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Hydroxyl radical scavenging by cerium oxide nanoparticles improves Arabidopsis salinity tolerance by enhancing leaf mesophyll potassium retention


Wu, H and Shabala, L and Shabala, S and Giraldo, JP, Hydroxyl radical scavenging by cerium oxide nanoparticles improves Arabidopsis salinity tolerance by enhancing leaf mesophyll potassium retention, Environmental Science: Nano, 5 pp. 1567-1583. ISSN 2051-8153 (2018) [Refereed Article]

Copyright Statement

Copyright 2018 The Royal Society of Chemistry

DOI: doi:10.1039/c8en00323h


Salinity is a widespread environmental stress that severely limits crop yield worldwide. Cerium oxide nanoparticles (nanoceria) have the unique capability of catalytically reducing levels of stress-induced reactive oxygen species (ROS) including hydroxyl radicals (˙OH) that lack enzymatic scavenging pathways. The underlying mechanisms of how nanoceria ROS scavenging augments plant tolerance to environmental stress are not well understood. Herein, we demonstrate that catalytic ˙OH scavenging by nanoceria in Arabidopsis thaliana leaves significantly improves mesophyll K+ retention, a key trait associated with salinity stress tolerance. Leaves with mesophyll cells interfaced with 50 mg L−1 polyIJacrylic acid) coated nanoceria (PNC) have significantly higher (P < 0.05) carbon assimilation rates (85%), quantum efficiency of photosystem II (9%), and chlorophyll content (14%) compared to controls after being exposed to 100 mM NaCl for 3 days. PNC infiltrated leaves (PNC-leaves) under salinity stress exhibit lower ROS levels including hydroxyl radical (41%) and its precursor hydrogen peroxide (44%) and one fold higher (P < 0.05) cytosolic K+ dye intensity in leaf mesophyll cells relative to controls. Non-invasive microelectrode ion flux electrophysiological (MIFE) measurements indicated that PNC-leaves have about three-fold lower NaCl-induced K+ efflux from leaf mesophyll cells compared to controls upon exposure to salinity stress. The ROS-activated nonselective cation channels (ROS-NSCC) in the plasma membrane of leaf mesophyll cells were identified as the main ˙OH-inducible K+ efflux channels. Long term catalytic scavenging of ˙OH in leaves by PNC enhances plant photosynthetic performance under salinity stress by enabling plasma membrane channels/transporters to coordinately retain higher levels of K+ in the leaf mesophyll cell cytosol. PNC augmented plant ROS scavenging provides a key tool for understanding and improving plant tolerance against abiotic stresses such as salinity.

Item Details

Item Type:Refereed Article
Keywords:potassium, salinity, mesophyll, ion channels
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Shabala, S (Professor Sergey Shabala)
ID Code:127311
Year Published:2018
Web of Science® Times Cited:115
Deposited By:Agriculture and Food Systems
Deposited On:2018-07-20
Last Modified:2019-03-05

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