a
Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, Hammam-lif, Tunisia
b Laboratoire des plantes aromatiques et médicinales, Centre de Biotechnologie de Borj-Cédria, BP 901, Hammam-lif, Tunisia
c Université de Rennes 1, UFR Sciences de la Vie et de l'Environnement UMR 118 INRA - Agrocampus Rennes Universite de Rennes 1,
b Laboratoire des plantes aromatiques et médicinales, Centre de Biotechnologie de Borj-Cédria, BP 901, Hammam-lif, Tunisia
c Université de Rennes 1, UFR Sciences de la Vie et de l'Environnement UMR 118 INRA - Agrocampus Rennes Universite de Rennes 1,
Abstract
Atriplex halimus is a
xerohalophyte plant, which could be used as cash crops. This plant was
integrated in Tunisian government programs the aim of which is to
rehabilitate saline areas and desert. To investigate its strategies
involved in salt tolerance, A. halimus was grown hydroponically under
controlled conditions with increasing salinity. Plants were harvested
and analyzed after 60 days of treatment. The biomass of A. halimus
increased by moderate salinity and decreased significantly at high
salinity compared to control plants at 400 mM. Despite of the large
amounts of Na+ observed in the leaves of Atriplex plants,
leaf water contents and leaf succulence kept on increasing in treated
plants and decreased over 150 mM NaCl. This confirmed the
compartmentation and the efficient contribution of Na+ in the
osmotic adjustment. Analysis of the metabolic profiles showed an
accumulation of carbohydrates and amino acids. The leaf tissues
preferentially stored proline, α alanine and sucrose. Increasing NaCl
levels were also accompanied by a significant accumulation of malate in
leaves. Involvement of these solutes in osmotic adjustment was
considered low. Nevertheless, they seemed to have an important role in
controlling photosynthesis which capacity was enhanced by low salinity
and decreased with increasing salinity (evaluated by actual
photochemical efficiency of photosystem II and chlorophyll contents).
The unchanged maximum photochemical efficiency of photosystem II
accompanied by the increase of the non-photochemical quenching, the
enhancement of the total antioxidant activity and the decrease of the
malondialdehyde contents in leaves showed efficient protection of
membranes and photosystem II from photo-oxidative damage. This
protection seemed to be attributed to proline and sucrose largely
accumulated in leaves treated with salt. © 2016 Elsevier Masson SAS.
Author keywords
Antioxidant activity; Atriplex halimus; Metabolites; Osmoprotection; Osmotic adjustment; Photosynthesis; Salinity
ISSN: 09819428
CODEN: PPBIESource Type: Journal
Original language: English
DOI: 10.1016/j.plaphy.2016.02.037Document Type: Article
Publisher: Elsevier Masson SAS
