Pectinesterase in normal and abnormal tomato fruit.

Silencing of the major salt-dependent isoform of pectinesterase in tomato alters fruit softening.

Pectinesterase (PE; E.C. 3.1.1.11) is an enzyme responsible for the demethylation of galacturonyl residues in high-molecular-weight pectin and is believed to play an important role in cell wall metabolism. In this study, Pmeu1, a ubiquitously expressed PE gene, has been characterized by antisense suppression in tomato (Solanum lycopersicum). Transgenic tomato plants showed reduced PE activity l...

Developmental abnormalities and reduced fruit softening in tomato plants expressing an antisense Rab11 GTPase gene.

A cDNA clone from tomato fruit encodes a protein with strong homology with the rab11/YPT3 class of small GTPases that is thought to be involved in the control of protein trafficking within cells. The gene, LeRab11a, showed a pattern consistent with a single copy in DNA gel blots. The corresponding mRNA was developmentally regulated during fruit ripening, and its expression was inhibited in seve...

Tomato fruit cell wall : I. Use of purified tomato polygalacturonase and pectinmethylesterase to identify developmental changes in pectins.

Cell wall isolation procedures were evaluated to determine their effect on the total pectin content and the degree of methylesterification of tomato (Lycopersicon esculentum L.) fruit cell walls. Water homogenates liberate substantial amounts of buffer soluble uronic acid, 5.2 milligrams uronic acid/100 milligrams wall. Solubilization appears to be a consequence of autohydrolysis mediated by po...

Polygalacturonase in normal and abnormal tomato fruit.

Molecular cloning of tomato pectin methylesterase gene and its expression in rutgers, ripening inhibitor, nonripening, and never ripe tomato fruits.

We have purified pectin methylesterase (PME; EC 3.1.11) from mature green (MG) tomato (Lycopersicon esculentum Mill. cv Rutgers) pericarp to an apparent homogeneity, raised antibodies to the purified protein, and isolated a PME cDNA clone from a lambdagtll expression library constructed from MG pericarp poly(A)(+) RNA. Based on DNA sequencing, the PME cDNA clone isolated in the present study is...