Effects of nuclear restorer genes on the cytochrome content of corn pollen mitochondria

Abstract

Mitochondria were isolated from mature pollen grains of corn (Zea mays L.) having normal (N) or restored Texas male-sterile (TRf) cytoplasm. Comparison of the cytochrome content of the two sources by low-temperature difference spectroscopy indicates that inbred lines carrying nuclear restorer genes and T cytoplasm have an increased cytochrome oxidase content. A lower cytochrome oxidase concentration was found in mitochondria isolated from anthers of nonrestored Texas (cms-T) male-sterile cytoplasm corn than from those isolated from nonexserted anthers of N or TRf plants. Mitochondria in nonsporogenous tissue of cms-T anthers collected just before the time of anthesis of N plants had fewer well defined cristae than mitochondria in comparable anther tissue of N or TRf plants.