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Salinity effects on chloroplast PSII performance in glycophytes and halophytes

Citation

Percey, WJ and McMinn, A and Bose, J and Breadmore, MC and Guijt, RM and Shabala, S, Salinity effects on chloroplast PSII performance in glycophytes and halophytes, Functional Plant Biology, 43, (11) pp. 1003-1015. ISSN 1445-4408 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 CSIRO

DOI: doi:10.1071/FP16135

Abstract

The effects of NaCl stress and K+ nutrition on photosynthetic parameters of isolated chloroplasts were investigated using PAM fluorescence. Intact mesophyll cells were able to maintain optimal photosynthetic performance when exposed to salinity for more than 24†h whereas isolated chloroplasts showed declines in both the relative electron transport rate (rETR) and the maximal photochemical efficiency of PSII (Fv/Fm) within the first hour of treatment. The rETR was much more sensitive to salt stress compared with Fv/Fm, with 40% inhibition of rETR observed at apoplastic NaCl concentration as low as 20†mM. In isolated chloroplasts, absolute K+ concentrations were more essential for the maintenance of the optimal photochemical performance (Fv/Fm values) rather than sodium concentrations per se. Chloroplasts from halophyte species of quinoa (Chenopodium quinoa Willd.) and pigface (Carpobrotus rosii (Haw.) Schwantes) showed less than 18% decline in Fv/Fm under salinity, whereas the Fv/Fm decline in chloroplasts from glycophyte pea (Pisum sativum L.) and bean (Vicia faba L.) species was much stronger (31 and 47% respectively). Vanadate (a P-type ATPase inhibitor) significantly reduced Fv/Fm in both control and salinity treated chloroplasts (by 7 and 25% respectively), whereas no significant effects of gadolinium (blocker of non-selective cation channels) were observed in salt-treated chloroplasts. Tetraethyl ammonium (TEA) (K+ channel inhibitor) and amiloride (inhibitor of the Na+/H+ antiporter) increased the Fv/Fm of salinity treated chloroplasts by 16 and 17% respectively. These results suggest that chloroplastsí ability to regulate ion transport across the envelope and thylakoid membranes play a critical role in leaf photosynthetic performance under salinity.

Item Details

Item Type:Refereed Article
Keywords:photosynthesis, potassium, sodium, ROS, membrane transport
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Environment
Objective Group:Control of Pests, Diseases and Exotic Species
Objective Field:Control of Animal Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments
Author:Percey, WJ (Mr William Percey)
Author:McMinn, A (Professor Andrew McMinn)
Author:Bose, J (Dr Jayakumar Bose)
Author:Breadmore, MC (Professor Michael Breadmore)
Author:Guijt, RM (Dr Rosanne Guijt)
Author:Shabala, S (Professor Sergey Shabala)
ID Code:113147
Year Published:2016
Web of Science® Times Cited:1
Deposited By:Centre for Ecology and Biodiversity
Deposited On:2016-12-14
Last Modified:2017-04-10
Downloads:0

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