Salicylate-collapsed membrane potential in pea stem mitochondria |
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| Authors: | Francesco Macri Angelo Vianello Sergio Pennazio |
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| Affiliation: | Inst. of Plant Biosynthesis, Section of Padova, C.N.R., C.so Stalti Vniti 4, I-35020 Padova, Italy and Inst. of Plant Protection, Univ. of Udine, P. le Kolbe 4, I-33100 Udine, Italy;Inst. of Applied Plant Virology, C.N.R., Via Vigliani 104, I-10135 Torino, Italy. |
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| Abstract: | Salicylate, acetylsalicylate, benzoate and 3,5-diiodosalicylate were examined for their effects on pea ( Pisum sativum L. cv. Alaska) stem mitochondria and on a tonoplast-enriched fraction. Salicylate collapsed the transmembrane electrochemical potential of mitochondria and the ATP-dependent proton gradient of the tonoplast-enriched vesicle preparation. Benzoate and acetylsalicylate did not show any effect, while 3,5-diiodosalicylate inhibited both basal O2 consumption and ATPase activity of pea mitochondria. Salicylate seems to act as a protonophore. However, its effect is evident only at concentrations higher than those required by classical protonophores and, in addition, can be abolished after removing salicylate from the incubation medium. The activity of salicylate appears linked to the presence of the free phenolic hydroxyl on the benzene ring. |
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| Keywords: | Acridine orange ATPase phenolic acids tonoplast-enriched membranes TPP+ electrode |
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