Polygalacturonase in normal and abnormal tomato fruit

Polygalacturonase in normal and abnormal tomato fruit.

Pectinesterase in normal and abnormal tomato fruit.

Although the pectin content of tomatoes is relatively low in comparison with other fruits (Money & Christian, 1950), the activity of pectinesterase (pectin pectyl-hydrolase, EC 3.1.1.11) is particularly high (Kertesz, 1938). Softening of the fruit takes place relatively rapidly during ripening (Hobson, 1959), and the classical mechanism by which the effect is usually explained assumes the solub...

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 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...

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...