Studies in the Respiratory and Carbohydrate Metabolism of Plant Tissues2

Feeding strawberry and poplar leaves with iodoacetate, arsenite,or fluoride decreased the contents of sucrose and ascorbate.The content of hexose increased in high concentrations of iodoacetatebut decreased in moderate strengths. Iodo-acetate increasedthe rate of CO₂ output and caused a large decrease in phospholipidwith increase of inorganic phosphate. When iodoacetate was fedin nitrogen, CO₂ output did not increase. An explanation of the results is that the sucrose and ascorbateof the cell are mainly confined to the vacuole and that theabove poisons accelerate the leakage of these compounds fromthe vacuole so that they are metabolized more rapidly in thecytoplasm. An additional possibility is that iodoacetate ‘uncouples’oxidative phosphorylation, thereby stimulating respiration andmore rapid metabolism of both sucrose and ascorbate.