were also lost. The levels of amino acid conjugates of 2,4-D in the resistant root callus tissue lines were either lower or not significantly different from the Acme tissue lines. Therefore, variations in uptake and metabolism of 2,4-D do not wholly explain the resistance of the derived tissue lines, and perhaps modification of the active site or compartmentation is involved.     

Chemotaxis of Ralstonia eutropha JMP134(pJP4) to the Herbicide 2,4-Dichlorophenoxyacetate

Ralstonia eutropha JMP134(pJP4) and several other species of motile bacteria can degrade the herbicide 2,4-dichlorophenoxyacetate (2,4-D), but it was not known if bacteria could sense and swim towards 2,4-D by the process of chemotaxis. Wild-type R. eutropha cells were chemotactically attracted to 2,4-D in swarm plate assays and qualitative capillary assays. The chemotactic response was induced by growth with 2,4-D and depended on the presence of the catabolic plasmid pJP4, which harbors the tfd genes for 2,4-D degradation. The tfd cluster also encodes a permease for 2,4-D named TfdK. A tfdK mutant was not chemotactic to 2,4-D, even though it grew at wild-type rates on 2,4-D.     

2,4-D impact on bacterial communities, and the activity and genetic potential of 2,4-D degrading communities in soil

The key role of telluric microorganisms in pesticide degradation is well recognized but the possible relationships between the biodiversity of soil microbial communities and their functions still remain poorly documented. If microorganisms influence the fate of pesticides, pesticide application may reciprocally affect soil microorganisms. The objective of our work was to estimate the impact of 2,4-D application on the genetic structure of bacterial communities and the 2,4-D-degrading genetic potential in relation to 2,4-D mineralization. Experiments combined isotope measurements with molecular analyses. The impact of 2,4-D on soil bacterial populations was followed with ribosomal intergenic spacer analysis. The 2,4-D degrading genetic potential was estimated by real-time PCR targeted on tfdA sequences coding an enzyme specifically involved in 2,4-D mineralization. The genetic structure of bacterial communities was significantly modified in response to 2,4-D application, but only during the intense phase of 2,4-D biodegradation. This effect disappeared 7 days after the treatment. The 2,4-D degrading genetic potential increased rapidly following 2,4-D application. There was a concomitant increase between the tfdA copy number and the 14C microbial biomass. The maximum of tfdA sequences corresponded to the maximum rate of 2,4-D mineralization. In this soil, 2,4-D degrading microbial communities seem preferentially to use the tfd pathway to degrade 2,4-D.     

Chemotaxis of Ralstonia eutropha JMP134(pJP4) to the herbicide 2,4-dichlorophenoxyacetate

Ralstonia eutropha JMP134(pJP4) and several other species of motile bacteria can degrade the herbicide 2,4-dichlorophenoxyacetate (2,4-D), but it was not known if bacteria could sense and swim towards 2,4-D by the process of chemotaxis. Wild-type R. eutropha cells were chemotactically attracted to 2,4-D in swarm plate assays and qualitative capillary assays. The chemotactic response was induced by growth with 2,4-D and depended on the presence of the catabolic plasmid pJP4, which harbors the tfd genes for 2,4-D degradation. The tfd cluster also encodes a permease for 2,4-D named TfdK. A tfdK mutant was not chemotactic to 2,4-D, even though it grew at wild-type rates on 2,4-D.     

Oxidation of 2,4-dichlorophenol catalyzed by horseradish peroxidase: characterization of the reaction mechanism by UV-visible spectroscopy and mass spectrometry

The hydrogen peroxide-oxidation of 2,4-dichlorophenol catalyzed by horseradish peroxidase has been studied by means of UV-visible spectroscopy and mass spectrometry in order to clarify the reaction mechanism. The dimerization of 2,4-dichlorophenol to 2,4-dichloro-6-(2,4-dichlorophenoxy)-phenol and its subsequent oxidation to 2-chloro-6-(2,4-dichlorophenoxy)-1,4-benzoquinone together with chloride release were observed. The reaction rate was found to be pH-dependent and to be influenced by the pK(a) value of 2,4-dichlorophenol. The dissociation constants of the 2,4-dichlorophenol/horseradish peroxidase (HRP) adduct at pH 5.5 and 8.5 were also determined: their values indicate the unusual stability of the adduct at pH 5.5 with respect to several adducts of HRP with substituted phenols.     

Electron-impact mass spectrometry of methyl O-methylglucopyranosiduranamides

6-O-Acetyl-2,4-diazido-3-O-benzyl-2,4-dideoxy-β-D-glucopyranosyl chloride and 2,6-diazido-3,4-di-O-benzyl-2,6-dideoxy-β-D-glucopyranosyl chloride are two valuable building units suitable for the synthesis of α-linked disaccharides containing 2,4-diamino-2,4-dideoxy- or 2,6-diamino-2,6-dideoxy-D-glucose as nonreducing moieties. The glycoside synthesis is accomplished stereoselectively under mild conditions in the presence of silver perchlorate. The α-(1→3)-linked disaccharides 2,4-diacetamido-2,4-dideoxy-3-O-(2,4-diacetamido-2,4-dideoxy-α-D-glucopyranosyl)-D-glucopyranose and 2-acetamido-2-deoxy-3-O-(2,6-diacetamido-2,6-dideoxy-α-D-glucopyranosyl)-D-glucopyranose have been prepared.     

Quantitative Effects of 2,4-Dichlorophenoxyacetic Acid on Growth of Suspension-cultured Acer pseudoplatanus Cells: II. Influence of 2,4-D Metabolism and Intracellular pH on the Control of Cell Division by Intracellular 2,4-D Concentration

The utilization of 2,4-dichlorophenoxyacetic acid (2,4-D) molecules by Acer pseudoplatanus cells is governed mainly by a glucosylation process. Evidence that 2,4-D glucoside molecules are biologically inactive is presented. 2,3,5-Triiodobenzoic acid (TIBA), by inhibiting 2,4-D glucosylation, has a sparing effect on 2,4-D molecules; thus TIBA treatments increase growth yield (expressed as the ratio of the maximum number of cells produced to the initial concentration of 2,4-D in the culture medium).     

Bioremediation of 2,4-dinitrotoluene (2,4-DNT) in immobilized micro-organism biological filter

Aims: To evaluate the biodegradability of 2,4‐DNT using an anaerobic filter (AF) combined with a biological aerated filter (BAF), and elucidate the degradation mechanism of 2,4‐DNT and analyze the bacterial community of the reactors over a long period of operation. Methods and Results: The pilot test experienced wide fluctuations influent concentrations and there was lower than 0.50 mg l^?1 of 2,4‐DNT in the effluent of the system. The removal efficiency was above 99%. GC‐MS analysis demonstrated that 2,4‐DNT was mainly reduced to 2‐amino‐4‐nitrotoluene (2‐A‐4‐NT), 4‐amino‐2‐nitrotoluene (4‐A‐2‐NT), and 2,4‐diaminotoluene (2,4‐DAT) during the anaerobic reaction. In addition, ethanol was added into the influent as the electron donor. Because of the use of part ethanol as an auxiliary carbon source, more than twice the theoretical requirement of ethanol was needed to achieve a high 2,4‐DNT removal efficiency (>93%). ESEM observations showed that the carrier could immobilize micro‐organisms, which flourished more in reactors operating over longer periods. Further research by PCR‐DGGE revealed that new 2,4‐DNT‐resistant bacterial had been generated during the stress of 2,4‐DNT for 150 days. The dominant species for 2,4‐DNT degradation were identified by a comparison with gene sequences in GenBank. Conclusions: 2,4‐DNT could be effectively degraded by the combined process and ethanol played an important role in the biotransformation. The proposed transformation pathway of 2,4‐DNT was concluded. During the 150‐day operation, some microbial taxa unaccustomed to 2,4‐DNT died out and some new 2,4‐DNT‐resistant microbial taxa appeared. Significance and Impact of the Study: The study provides a novel method for the bioremediation of 2,4‐DNT, which is difficult to degrade by traditional biological methods. The most 2,4‐DNT‐resistant microbial taxa have not been reported elsewhere and they may be helpful to the treatment of actual 2,4‐DNT wastewater.     

厌氧条件下Shewanella oneidensis MR-1对2,4-二硝基甲苯的还原转化

【目的】研究Shewanella oneidensis MR-1厌氧生物转化2,4-二硝基甲苯(2,4-DNT)的能力、转化过程和影响因素。【方法】以乳酸钠为电子供体, 2,4-DNT为电子受体, S. oneidensis MR-1为降解菌, 黄素为胞外电子载体, 设立四个不同的对照体系并监测各体系在转化过程中2,4-DNT及其产物的动态变化。同时研究不同2,4-DNT浓度下细胞的生长情况, 以及不同黄素浓度下2,4-DNT的降解情况。【结果】S. oneidensis MR-1菌能够高效还原转化2,4-DNT为4-氨基-2-硝基甲苯(4A2NT)和2-氨基-4-硝基甲苯(2A4NT), 并将其进一步还原为2,4-二氨基甲苯(2,4-DAT), 黄素能加速转化过程。【结论】S. oneidensis MR-1菌具备高效还原转化2,4-DNT的能力, 为实际环境中硝基苯污染的原位修复提供科学依据。     

Gene probe analysis of soil microbial populations selected by amendment with 2,4-dichlorophenoxyacetic acid.

Soils with a history of 2,4-dichlorophenoxyacetic acid (2,4-D) treatment at field application rates and control soils with no prior exposure to 2,4-D were amended with 2,4-D in the laboratory. Before and during these treatments, the populations of 2,4-D-degrading bacteria were monitored by most-probable-number (MPN) enumeration and hybridization analyses, using probes for the tfd genes of plasmid pJP4, which encode enzymes for 2,4-D degradation. Data obtained by these alternate methods were compared. Several months after the most recent field application of 2,4-D (approximately 1 ppm), soils with a 42-year history of 2,4-D treatment did not have significantly higher numbers of 2,4-D-degrading organisms than did control soils with no prior history of treatment. In response to laboratory amendments with 2,4-D, both the previously treated soils and those with no prior history of exposure exhibited a dramatic increase in the number of 2,4-D-metabolizing organisms. The MPN data indicate a 4- to 5-log population increase after one amendment with 250 ppm of 2,4-D and ultimately a 6- to 7-log increase after four additional amendments, each with 400 ppm of 2,4-D. Similarly, when total bacterial DNA from the soil microbial community of these samples was analyzed by using a probe for the tfdA gene (2,4-D monoxygenase) or the tfdB gene (2,4-dichlorophenol hydroxylase) a dramatic increase in the level of hybridization was observed in both soils.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gene probe analysis of soil microbial populations selected by amendment with 2,4-dichlorophenoxyacetic acid.

Soils with a history of 2,4-dichlorophenoxyacetic acid (2,4-D) treatment at field application rates and control soils with no prior exposure to 2,4-D were amended with 2,4-D in the laboratory. Before and during these treatments, the populations of 2,4-D-degrading bacteria were monitored by most-probable-number (MPN) enumeration and hybridization analyses, using probes for the tfd genes of plasmid pJP4, which encode enzymes for 2,4-D degradation. Data obtained by these alternate methods were compared. Several months after the most recent field application of 2,4-D (approximately 1 ppm), soils with a 42-year history of 2,4-D treatment did not have significantly higher numbers of 2,4-D-degrading organisms than did control soils with no prior history of treatment. In response to laboratory amendments with 2,4-D, both the previously treated soils and those with no prior history of exposure exhibited a dramatic increase in the number of 2,4-D-metabolizing organisms. The MPN data indicate a 4- to 5-log population increase after one amendment with 250 ppm of 2,4-D and ultimately a 6- to 7-log increase after four additional amendments, each with 400 ppm of 2,4-D. Similarly, when total bacterial DNA from the soil microbial community of these samples was analyzed by using a probe for the tfdA gene (2,4-D monoxygenase) or the tfdB gene (2,4-dichlorophenol hydroxylase) a dramatic increase in the level of hybridization was observed in both soils.(ABSTRACT TRUNCATED AT 250 WORDS)