Abstract
The [beta] subunit of tomato (Lycopersicon esculentum Mill.) fruit polygalacturonase 1 is a cell wall glycoprotein that binds to and apparently regulates the catalytic PG2 polypeptide in vivo. [beta] Subunit and polygalacturonase 2 (PG2) expression have been investigated in both wild-type and ripening inhibitor (rin) mutant fruit. During fruit development and ripening, [beta] subunit expression was unrelated to expression of the catalytic PG2 protein. In wild-type fruit, [beta] subunit mRNA and protein were first detected early in development and increased to maximal levels before PG2 mRNA and protein were detected. At the onset of ripening [beta] subunit mRNA decreased dramatically, but [beta] subunit protein levels remained stable. In rin fruit, which fail to ripen, [beta] subunit expression was similar to that in wild type, although PG2 mRNA and protein were not detected. These data suggest that [beta] subunit expression is ethylene independent and regulated primarily by developmental cues. This conclusion is supported by results from ethylene-treated immature (20 days after pollination) wild-type and rin fruit in which no significant differences were observed in [beta] subunit expression patterns in response to ethylene treatment. Surprisingly, RNA blot analysis indicated that catalytic PG2 mRNA was induced in immature rin fruit after 3 d of exogenous ethylene treatment. In addition, [beta] subunit mRNA and protein were also detected at lower levels in root, leaf, and flower tissues of both genotypes, suggesting a broader functional role for the protein.
Full Text
The Full Text of this article is available as a PDF (2.3 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allen R. L., Lonsdale D. M. Molecular characterization of one of the maize polygalacturonase gene family members which are expressed during late pollen development. Plant J. 1993 Feb;3(2):261–271. doi: 10.1111/j.1365-313x.1993.tb00177.x. [DOI] [PubMed] [Google Scholar]
- Brown S. M., Crouch M. L. Characterization of a gene family abundantly expressed in Oenothera organensis pollen that shows sequence similarity to polygalacturonase. Plant Cell. 1990 Mar;2(3):263–274. doi: 10.1105/tpc.2.3.263. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cathala G., Savouret J. F., Mendez B., West B. L., Karin M., Martial J. A., Baxter J. D. A method for isolation of intact, translationally active ribonucleic acid. DNA. 1983;2(4):329–335. doi: 10.1089/dna.1983.2.329. [DOI] [PubMed] [Google Scholar]
- Dellapenna D., Bennett A. B. In vitro synthesis and processing of tomato fruit polygalacturonase. Plant Physiol. 1988 Apr;86(4):1057–1063. doi: 10.1104/pp.86.4.1057. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dellapenna D., Kates D. S., Bennett A. B. Polygalacturonase Gene Expression in Rutgers, rin, nor, and Nr Tomato Fruits. Plant Physiol. 1987 Oct;85(2):502–507. doi: 10.1104/pp.85.2.502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Giovannoni J. J., DellaPenna D., Bennett A. B., Fischer R. L. Expression of a chimeric polygalacturonase gene in transgenic rin (ripening inhibitor) tomato fruit results in polyuronide degradation but not fruit softening. Plant Cell. 1989 Jan;1(1):53–63. doi: 10.1105/tpc.1.1.53. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gray J., Picton S., Shabbeer J., Schuch W., Grierson D. Molecular biology of fruit ripening and its manipulation with antisense genes. Plant Mol Biol. 1992 May;19(1):69–87. doi: 10.1007/BF00015607. [DOI] [PubMed] [Google Scholar]
- Herner R. C., Sink K. C. Ethylene Production and Respiratory Behavior of the rin Tomato Mutant. Plant Physiol. 1973 Jul;52(1):38–42. doi: 10.1104/pp.52.1.38. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lincoln J. E., Cordes S., Read E., Fischer R. L. Regulation of gene expression by ethylene during Lycopersicon esculentum (tomato) fruit development. Proc Natl Acad Sci U S A. 1987 May;84(9):2793–2797. doi: 10.1073/pnas.84.9.2793. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McGlasson W. B., Dostal H. C., Tigchelaar E. C. Comparison of Propylene-induced Responses of Immature Fruit of Normal and rin Mutant Tomatoes. Plant Physiol. 1975 Feb;55(2):218–222. doi: 10.1104/pp.55.2.218. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moshrefi M., Luh B. S. Carbohydrate composition and electrophoretic properties of tomato polygalacturonase isoenzymes. Eur J Biochem. 1983 Oct 3;135(3):511–514. doi: 10.1111/j.1432-1033.1983.tb07681.x. [DOI] [PubMed] [Google Scholar]
- Niogret M. F., Dubald M., Mandaron P., Mache R. Characterization of pollen polygalacturonase encoded by several cDNA clones in maize. Plant Mol Biol. 1991 Dec;17(6):1155–1164. doi: 10.1007/BF00028732. [DOI] [PubMed] [Google Scholar]
- Oeller P. W., Lu M. W., Taylor L. P., Pike D. A., Theologis A. Reversible inhibition of tomato fruit senescence by antisense RNA. Science. 1991 Oct 18;254(5030):437–439. doi: 10.1126/science.1925603. [DOI] [PubMed] [Google Scholar]
- Osteryoung K. W., Toenjes K., Hall B., Winkler V., Bennett A. B. Analysis of tomato polygalacturonase expression in transgenic tobacco. Plant Cell. 1990 Dec;2(12):1239–1248. doi: 10.1105/tpc.2.12.1239. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Themmen A. P., Tucker G. A., Grierson D. Degradation of isolated tomato cell walls by purified polygalacturonase in vitro. Plant Physiol. 1982 Jan;69(1):122–124. doi: 10.1104/pp.69.1.122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Theologis A. One rotten apple spoils the whole bushel: the role of ethylene in fruit ripening. Cell. 1992 Jul 24;70(2):181–184. doi: 10.1016/0092-8674(92)90093-r. [DOI] [PubMed] [Google Scholar]
- Tucker G. A., Robertson N. G., Grierson D. Changes in polygalacturonase isoenzymes during the 'ripening' of normal and mutant tomato fruit. Eur J Biochem. 1980 Nov;112(1):119–124. doi: 10.1111/j.1432-1033.1980.tb04993.x. [DOI] [PubMed] [Google Scholar]
- Zheng L., Heupel R. C., DellaPenna D. The beta subunit of tomato fruit polygalacturonase isoenzyme 1: isolation, characterization, and identification of unique structural features. Plant Cell. 1992 Sep;4(9):1147–1156. doi: 10.1105/tpc.4.9.1147. [DOI] [PMC free article] [PubMed] [Google Scholar]