Reduction of polygalacturonase activity in tomato fruit by antisense RNA

Reduction of polygalacturonase activity in tomato fruit by antisense RNA.

Polygalacturonase [PG; poly(1,4-alpha-D-galacturonide) glycanhydrolase; EC 3.2.1.15] is expressed in tomato only during the ripening stage of fruit development. PG becomes abundant during ripening and has a major role in cell wall degradation and fruit softening. Tomato plants were transformed to produce antisense RNA from a gene construct containing the cauliflower mosaic virus 35S promoter an...

Polygalacturonase in normal and abnormal tomato fruit.

Autolysis of cell walls from polygalacturonase-antisense tomato fruit in simulated apoplastic solutions.

Autolysis of cell walls from polygalacturonase (PG)-antisense tomato fruit was studied in a conventional buffer designed to maximize the catalytic activity of PG (30 mM sodium acetate, 150 mM NaCl, pH 4.5), and in solutions mimicking the pH and mineral composition of the fruit apoplast at the mature-green and ripe stages. Autolytic release of uronic acids was very limited under simulated apopla...

In vitro synthesis and processing of tomato fruit polygalacturonase.

The in vitro processing of tomato fruit polygalacturonase (PG) (poly[1,4-alpha-d-galacturonide]glucanohydrolase, EC 3.2.1.15) was studied. Complete chemical deglycosylation of a mixture of mature, purified PG 2A and PG 2B isozymes (45 and 46 kilodaltons; respectively) with trifluoromethane sulfonic acid yielded a single polypeptide of 42 kilodaltons. Similarly, N-terminal amino acid sequencing ...

Reduction of tomato polygalacturonase beta subunit expression affects pectin solubilization and degradation during fruit ripening.

The developmental changes that accompany tomato fruit ripening include increased solubilization and depolymerization of pectins due to the action of polygalacturonase (PG). Two PG isoenzymes can be extracted from ripe fruit: PG2, which is a single catalytic PG polypeptide, and PG1, which is composed of PG2 tightly associated with a second noncatalytic protein, the beta subunit. Previous studies...