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Titolo:
Developmental changes in the NAD content in sugar-beet root mitochondria and their effect on the oxidative activity of these organelles
Autore:
Shugaev, AG;
Indirizzi:
Russian Acad Sci, KA Timiryazev Plant Physiol Inst, Moscow 127276, Russia Russian Acad Sci Moscow Russia 127276 hysiol Inst, Moscow 127276, Russia
Titolo Testata:
RUSSIAN JOURNAL OF PLANT PHYSIOLOGY
fascicolo: 5, volume: 48, anno: 2001,
pagine: 582 - 587
SICI:
1021-4437(200109/10)48:5<582:DCITNC>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
ISOLATED PLANT-MITOCHONDRIA; MALATE OXIDATION;
Keywords:
sugar beet; roots; ontogenesis; mitochondria; NAD;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
22
Recensione:
Indirizzi per estratti:
Indirizzo: Shugaev, AG Russian Acad Sci, KA Timiryazev Plant Physiol Inst, Botanicheskaya Ul 35, Moscow 127276, Russia Russian Acad Sci Botanicheskaya Ul 35 Moscow Russia 127276 ia
Citazione:
A.G. Shugaev, "Developmental changes in the NAD content in sugar-beet root mitochondria and their effect on the oxidative activity of these organelles", RUSS J PL P, 48(5), 2001, pp. 582-587

Abstract

The NAD content was determined in mitochondria isolated from sugar-beet roots at various stages of plant development. A high NAD content (7.6 +/- 0.9nmol/mg mitochondrial protein) was observed in the mitochondria of actively growing roots of 80-95-day-old plants, but it decreased ca. twofold by the end of the first year of plant development, before the roots were harvested for storage. The mitochondria isolated from roots stored at low temperature for two to three months and those after five to eight days of regrowth during the second year of plant development manifested an even lower NAD content (2.2 +/- 0.4 and 2.0 +/- 0.5 nmol/mg protein, respectively). A drastic decrease in the NAD content in mitochondria from stored roots did not result from the impairment of the inner membrane of these organelles and was evidently regulatory in its nature. The effect of developmental changes in the intramitochondrial NAD content on the malate oxidation pattern was studied. In the mitochondria of stored roots, the low NAD content limited the rate of malate oxidation in state 3, because the addition to the reaction mixture of exogenous NAD, which can be transported to the mitochondrial matrix, promoted malate oxidation by 30-50%. Rotenone inhibited malate oxidation in the stored-root mitochondria by more than 70%; in this case, the rate ofrotenone-resistant malate oxidation in these organelles increased by several times in the presence of exogenous NAD. In the mitochondria of the growing root, exogenous NAD did not affect the rate of malate oxidation, and rotenone inhibited it only by 25-35%. The analysis of the data obtained here and the published evidence suggests the existence of a universal mechanism of respiration control and the regulation of the functional activity of plant mitochondria. This mechanism acts through a change in the NAD content in the organelle matrix. This NAD can be used in the course of plant development, e.g., during the transition of sugar-beet-root cells in the dormant state, when the respiration rate must decline.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 23:58:38