Expression of metal transporting (HMA2, HMA4) in Brassica juncea and Brassica nigra species grown at different Zn levels

Brassica juncea (brown mustard) and Brassica nigra (black mustard) are land plants with a well-known root system that accumulate certain heavy metals. In this study, B. juncea and B. nigra plants were grown at different ZnSO4 concentrations for 15 days. With the application of Zn, the metal accumulation capacities in the root and leaves of these plant species were studied. Gene expression of metal ATPases (HMA2, HMA4) in Brassica species (B. nigra B. juncea) grown at different Zn levels were analyzed by using Real Time PCR. In all these data, the amount of Zn accumulation in the roots of B. juncea was not significant. In contrast, B. juncea accumulated more Zn in roots compare to B. nigra roots. The amount of Zn accumulation in the leaves of both plant species was more or less similar. In addition, the expression pattern of HMA4 and HMA2 genes in B. juncea (Zn) and B. nigra (Zn) was found to be similar to the glutathione amount in the leaves. As a result,both plant species were found to be good candidates for phytoremediation of Zn. Key words: B. juncea, B. nigra, Heavy metal ATPases (HMA2, HMA4), Gene expression, Phytoremediation