Ionic currents and ion fluxes in Neurospora crassa hyphae

Autor:	Roger R. Lew
Rok vydání:	2007
Předmět:	Membrane potential Ion Transport Neurospora crassa biology Physiology Chemistry Voltage clamp Analytical chemistry Ionic bonding Plant Science biology.organism_classification Neurospora Ion Current clamp Botany Microelectrodes Ion-Selective Electrodes Ion transporter
Zdroj:	Journal of Experimental Botany. 58:3475-3481
ISSN:	1460-2431 0022-0957
Popis:	Voltage dependence of ionic currents and ion fluxes in a walled, turgor-regulating cell were measured in Neurospora crassa. The hyphal morphology of the model organism Neurospora simplifies cable analysis of ionic currents to determine current density for quantitative comparisons with ion fluxes. The ion fluxes were measured directly and non-invasively with self-referencing ion-selective microelectrodes. Four ions (H(+), Ca(2+), K(+), and Cl(-)) were examined. H(+) net uptake and Ca(2+) net release were small (10.2 nmol m(-2) s(-1) and 1.1 nmol m(-2) s(-1), respectively) and voltage independent. K(+) and Cl(-) fluxes were larger and voltage dependent. Maximal K(+) net release ( approximately 1440 nmol m(-2) s(-1)) was observed at positive voltages (+15 mV), while maximal Cl(-) net release ( approximately 905 nmol m(-2) s(-1)) was observed at negative voltage (-210 mV). A possible function of the net outward K(+) and Cl(-) fluxes is regulation of the plasma membrane potential. Total ion fluxes were 37-58% of the total ionic current density (about +/-244 mA m(-2), equivalent to +/-2500 nmol m(-2) s(-1), at 0 mV and -200 mV) so other ions must contribute significantly to the ionic currents.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7a5251e644c79e83261e8416d58113eb https://doi.org/10.1093/jxb/erm204 Zobrazit plný text záznamu