Polyamines prevent NaCl-induced K+ efflux from pea mesophyll by blocking non-selective cation channels.
Despite numerous reports implicating polyamines in plant salinity responses, the specific ionic mechanisms of polyamine-mediated adaptation to salt-stress remain elusive. In this work, we show that micromolar concentrations of polyamines are efficient in preventing NaCl-induced K(+) efflux from the leaf mesophyll, and that this effect can be attributed to the inhibition of non-selective cation channels in mesophyll. The inhibition by externally applied polyamines developed slowly over time, suggesting a cytosolic mode of action. Overall, we suggest that elevated levels of cellular polyamine may modulate the activity of plasma membrane ion channels, improving ionic relations and assisting in a plant's adaptation to salinity.
Shabala
Sergey
S
School of Agricultural Science, University of Tasmania, Hobart, Tas 7001, Australia. Sergey.Shabala@utas.edu.au
Cuin
Tracey A
TA
Pottosin
Igor
I
D015640:Ion Channel Gating / Q000187:drug effects*; D007473:Ion Channels / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D018532:Pisum sativum / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D011073:Polyamines / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*
D007473:Ion Channels; D011073:Polyamines; D012965:Sodium Chloride; D011188:Potassium