The response of a model C3/CAM intermediate semi-halophyte Mesembryanthemum crystallinum L. to elevated cadmium concentrations
Michał Nosek , Adriana Kaczmarczyk , Marta Śliwa , Roman Jędrzejczyk , Andrzej Kornas , Paulina Supel , Paweł Kaszycki , Zbigniew Miszalski
AbstractMany areas exhibiting increased concentrations of soluble salts are simultaneously polluted with heavy metals (HM), and halophytes with extended tolerance to heavy metal toxicity seem to represent a promising tool for their phytoremediation. In this study, the response of the soil-grown C3-CAM (Crassulacean acid metabolism) intermediate halophyte Mesembryanthemum crystallinum (common ice plant) to increased concentrations of Cd (0.01–1 mM) was investigated. None of the tested Cd treatments affected growth parameters or tissue water content of either C3 or CAM-performing plants. Chlorophyll a fluorescence confirmed high tolerance of the photosynthetic apparatus of both metabolic states towards Cd. Plants performing both photosynthesis types accumulated significant Cd amounts only under the highest (1 mM) treatment, and the metal was primarily deposited in the roots, which are features typical of an excluding strategy. Upon the application of 1 mM Cd solution CAM-performing plants, due to the NaCl pre-treatment applied for CAM induction, were exposed to significantly higher amounts of bioavailable Cd in comparison with those of C3-performing plants. As a result, roots of CAM plants accumulated over 4-fold higher Cd amounts when compared with C3 plants. In our opinion, enhanced Cd-accumulating potential observed in CAM-performing plants was the effect of osmotic stress episode and resulting modifications e.g. in the detoxifying capacity of the antioxidative system. Increased antioxidative potential of NaCl pre-treated plants was pronounced with significantly higher activity of CuZnSOD (copper-zinc superoxide dismutase), not achievable in C3 plants subjected to high Cd concentrations. Moreover, the applied Cd doses induced SOD activity in a compartment-dependent manner only in C3 plants. We confirmed that none of the applied Cd concentrations initiated the metabolic shift from C3 to CAM.
|Journal series||Journal of Plant Physiology, ISSN 0176-1617, e-ISSN 1618-1328, (N/A 100 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Heavy metal stress, Ice plant, Photosynthetic metabolism, Phytoremediation, SOD, Soil-grown|
|ASJC Classification||; ;|
|Publication indicators||= 0; : 2018 = 1.174; : 2018 = 2.825 (2) - 2018=3.236 (5)|
|Finansowanie||This study was funded with the National Science Centre (Poland), "OPUS" project number 2016/21/B/NZ9/00813.|
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