Development of cyanide-resistant respiration in mitochondria from potato tubers treated with ethanol,acetaldehyde, and acetic acid

Treatment of intact potato (Solanum tuberosum L.) tubers with acetaldehyde, ethanol or acetic-acid vapors led to a respiratory upsurge which was further increased when the volatiles were applied in 100% O₂. Mitochondria from tubers held in 100% O₂ (O₂ control) displayed a substrate state, state 3, and state 4 in respiration, whereas in mitochondria from the volatile-treated tubers the respiratory rate of the different states was virtually indistinguishable. This respiratory pattern was companied by the development of a cyanide-resistant respiration since these mitochondria exhibited resistance to CN and sensitivity to CN+salicylhydroxamic acid. Acetaldehyde-treated potatoes showed a time-course development (up to 36 h) of cyanide resistance and concomitant sensitivity to salicylhydroxamic acid, indicating the onset of synthetic processes leading to the observed changes in mitochondrial respiration.Abbreviations V total respiration rate - V_cyt velocity of O₂ uptake attributable to cytochrome oxidase - V_alt velocity of O₂ uptake attributable to the alternate oxidase - RCR respiratory control ratio - SHAM salicylhydroxamic acidPaper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, Rutgers University, New Brunswick, N.J., USA