Differential regulation of peroxidase isozymes coded by Px-1 locus in ricer1

Abstract

Alleles of Px^2A and Px^4A at the Px-1 locus in wild and cultivated rice strains code dimeric peroxidase isozymes, which were detected zymographically with lemmata and paleae at higher intensity as well as with leaf blade and leaf sheath at lower intensity. In a heterozygote, Px^2APx^4A, three isozyme bands 2A, 3A and 4A appear. Distinct differences in the intensity ratio of the bandmorphs were observed, and they were classified into types I to V. A cross between Japonica sativa and Asian perennis showed type I only. Another cross between two strains of Asian perennis showed type II only, but a cross between Japonica sativa and African perennis showed types I to III. A receptor mutant gene adjacent to the Px-1 locus and two regulator gene loci independent from the Px-1 locus were assumed to account for the inheritance.