Genetics of the peroxidase isoenzymes inPetunia : 10. Location of the geneprxD.

The structural geneprxD inPetunia codes for a slow moving anodic peroxidase whose activity is sensitive to high concentrations of hydrogen peroxide. The PRXd enzyme could be found in mature and old leaf and stem tissue of full-grown flowering plants. PRXd was found to be absent in tissues from flower corolla and root. The geneprxD is the fourth gene that codes for peroxidases in leaf and stem. Two mobility variants of the PRXd enzyme have been found among our inbred lines using starch gel system II electrophoresis. The geneprxD could be located on chromosome III by a four-point-cross involving the genesprxA, prxD, Mf1 andHt1. The order of the genes established is:Ht1 - Mf1 - prxD - prxA.