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Titolo:
Membrane transport activity and ultradian ion flux oscillations associatedwith cell cycle of Thraustochytrium sp.
Autore:
Shabala, L; Shabala, S; Ross, T; McMeekin, T;
Indirizzi:
Univ Tasmania, Sch Agr Sci, Hobart, Tas 7001, Australia Univ Tasmania Hobart Tas Australia 7001 Sci, Hobart, Tas 7001, Australia
Titolo Testata:
AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY
fascicolo: 2, volume: 28, anno: 2001,
pagine: 87 - 99
SICI:
0310-7841(2001)28:2<87:MTAAUI>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUCLEAR MAGNETIC-RESONANCE; HYPHAL TIP GROWTH; ELONGATION REGION; INTRACELLULAR PH; PLASMA-MEMBRANE; DOCOSAHEXAENOIC ACID; CYTOSOLIC CALCIUM; CORN ROOTS; CA2+; AUREUM;
Keywords:
cell development; hydrogen; ion fluxes; membrane transport; sodium; ultradian oscillations;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
54
Recensione:
Indirizzi per estratti:
Indirizzo: Shabala, S Univ Tasmania, Sch Agr Sci, GPO Box 252-54, Hobart, Tas 7001, Australia Univ Tasmania GPO Box 252-54 Hobart Tas Australia 7001 ustralia
Citazione:
L. Shabala et al., "Membrane transport activity and ultradian ion flux oscillations associatedwith cell cycle of Thraustochytrium sp.", AUST J PLAN, 28(2), 2001, pp. 87-99

Abstract

Membrane transport activity associated with growth and nutritional status of a marine microheterotroph Thraustochytrium sp. was studied using non-invasive ion-selective slowly vibrating microelectrodes (the MIFE technique). Net fluxes of H+, Ca2+ and Na+ underwent regular changes as the cell progressed from the zoospore to sporangium stages of development. The most pronounced change was a decrease in the net H+ influx, which we suggest could be associated with the changes in cytoskeletal organization required for cell cleavage and zoospore release. As cell development progressed from the zoospore stage towards maturity, non-damping endogenous ultradian oscillations (period range of several minutes) became evident. At the sporangium stage, as many as 85% of cells possessed oscillatory membrane transport activity. It is suggested that ultradian ion flux oscillations in Thraustochytrium sp. may be causally linked with cell developmental processes. Discrete Fourier transform and cross-correlation analysis revealed a close association between oscillatory patterns of H+ and Na+ fluxes. The possibility that these oscillations result from the rhythmical activity of a Na+/H+ co-transporterlocated at the plasma membrane of Thraustochytrium sp. is considered. Oscillations in net Ca2+ flux were apparently not linked to those in H+ and Na+, and are believed to be due to some other physiological processes. Periodsof net H+ and Na+ flux oscillations were strongly dependent on the external Na+ concentrations in the bathing medium. As sodium is considered to be an essential element in Thraustochytrium sp., it is suggested that the functional role of such ultradian oscillations may be their involvement in the frequency-encoding mechanism that provides developing cells with informationabout environment, and nutritional status in particular.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/04/20 alle ore 14:20:34