Mechanisms of Potassium Transport in Plants and Fungi . Progress Report

Download or read book Mechanisms of Potassium Transport in Plants and Fungi . Progress Report written by and published by . This book was released on 1993 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress is reported on three front namely survey of ion channels in Arabidopsis; chemical characterization of the tonoplast cation channel (YVC1) in Saccharomyces; and characterization of a fungal proton pump cloned into mammalian cells. Continued work with the yeast plasma-membrane K channel (YPK1) led to clear demonstrations that gating of YPK1 depends upon the disequilibrium voltage for K, rather than upon the absolute membrane voltage, and that all channels observable in the yeast plasmalemma are unchanged in primary pump mutants. Preliminary patch-clamp studies on the plasmalemma of Neurospora also identified two conspicuous cation channels in that membrane. A concerted effort to measure cytoplasmic pH in Saccharomyces and Neurospora by means of fluorescent pH indicators evinced two important findings that dyes taken up in (lipophilic) heavily esterified forms accumulate in vacuoles, not in the cytosol; and that the size and distribution of fungal vacuoles can be manipulated dramatically by altering carbon metabolism.