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)

Tomato fruit maturation is accompanied by a depolymerization of cell wall pectins which is due to the action of endopolygalacturonase (endoPG) preceded by pectin methylesterase (PE) activity. To investigate the role of endoPG and PE in determining the structure of green bean (Phaseolus vulgaris L.) pectins, these pectinases were studied during pod development. Early developmental stages displayed low endoPG or exoPG activities while PE activities were measurable during all stages of pod and seed development. These results do not favour a possible synergistic action of PE and PG. For seeds, the relatively high PE activities concurred with relatively low levels of pectin methyl esterification. At a molecular level, one partial chromosomal clone of 210 bp (PE1V), two partial PE cDNA clones of 660 bp (PE2V and PE3V) from cv. verona and one full-length PE cDNA clone of 1990 bp (PE3M), from cv. Masai were isolated. The identity of the CDNA clones was confirmed by expression in Escherichia coli and immunodetection with antibodies directed towards a tomato fruit PE. Transcripts corresponding with the genomic clone PE1V were not detected but both PE2 and PE3 cDNAs corresponded with mRNAs 1.8 kb in length. In contrast to PE2, PE3 gene expression levels varied significantly in pods from different cultivars suggesting an involvement in determining pod morphology.
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PMID:Characterization of pectinases and pectin methylesterase cDNAs in pods of green beans (Phaseolus vulgaris L.). 891 30

The Colorless non-ripening (Cnr) mutation in tomato (Solanum lycopersicum) results in mature fruits with colorless pericarp tissue showing an excessive loss of cell adhesion (A.J. Thompson, M. Tor, C.S. Barry, J. Vrebalov, C. Orfila, M.C. Jarvis, J.J. Giovannoni, D. Grierson, G.B. Seymour [1999] Plant Physiol 120: 383-390). This pleiotropic mutation is an important tool for investigating the biochemical and molecular basis of cell separation during ripening. This study reports on the changes in enzyme activity associated with cell wall disassembly in Cnr and the effect of the mutation on the program of ripening-related gene expression. Real-time PCR and biochemical analysis demonstrated that the expression and activity of a range of cell wall-degrading enzymes was altered in Cnr during both development and ripening. These enzymes included polygalacturonase, pectinesterase (PE), galactanase, and xyloglucan endotransglycosylase. In the case of PE, the protein product of the ripening-related isoform PE2 was not detected in the mutant. In contrast with wild type, Cnr fruits were rich in basic chitinase and peroxidase activity. A microarray and differential screen were used to profile the pattern of gene expression in wild-type and Cnr fruits. They revealed a picture of the gene expression in the mutant that was largely consistent with the real-time PCR and biochemical experiments. Additionally, these experiments demonstrated that the Cnr mutation had a profound effect on many aspects of ripening-related gene expression. This included a severe reduction in the expression of ripening-related genes in mature fruits and indications of premature expression of some of these genes in immature fruits. The program of gene expression in Cnr resembles to some degree that found in dehiscence or abscission zones. We speculate that there is a link between events controlling cell separation in tomato, a fleshy fruit, and those involved in the formation of dehiscence zones in dry fruits.
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PMID:Effect of the Colorless non-ripening mutation on cell wall biochemistry and gene expression during tomato fruit development and ripening. 1556 27