Interactions entre mitochondries et chloroplastes dans la cellule. II. Action du DBMIB, de l'antimycine A et du FCCP sur la spore de Funaria hygrometrica

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Abstract
The effect of DBMIB [2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone], antimycin A, and FCCP [carbonyl cyanide p-trifluoromethoxyphenylhydrazone] on respiration and photosynthesis of intact chlorophyllic moss (F. hygrometrica) spore was investigated. Antimycin A (1 .mu.M) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values) and stimulated photosynthesis at low light intensities (below the saturation plateau values). DBMIB (3 .mu.M) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 .mu.M) partially inhibited O2 production at high light intensities. The inhibition observed was partially relieved by 1 .mu.M antimycin A or 30 .mu.M KCN; higher concentration of FCCP totally inhibited the O2 production. In the chlorophyllic moss spore, the cytochrome oxidase pathway may not function under high light intensities, and this inhibition of respiration may be attributable to the low cytoplasmic ADP:ATP ratio.