Uranium(VI) toxicity in tobacco BY-2 cell suspension culture - a physiological study


Uranium(VI) toxicity in tobacco BY-2 cell suspension culture - a physiological study

Rajabi, F.; Jessat, J.; Garimella, J. N.; Bok, F.; Steudtner, R.; Stumpf, T.; Sachs, S.

For the first time, the physiological and cellular responses of Nicotiana tabacum (BY-2) cells to uranium (U) as an abiotic stressor was studied in a multi analytic approach combining biochemical analysis, thermodynamic modeling and spectroscopic studies. It was focused on the determination of the U threshold toxicity in tobacco BY-2 cells, the influence of U on the homeostasis of micro-macro essential nutrients as well as the effect of Fe starvation on U bioassociation in cultured BY-2 cells. Our findings showed that U interferes with the homeostasis of essential elements. The interaction of U with BY-2 cells showed a time and concentration dependent kinetic. Under Fe deficiency, less U was detected in the cells compared to Fe sufficient conditions. Interestingly, blocking of Ca channels by gadolinium chloride caused a decrease in U concentration in BY-2 cells. Spectroscopic studies evidenced changes in the U speciation in the culture media with increasing exposure time under Fe sufficient and deficient conditions. Thusly, different stress response reactions related to the Fe metabolism are assumed. It is suggested that U toxicity in BY-2 cells is highly dependent on the existence of other micro-macro elements as showed by negative synergistic effects of U and Fe on the viability of cells.

Keywords: Nicotiana tabacum cells; uranium; toxicity; physiology; bioavailability; Fe starvation; speciation; plants; plant cells

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Publ.-Id: 31343