DEMETHYLATION OF RIPENING SPECIFIC GENES IN TOMATO FRUIT

To assess whether demethylation might play a role in the regulation of genes involved in ripening we investigated the changes in methylation levels of two ripening specific genes. DNA was extracted from tomato fruit (Lycopersicon esculentum, var. Castelemart) at progressive stage s of ripening and digested with the isoschizomer pair HpaII/MspI. Sout hern blot analyses revealed a decrease in methylation of sequences con taining the genes encoding polygalacturonase and cellulase coincident with the onset of ripening. No differences in methylation levels were observed when LHA1, a constitutively expressed gene not likely subject to changes in methylation, was used as a probe. It would appear that demethylation of specific genes may be involved in the epigenetic cont rol of fruit ripening.