Differential Expression of the Two Subunits of Tomato Polygalacturonase Isoenzyme 1 in Wild-Type and rin Tomato Fruit.
AUTOR(ES)
Zheng, L.
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=159447Documentos Relacionados
- Differential Expression of Two Endo-1,4-[beta]-Glucanase Genes in Pericarp and Locules of Wild-Type and Mutant Tomato Fruit.
- Regulation of Gene Expression by Ethylene in Wild-Type and rin Tomato (Lycopersicon esculentum) Fruit 1
- Differential expression of two MADS box genes in wild-type and mutant petunia flowers.
- Molecular cloning of a ripening-specific lipoxygenase and its expression during wild-type and mutant tomato fruit development.
- Wild-type isopropylmalate isomerase in Salmonella typhimurium is composed of two different subunits.