Increase of Mitochondrial Fraction in Sweet Potato Root Tissue after Wounding or Infection with Ceratocystis fimbriata

Abstract

The acid-insoluble N and lipid contents, and cytochrome oxidase and succinate dehydrogense activities in mitochondrial fraction were found to increase during incubation of slices of sweet potato root tissue. The number of Janus green B-stained particles in the mitochondrial fraction also was found to increase during the incubation. The increase in the mitochondrial fraction was not due to the cell division during the incubation, since these increases were observed even in the inner parts at a distance of 3-4 mm from the cut surface. The N content m the mitochondrial fraction increased prior to the changes in cytochrome oxidase activity and lipid content. The increase in the number of Janus green B-stained particles lagged behind the increases in the mitochondrlal components. Such findings were also found in tissue infected by Ceratocystis fimbriata. The respiratory increase in response to wounding and infection may be a result of an increase in mitochondrial particles.