Response to cytosolic nickel of Slow Vacuolar channels in the hyperaccumulator plant Alyssum bertolonii.
We applied the patch-clamp technique to investigate the transport properties of the Slow Vacuolar (SV) channel identified in leaf vacuoles of Alyssum bertolonii Desv., a nickel hyperaccumulator plant growing in serpentine soil of the northern Apennines (Italy). SV currents recorded in vacuoles from adult plants collected in their natural habitat showed high sensitivity towards cytosolic nickel. Dose-response analyses indicated half-maximal current inhibition at submicromolar concentrations, i.e. up to three orders of magnitude lower than previously reported values from other plant species. The voltage-dependent increase of residual currents at saturating nickel concentrations could be interpreted as relief of channel block by nickel permeation at high positive membrane potentials. Including young plants of A. bertolonii into the study, we found that SV channels from these plants did not display elevated nickel sensitivity. This difference may be related to age-dependent changes in nickel hyperaccumulation of A. bertolonii leaf cells.
Corem
Shira
S
Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy.
Carpaneto
Armando
A
Soliani
Paolo
P
Cornara
Laura
L
Gambale
Franco
F
Scholz-Starke
Joachim
J
D019607:Brassicaceae / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism*; D008564:Membrane Potentials; D009532:Nickel / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D011523:Protoplasts / Q000378:metabolism; D013997:Time Factors; D014617:Vacuoles / Q000378:metabolism
D007473:Ion Channels; D010940:Plant Proteins; D009532:Nickel