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Faba bean (Vicia faba L.) seeds were treated with H2O [nonprimed (NP)] or 2% CaCl2 [primed (P)] before germination for 6 h. After seven days, seedlings were exposed to 0 or 50 µM CdCl2 concentrations for three weeks. Under Cd treatment, P plants showed an improvement of gas-exchange characteristics, chlorophyll (Chl) and carotenoids contents as compared to NP plants subjected to Cd stress. Additionally, the values of Chl fluorescence were relatively similar to those of control, implying that no photodamage occurred. Moreover, under 50 µM Cd, the P plants exhibited lesser accumulation of hydrogen peroxide and superoxide radicals in leaves as compared to NP plants. Likewise, results showed that CaCl2seed pretreatment alleviated adverse effects of Cd on electrolyte leakage. In conclusion, CaCl2 improved photosynthesis attributes of faba bean plants subjected to Cd stress by mitigating the adverse effects of Cd toxicity through a reduced generation of reactive oxygen species.Additional key words: nonphotochemical quenching; photosynthetic apparatus; seed priming; water-use efficiency. electron transport rate; F0 -minimal chlorophyll fluorescence; FM -fresh mass; Fm -maximal chlorophyll fluorescence; Fm' -maximal fluorescence yield of the light-adapted state; Fs -steady-state fluorescence yield; Fv -variable chlorophyll fluorescence; Fv/Fm -maximum photochemical quantum efficiency of PSII; gs − stomatal conductance; NPQ -nonphotochemical quenching; PN -net CO2 assimilation rate; ROS -reactive oxygen species; SE -standard error; WUE -intrinsic water-use efficiency (PN/gs); ФPSII -actual PSII efficiency. Acknowledgements: The authors are grateful for the financial support provided by the Tunisian Ministry of Higher Education and Scientific Research.

Literature on the separate effects of salinity and inadequate Fe supply on plant growth and nutrient uptake, concentration, and distribution is abundant but little is known about the interactive effects of these two abiotic constraints. Here, we investigated the interactive effect of iron availability and salinity on physiological responses of cultivated and wild barley (Hordeum vulgare and H. maritimum resp.). Seedlings of both species were grown for 9 days, under complete nutrient solution with or without iron supply. Then, NaCl treatment was applied at different concentrations (0, 100, 200, and 300 mM) for 60 hours. After salt exposure, shoot water content of H. vulgare was significantly reduced as compared to H. maritimum. Furthermore, Na + accumulation in shoots increased parallel to increasing NaCl concentration in the medium. However, the increase was significantly higher in H. vulgare than in H. maritimum. These responses were associated with lower Fe absorption efficiency photosynthetic parameters in both species. The reduction was significantly higher in cultivated than in wild barley. Moreover, phytosiderophore exudation was enhanced in both species by direct (iron free medium) or indirect iron limitation (salt-induced iron limitation). Such a stimulation of phytosiderophore release was genotype and salt level dependant.

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