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Polyamines Interact with Hydroxyl Radicals in Activating Ca2+ and K+ Transport across the Root Epidermal Plasma Membranes 1[W]


Zepeda-Jazo, I and Velarde-Buendia, AM and Enriquez-Figueroa, R and Bose, J and Shabala, S and Muniz-Murguia, J and Pottosin, II, Polyamines Interact with Hydroxyl Radicals in Activating Ca2+ and K+ Transport across the Root Epidermal Plasma Membranes 1[W], Plant Physiology, 157, (4) pp. 2167-2180. ISSN 0032-0889 (2011) [Refereed Article]

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Copyright Statement

Copyright 2011 American Society of Plant Biologists

DOI: doi:10.1104/pp.111.179671


Reactive oxygen species (ROS) are integral components of the plant adaptive responses to environment. Importantly, ROS affect the intracellular Ca2+ dynamics by activating a range of nonselective Ca2+-permeable channels in plasma membrane (PM). Using patch-clamp and noninvasive microelectrode ion flux measuring techniques, we have characterized ionic currents and net K+ and Ca2+ fluxes induced by hydroxyl radicals (OH*) in pea (Pisum sativum) roots. OH*, but not hydrogen peroxide, activated a rapid Ca2+ efflux and a more slowly developing net Ca2+ influx concurrent with a net K+ efflux. In isolated protoplasts,OH* evoked a nonselective current, with a time course and a steady-state magnitude similar to those for a K+ efflux in intact roots. This current displayed a low ionic selectivity and was permeable to Ca2+. Active OH* -induced Ca2+ efflux in roots was suppressed by the PMCa2+ pump inhibitors eosine yellow and erythrosine B. The cation channel blockers gadolinium, nifedipine, and verapamil and the anionic channel blockers 5-nitro-2(3-phenylpropylamino)-benzoate and niflumate inhibited OH* -induced ionic currents in root protoplasts and K+ efflux and Ca2+ influx in roots. Contrary to expectations, polyamines (PAs) did not inhibit the OH* -induced cation fluxes. The net OH* -induced Ca2+ efflux was largely prolonged in the presence of spermine, and all PAs tested (spermine, spermidine, and putrescine) accelerated and augmented the OH* -induced net K+ efflux from roots. The latter effect was also observed in patch-clamp experiments on root protoplasts. We conclude that PAs interact with ROS to alter intracellular Ca2+ homeostasis by modulating both Ca2+ influx and efflux transport systems at the root cell PM.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Environmentally sustainable plant production
Objective Field:Environmentally sustainable plant production not elsewhere classified
UTAS Author:Bose, J (Dr Jayakumar Bose)
UTAS Author:Shabala, S (Professor Sergey Shabala)
UTAS Author:Pottosin, II (Professor Igor Pottosin)
ID Code:74021
Year Published:2011
Web of Science® Times Cited:116
Deposited By:Agricultural Science
Deposited On:2011-11-08
Last Modified:2012-08-01

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