title: Comparative Ni tolerance and accumulation potentials between Mesembryanthemum crystallinum (halophyte) and Brassica juncea: Metal accumulation, nutrient status and photosynthetic activity.
abstract: Saline soils often constitute sites of accumulation of industrial and urban wastes contaminated by heavy metals. Halophytes, i.e. native salt-tolerant species, could be more suitable for heavy metal phytoextraction from saline areas than glycophytes, most frequently used so far. In the framework of this approach, we assess here the Ni phytoextraction potential in the halophyte Mesembryanthemum crystallinum compared with the model species Brassica juncea. Plants were hydroponically maintained for 21 days at 0, 25, 50, and 100μM NiCl2. Nickel addition significantly restricted the growth activity of both species, and to a higher extent in M. crystallinum, which did not, however, show Ni-related toxicity symptoms on leaves. Interestingly, photosynthesis activity, chlorophyll content and photosystem II integrity assessed by chlorophyll fluorescence were less impacted in Ni-treated M. crystallinum as compared to B. juncea. The plant mineral nutrition was differently affected by NiCl2 exposure depending on the element, the species investigated and even the organ. In both species, roots were the preferential sites of Ni(2+) accumulation, but the fraction translocated to shoots was higher in B. juncea than in M. crystallinum. The relatively good tolerance of M. crystallinum to Ni suggests that this halophyte species could be used in the phytoextraction of moderately polluted saline soils.
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors.forename: Taoufik
authors.initials: T
authors.lastname: Amari
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia. Electronic address: Tahar.ghnaya@gmail.com.
authors.forename: Tahar
authors.initials: T
authors.lastname: Ghnaya
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Debez
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors.forename: Manel
authors.initials: M
authors.lastname: Taamali
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors.forename: Nabil
authors.initials: N
authors.lastname: Ben Youssef
authors.affiliation: Department of Agricultural and Environmental Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lucchini
authors.affiliation: Department of Agricultural and Environmental Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
authors.forename: Gian Attilio
authors.initials: GA
authors.lastname: Sacchi
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors.forename: Chedly
authors.initials: C
authors.lastname: Abdelly
mesh_terms: D001673:Biodegradation, Environmental; D002734:Chlorophyll / Q000378:metabolism; D035723:Mesembryanthemum / Q000378:metabolism*; D008670:Metals / Q000378:metabolism; D009149:Mustard Plant / Q000378:metabolism*; D009532:Nickel / Q000378:metabolism*; D010788:Photosynthesis; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D018526:Plant Transpiration; D055051:Salt-Tolerant Plants; D012989:Soil Pollutants
chemical_list: D008670:Metals; D012989:Soil Pollutants; D002734:Chlorophyll; D009532:Nickel
keywords: Halophyte; Nickel; Photosynthesis; Phytoextraction; Tolerance