Peroxidase Isozyme Patterns Research Articles

Histochemical Localization of Enzymes in the Abscission Zones of Maturing Sour and Sweet Cherry Fruit1

Abstract Dehydrogenase, acid phosphatase, and peroxidase activities were localized histochemically in the lower (pedicel-fruit) abscission zones of sour (Prunus cerasus L.) and sweet (Prunus avium L.) cherry fruits. Highest enzyme activity generally occurred at the juncture of the receptacle and fruit tissues; the region where separation occurred. Both species had a similar peroxidase isozyme pattern; however, 2 bands in sweet cherry had lower intensities than sour cherry. The implications of localized activities of these enzymes in cherry fruit abscission are discussed.

Peroxidase Localization, Activity, and Isozyme Patterns in the Developing Seedling of Vanda (Orchidaceae)

Peroxidase Localization, Activity, and Isozyme Patterns in the Developing Seedling of Vanda (Orchidaceae)

Tuber proteins from haploids, selfs, and cultivars of group tuberosum separated by acid gel disc electrophoresis

Tuber extracts of 46 cultivars (American varieties), and 350 haploids (2n=24) and selfs (2n=48) from four parents (2n=48), were analysed by acid gel disc electrophoresis. This system separated proteins into 12-14 bands. Twelve cultivars possessed unique patterns of bands, and the remaining cultivars could be placed in groups on the basis of 8 different banding patterns. Distinctions between varieties within groups was accomplished by either esterase or peroxidase isozyme patterns. The usefulness of basic gel proteins, esterase, and peroxidases for varietal identification is known; the acid gel protein patterns described provide a fourth system.Proteins from haploids and selfs were examined for variation in frequency and presence of bands. Differences among bands of the 4 parents were minor. Most haploids and selfs possessed the same bands as their parents, but there were interesting exceptions. The frequency of certain bands was significantly higher in selfs than in haploids. The results fit what would be expected if the parent tetraploid is simplex for a dominant allele controlling the production of each protein. Other bands are more frequent in haploids than selfs and some bands are present in haploids and not in the parent. Suppressor genes in the tetraploids may account for these latter results.