Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.15 (pectinase)
2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hydrogen isotope-effect that occurs in vitro during myo-inositol1-phosphate synthase-catalyzed conversion of D-[5-3H]glucose 6-phosphate into myo[2-3H]inositol 1-phosphate has been used to compare the functional role of the nucleotide sugar oxidation-pathway with that of the myo-inositol oxidation-pathway in germinating lily pollen. Results reveal a significant difference between the 3H/14C ratios of glucosyl and galactosyluronic residues from pectinase-amyloglucosidase hydrolyzates of the 70% ethanol-insoluble fraction of D-[5-3H, 1-14C]glucose-labeled, germinating lily pollen. This isotope effect at C-5 of D-glucose that occurred during its conversion into D-galactosyluronic residues of pectic substance is not explained by loss of 3H when UDP-D-[5-3H, 1-14C]glucose is oxidized by UDP-D-glucose dehydrogenase from germinating lily pollen. The evidence obtained from this study favors a functional role for the myo-inositol oxidation-pathway during in vivo conversion of glucose into galactosyluronic residues of pectin in germinating lily pollen.
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PMID:The C-5 hydrogen isotope-effect in myo-inositol 1-phosphate synthase as evidence for the myo-inositol oxidation-pathway. 699 81

Extensin, a major hydroxyproline (Hyp)-rich glycoprotein in walls of cultured cells of dicotyledonous plants, is very difficult to solubilize. To learn about the nature of the insolubilization, we have tested the ability of a variety of selective hydrolytic methods, and combinations of them, to liberate extensin or fragments of extensin from suspension-culture cell walls. After the complete deglycosylation of cotton (Gossypium hirsutum L.) walls, trypsinization solubilized 80% of the Hyp. The sequences of three abundant peptides were: (a) serine-Hyp-Hyp-Hyp-Hyp-Hyp-Hyp-serine-Hyp-Hyp-lysine, (b) serine-Hyp-Hyp-Hyp-Hyp-valine-lysine, and (c) serine-Hyp-Hyp-serine-alanine-Hyp-lysine. After a sequential treatment of walls with endopolygalacturonase, cellulase, -73 degrees C anhydrous hydrogen fluoride solvolysis, and ammonium bicarbonate extraction, only sugars indicative of rhamnogalacturonan I and protein remained insoluble. Trypsin treatment of this residue liberated 50% of the Hyp. A significant proportion of rhamnogalacturonan-associated sugars co-solubilized and co-purified along with the extensin fragments following the trypsinization. By sodium dodecyl sulfate gel electrophoresis and gel filtration, the glycopeptides fell into two classes. One class contained distinctly sized molecules with relative molecular weights in the range of 4,000 to 24,000. The other class did not enter the resolving gel and was hetero-disperse. After complete deglycosylation by a 0 degrees C anhydrous hydrogen fluoride treatment, the first class was little affected in its electrophoretic mobility, whereas the larger heterogeneous material mostly entered the separating gel. After further trypsinization of the deglycosylated peptides and analysis by capillary zone electrophoresis, the peptides in both size classes were shown to contain the sequences described above. From our observations we suggest that cotton extensin becomes insolubilized into cell walls in part by pectin-protein cross-links in addition to the protein-protein (or protein-phenolic-protein) cross-links that have been repeatedly suggested.
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PMID:Solubilization and partial characterization of extensin fragments from cell walls of cotton suspension cultures. Evidence for a covalent cross-link between extensin and pectin. 765 56

RpoS (sigma-S or sigma-38) controls a large array of genes that are expressed during stationary phase and under various stress conditions in Escherichia coli and other bacteria. We document here that plant pathogenic and epiphytic Erwinia species, such as E. amylovora; E. carotovora subsp. atroseptica, betavasculorum, and carotovora; E. chrysanthemi; E. herbicola; E. rhapontici; and E. stewartii, possess rpoS genes and produce the alternate sigma factor. We show that rpoS transcription in E. carotovora subsp. carotovora is driven from a major promoter which resides within the nlpD gene located upstream of rpoS as in E. coli. RpoS- E. carotovora subsp. carotovoa strain AC5061, constructed by marker exchange, is more sensitive to hydrogen peroxide, carbon starvation, and acidic pH than its RpoS+ parent strain, AC5006. The basal levels of extracellular pectate lyase, polygalacturonase, and cellulase as well as those of transcripts of E. carotovora subsp. carotovora hrpN (hrpNEcc), the gene for the elicitor of the hypersensitive reaction, are higher in the RpoS- strain than in the RpoS+ parent. Likewise, compared to AC5006, AC5061 causes more extensive maceration of celery petioles. Our findings with the RpoS- mutant and strains carrying multiple copies rpoS+ DNA reveal that rpoS positively controls rsmA expression. We also present evidence that supports the hypothesis that the RpoS effect on extracellular enzyme levels, hrpNEcc expression, and virulence manifests itself by the modulation of rsmA expression.
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PMID:RpoS (sigma-S) controls expression of rsmA, a global regulator of secondary metabolites, harpin, and extracellular proteins in Erwinia carotovora. 965 7

Neutral xyloglucan was purified from the cell walls of suspension-cultured rose (Rosa sp. 'Paul's Scarlet') cells by alkali extraction, ethanol precipitation and anion-exchange chromatography on 'Q-Sepharose FastFlow'. The procedure recovered 70% of the total xyloglucan at about 95% purity in the neutral fraction. The remaining 30% of the xyloglucan was anionic, as demonstrated both by anion-exchange chromatography at pH 4.7 and by high-voltage electrophoresis at pH 6.5. Alkali did not cause neutral xyloglucan to become anionic, indicating that the anionic nature of the rose xyloglucan was not an artefact of the extraction procedure. Pre-incubation of neutral [3H]xyloglucan with any of ten non-radioactive acidic polysaccharides did not cause the radioactive material to become anionic as judged by electrophoresis, indicating that stable complexes between neutral xyloglucan and acidic polysaccharides were not readily formed in vitro. The anionic xyloglucan did not lose its charge in the presence of 8 M urea or after a second treatment with NaOH, indicating that its anionic nature was not due to hydrogen-bonding of xyloglucan to an acidic polymer. Proteinase did not affect the anionic xyloglucan, indicating that it was not associated with an acidic protein. Cellulase converted the anionic xyloglucan to the expected neutral nonasaccharide and heptasaccharide, indicating that the repeatunits of the xyloglucan did not contain acidic residues. Endo-polygalacturonase converted about 40% of the anionic xyloglucan to neutral material. Arabinanase and galactanase also converted appreciable proportions of the anionic xyloglucan to neutral material. These results show that about 30% of the xyloglucan in the cell walls of suspension-cultured rose cells exists in covalently-linked complexes with acidic pectins.
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PMID:Evidence for covalent linkage between xyloglucan and acidic pectins in suspension-cultured rose cells. 1094 22

The systemic accumulation of both hydrogen peroxide (H(2)O(2)) and proteinase inhibitor proteins in tomato leaves in response to wounding was inhibited by the NADPH oxidase inhibitors diphenylene iodonium (DPI), imidazole, and pyridine. The expression of several defense genes in response to wounding, systemin, oligosaccharides, and methyl jasmonate also was inhibited by DPI. These genes, including those of four proteinase inhibitors and polyphenol oxidase, are expressed within 4 to 12 hr after wounding. However, DPI did not inhibit the wound-inducible expression of genes encoding prosystemin, lipoxygenase, and allene oxide synthase, which are associated with the octadecanoid signaling pathway and are expressed 0.5 to 2 hr after wounding. Accordingly, treatment of plants with the H(2)O(2)-generating enzyme glucose oxidase plus glucose resulted in the induction of only the later-expressed defensive genes and not the early-expressed signaling-related genes. H(2)O(2) was cytochemically detected in the cell walls of vascular parenchyma cells and spongy mesophyll cells within 4 hr after wounding of wild-type tomato leaves, but not earlier. The cumulative results suggest that active oxygen species are generated near cell walls of vascular bundle cells by oligogalacturonide fragments produced by wound-inducible polygalacturonase and that the resulting H(2)O(2) acts as a second messenger for the activation of defense genes in mesophyll cells. These data provide a rationale for the sequential, coordinated, and functional roles of systemin, jasmonic acid, oligogalacturonides, and H(2)O(2) signals for systemic signaling in tomato plants in response to wounding.
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PMID:Hydrogen peroxide acts as a second messenger for the induction of defense genes in tomato plants in response to wounding, systemin, and methyl jasmonate. 1115 38

Tomato (Lycopersicon esculentum var. Better Boy) plants were transformed with a tomato leaf wound-inducible polygalacturonase (PG) beta-subunit gene in the antisense orientation (PGbetaS-AS) under the control of the cauliflower mosaic virus 35S promoter. The leaves of the transgenic plants exhibited small localized lesions, which eventually enlarged and spread throughout the entire surfaces of the leaves, resulting in cell death. The same lesions were also observed in the peduncle of developing flowers, extending to the whole flower causing abscission, resulting in a sterile phenotype. Leaves of transgenic plants exhibited elevated levels of PG activity, hydrogen peroxide, and enhanced defense signaling in response to wounding and elicitor treatment. The defense signaling increased was accompanied by an increased resistance toward tobacco hornworm (Manduca sexta) larvae. The cumulative results suggest that in the absence of the beta-subunit protein in tomato leaves, an increase in PG activity occurred that led to an enhanced wound response, the formation of lesions leading to severe necrosis, and an abscission of developing flowers.
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PMID:Polygalacturonase beta-subunit antisense gene expression in tomato plants leads to a progressive enhanced wound response and necrosis in leaves and abscission of developing flowers. 1297 68

The characterization of 23 Lactobacillus strains was performed. The strains were assayed for biogenic amine-forming capacity, hydrogen peroxide production, pectin esterase, cellulase and polygalacturonase production, growth rate, acidifying capacity and salt tolerance. Three strains were selected which belonged to the species, Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus fermentum. Different starter cultures prepared as combinations of these three strains were assayed in pilot scale fermentations and Randomly Amplified Polymorphic DNA (RAPD) analysis, using a previously selected random primer, was applied for monitoring the inoculated strains. The course of fermentations was similar in all batches but sensorial analysis of eggplants fermented using a mixed culture of the three strains displayed the best results, and no differences were obtained when compared with commercial eggplants.
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PMID:Characterization of Lactobacillus strains and monitoring by RAPD-PCR in controlled fermentations of "Almagro" eggplants. 1597 83

The diversity and antifungal activity of fluorescent pseudomonads isolated from rhizospheres of tea, gladiolus, carnation and black gram grown in acidic soils with similar texture and climatic conditions were studied. Biochemical characterisation including antibiotic resistance assay, RAPD and PCR-RFLP studies revealed a largely homogenous population. At soil pH (5.2), the isolates exhibited growth with varying levels of siderophore production, irrespective of crop rhizospheres. Two isolates with maximum chitinase production showed antagonism. The bacterial populations in general lacked the ability to produce deleterious traits such as cellulase, pectinase and hydrogen cyanide. However, increased pH levels beyond 5.2 caused reduction in metabolite production with reduced antifungal activity. The homogeneity of the bacterial population irrespective of crop rhizospheres together with decreased secondary metabolite production at higher pH levels reinstated the importance of soil over host plant in influencing rhizosphere populations. The studies also yielded acid tolerant chitinase producing antagonistic fluorescent pseudomonads.
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PMID:Influence of soil reaction on diversity and antifungal activity of fluorescent pseudomonads in crop rhizospheres. 1684 55

Pectins were extracted from roots and petioles of sugar beet, and treated with alpha-arabinosidase, 1,4-beta-galactanase or polygalacturonase. They were then cross-linked using hydrogen peroxide and peroxidase. The effects on pectin molecular size were monitored by size-exclusion chromatography and viscometry. A decrease in apparent molecular size was observed after alpha-arabinosidase and polygalacturonase treatment, and all three enzymes caused a decrease in viscosity. The pectins were then cross-linked using hydrogen peroxide and peroxidase, and the effects on dehydrodiferulate formation were monitored by HPLC. Pretreatment with polygalacturonase caused no significant change in subsequent dehydrodiferulate cross-linking, while pretreatment with alpha-arabinosidase caused a slight change in the ratios of the different dehydrodiferulates formed. Pretreatment with 1,4-beta-d-galactanase caused a more significant change in the ratios of the different dehydrodiferulates formed, and also greatly increased the overall recovery of total ferulates (monomers plus dehydrodiferulates), both in root pectin and petiole pectin. The possible effects of polysaccharide microstructure on the dimerisation and further polymerisation of pectin-linked ferulates are discussed.
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PMID:Effects of partial enzymic degradation of sugar beet pectin on oxidative coupling of pectin-linked ferulates in vitro. 1752 39

Eight bacterial isolates from the larval guts of Diamondback moths (Plutella xylostella) were tested for their plant growth-promoting (PGP) traits and effects on early plant growth. All of the strains tested positive for nitrogen fixation and indole 3-acetic acid (IAA) and salicylic acid production but negative for hydrogen cyanide and pectinase production. In addition, five of the isolates exhibited significant levels of tricalcium phosphate and zinc oxide solubilization; six isolates were able to oxidize sulfur in growth media; and four isolates tested positive for chitinase and beta-1,3-glucanase activities. Based on their IAA production, six strains including four that were 1-aminocyclopropane-1-carboxylate (ACC) deaminase positive and two that were ACC deaminase negative were tested for PGP activity on the early growth of canola and tomato seeds under gnotobiotic conditions. Acinetobacter sp. PSGB04 significantly increased root length (41%), seedling vigor, and dry biomass (30%) of the canola test plants, whereas Pseudomonas sp. PRGB06 inhibited the mycelial growth of Botrytis cinerea, Colletotrichum coccodes, C. gleospoiroides, Rhizoctonia solani, and Sclerotia sclerotiorum under in vitro conditions. A significant increase, greater than that of the control, was also noted for growth parameters of the tomato test plants when the seeds were treated with PRGB06. Therefore, the results of the present study suggest that bacteria associated with insect larval guts possess PGP traits and positively influence plant growth. Therefore, insect gut bacteria as effective PGP agents represent an unexplored niche and may broaden the spectrum of beneficial bacteria available for crop production.
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PMID:Characterization of plant growth-promoting traits of bacteria isolated from larval guts of diamondback moth Plutella xylostella (lepidoptera: plutellidae). 1817 18


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