Adequate S supply reduces the damage of high Cd exposure in roots and increases N, S and Mn uptake by Massai grass grown in hydroponics

Abstract

There are no studies showing the S effect on root development and nutrient uptake in forage grasses used for Cd phytoextraction. In this sense, our aim in this study was to evaluate in an integrated manner the effect of S supply (0.1, 1.9, and 3.7 mmol L-1) on root development and nutrient uptake of Panicum maximum Jacq. cv. Massai (Massai grass) exposed to Cd (0.1, and 0.5 mmol L-1), and the implications of this effect for Cd phytoextraction. Root development of Massai grass was strongly inhibited when plants were exposed to 0.5 mmol L-1 Cd, but adequate S supply (1.9 mmol L-1) allowed for higher Cd uptake. On the other hand, there was a greater development of roots when Massai grass was exposed to 0.1 mmol L-1 Cd, while some strategies to restrict Cd entry, such as deposition of suberin and lignin in the endodermis and G-layer development, were observed. Adequate supply of S to these plants increased root length, root surface, Cd transport from roots to stems + sheaths, and N, S, and Mn concentrations.