Synergism between polyamines and ROS in the induction of Ca ( 2+)  and K (+)  fluxes in roots.
Stress conditions cause increases in ROS and polyamines levels, which are not merely collateral. There is increasing evidence for the ROS participation in signaling as well as for polyamine protective roles under stress. Polyamines and ROS, respectively, inhibit cation channels and induce novel cation conductance in the plasma membrane. Our new results indicate that polyamines and OH (•)  also stimulate Ca ( 2+)  pumping across the root plasma membrane. Besides, polyamines potentiate the OH (•) -induced non-selective current and respective passive K (+)  and Ca ( 2+)  fluxes. In roots this synergism, however, is restricted to the mature zone, whereas in the distal elongation zone only the Ca ( 2+)  pump activation is observed. Remodeling the plasma membrane ion conductance by OH (•)  and polyamines would impact K (+)  homeostasis and Ca ( 2+)  signaling under stress.
Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, México. pottosin@ucol.mx
Igor
I
Pottosin
Ana-María
AM
Velarde-Buendía
Isaac
I
Zepeda-Jazo
Oxana
O
Dobrovinskaya
Sergey
S
Shabala
D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006706:Homeostasis; D006878:Hydroxides / Q000378:metabolism; D018532:Pisum sativum / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D011073:Polyamines / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D013312:Stress, Physiological
D015220:Calcium Channels; D006878:Hydroxides; D011073:Polyamines; D017382:Reactive Oxygen Species; C031356:hydroxide ion; D011188:Potassium; D002118:Calcium