The response of a model C3/CAM intermediate semi-halophyte Mesembryanthemum crystallinum L. to elevated cadmium concentrations.
J Plant Physiol
; 240: 153005, 2019 Sep.
Article
en En
| MEDLINE
| ID: mdl-31271976
ABSTRACT
Many 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 (0.01-1â¯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 (1â¯mM) treatment, and the metal was primarily deposited in the roots, which are features typical of an excluding strategy. Upon the application of 1â¯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.
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Banco de datos:
MEDLINE
Asunto principal:
Contaminantes del Suelo
/
Cadmio
/
Mesembryanthemum
/
Plantas Tolerantes a la Sal
Idioma:
En
Año:
2019
Tipo del documento:
Article