Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1994 Oct;106(2):429–436. doi: 10.1104/pp.106.2.429

Reduction in Pectin Methylesterase Activity Modifies Tissue Integrity and Cation Levels in Ripening Tomato (Lycopersicon esculentum Mill.) Fruits.

D M Tieman 1, A K Handa 1
PMCID: PMC159547  PMID: 12232340

Abstract

Pectin methylesterase (PME, EC 3.1.1.11) is an ubiquitous enzyme in the plant kingdom; however, its role in plant growth and development is not yet understood. Using transgenic tomato (Lycopersicon esculentum Mill.) fruits that show more than 10-fold reduction in PME activity because of expression of an antisense PME gene, we have investigated the role of PME in tomato fruit ripening. Our results show that reduced PME activity causes an almost complete loss of tissue integrity during fruit senescence but shows little effect on fruit firmness during ripening. Low PME activity in the transgenic fruit pericarp modified both accumulation and partitioning of cations between soluble and bound forms and selectively impaired accumulation of Mg2+ over other major cations. Decreased PME activity was associated with a 30 to 70% decrease in bound Ca2+ and Mg2+ in transgenic pericarp. Levels of soluble Ca2+ increase 10 to 60%, whereas levels of soluble Mg2+ and Na+ are reduced by 20 to 60% in transgenic pericarp. Changes in cation levels associated with lowered PME activity do not affect the rate of respiration or membrane integrity of fruit during ripening. Overall, these results suggest that PME plays a role in determining tissue integrity during fruit senescence, perhaps by regulating cation binding to the cell wall.

Full Text

The Full Text of this article is available as a PDF (2.2 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Biggs M. S., Handa A. K. Temporal regulation of polygalacturonase gene expression in fruits of normal, mutant, and heterozygous tomato genotypes. Plant Physiol. 1989 Jan;89(1):117–125. doi: 10.1104/pp.89.1.117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Carrington CMS., Greve L. C., Labavitch J. M. Cell Wall Metabolism in Ripening Fruit (VI. Effect of the Antisense Polygalacturonase Gene on Cell Wall Changes Accompanying Ripening in Transgenic Tomatoes). Plant Physiol. 1993 Oct;103(2):429–434. doi: 10.1104/pp.103.2.429. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Koch J. L., Nevins D. J. Tomato fruit cell wall : I. Use of purified tomato polygalacturonase and pectinmethylesterase to identify developmental changes in pectins. Plant Physiol. 1989 Nov;91(3):816–822. doi: 10.1104/pp.91.3.816. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Liners F., Letesson J. J., Didembourg C., Van Cutsem P. Monoclonal Antibodies against Pectin: Recognition of a Conformation Induced by Calcium. Plant Physiol. 1989 Dec;91(4):1419–1424. doi: 10.1104/pp.91.4.1419. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Lynch M. A., Staehelin L. A. Domain-specific and cell type-specific localization of two types of cell wall matrix polysaccharides in the clover root tip. J Cell Biol. 1992 Jul;118(2):467–479. doi: 10.1083/jcb.118.2.467. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Morris E. R., Powell D. A., Gidley M. J., Rees D. A. Conformations and interactions of pectins. I. Polymorphism between gel and solid states of calcium polygalacturonate. J Mol Biol. 1982 Mar 15;155(4):507–516. doi: 10.1016/0022-2836(82)90484-3. [DOI] [PubMed] [Google Scholar]
  7. Powell D. A., Morris E. R., Gidley M. J., Rees D. A. Conformations and interactions of pectins. II. Influences of residue sequence on chain association in calcium pectate gels. J Mol Biol. 1982 Mar 15;155(4):517–531. doi: 10.1016/0022-2836(82)90485-5. [DOI] [PubMed] [Google Scholar]
  8. Rexová-Benková L., Markovic O. Pectic enzymes. Adv Carbohydr Chem Biochem. 1976;33:323–385. doi: 10.1016/s0065-2318(08)60285-1. [DOI] [PubMed] [Google Scholar]
  9. Saltveit M. E. Effect of alcohols and their interaction with ethylene on the ripening of epidermal pericarp discs of tomato fruit. Plant Physiol. 1989 May;90(1):167–174. doi: 10.1104/pp.90.1.167. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Suwwan M. A., Poovaiah B. W. Association between Elemental Content and Fruit Ripening in rin and Normal Tomatoes. Plant Physiol. 1978 Jun;61(6):883–885. doi: 10.1104/pp.61.6.883. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Tieman D. M., Harriman R. W., Ramamohan G., Handa A. K. An Antisense Pectin Methylesterase Gene Alters Pectin Chemistry and Soluble Solids in Tomato Fruit. Plant Cell. 1992 Jun;4(6):667–679. doi: 10.1105/tpc.4.6.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Varner J. E., Taylor R. New ways to look at the architecture of plant cell walls : localization of polygalacturonate blocks in plant tissues. Plant Physiol. 1989 Sep;91(1):31–33. doi: 10.1104/pp.91.1.31. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Walkinshaw M. D., Arnott S. Conformations and interactions of pectins. II. Models for junction zones in pectinic acid and calcium pectate gels. J Mol Biol. 1981 Dec 25;153(4):1075–1085. doi: 10.1016/0022-2836(81)90468-x. [DOI] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES