Application of glutathione and dithiothreitol to oil seed rape (Brassica napus L.) roots affects cadmium distribution in roots and inhibits Cd translocation to shoots
Previously we have shown that site-specific application of glutathione (GSH) to roots inhibits cadmium (Cd) translocation from roots to shoots. In this study, we investigated the effects of chemical compounds containing sulfur, such as dithiothreitol (DTT), potassium sulfate (K2SO4) and a GSH synthesis inhibitor, buthionine sulfoximine (BSO), on the behavior of Cd in oilseed rape plants (Brassica napus L.). We found that DTT, just like GSH, also inhibited Cd translocation from roots to shoots significantly. However, the inhibitory effects of Cd behaviors differed between GSH and DTT. Cd efflux from root cells was activated by GSH and inactivated by DTT. Positron imaging experiments revealed that there are minor differences in the effects of GSH and DTT on Cd adsorption to the surface of roots. These results provide insights into the function of GSH involved in the inhibitory effects of Cd translocation from roots to shoots.