Cycloheximide Stimulation of Cyanide-Resistant Respiration in Suspension Cultures of Senescent Pear Fruit Cells

Pear fruit cells undergoing a period of senescence in auxin-deprived media develop a substantial cyanide resistant respiration in response to the addition of 0.7 to 3.5 micromolar cycloheximide. The inhibitor does not affect overall cellular repiratory activity and titrations with salicylhydroxamic acid reveal that only a minor portion, about 10%, of the alternate pathway is utilized by the cycloheximide-treated senescent cells. The alternate respiratory pathway appears to be of mitochondrial origin but is not induced by chloramphenicol.