Effects of different sulfur compounds on the distribution characteristics of subcellular lead content in Arabis alpina L .var. parviflora Franch under lead stress

Sulfur plays a vital role in the phytoremediation of lead-contaminated soil. Effects of different sulfur forms (S0, Na2S, Na2SO4) on Pb absorption in hyperaccumulator Arabis alpina L. var. parviflora Franch were studied by soil culture pot experiment. The subcellular sulfur and lead enrichment characteristics in A. alpina were studied by adding sulfur in different forms and concentrations (0, 75, and 150 mg/kg) to Pb-contaminated soil. The results showed that the root and shoot biomass increased by 1.94 times under Na2S and Na2SO4 treatment, and the root-shoot ratio of A. alpine increased 1.62 times under three forms of sulfur treatments, compared with the control. Sulfur content in cell walls and soluble fractions of root and shoot of A. alpine significantly increased 3.35 ~ 5.75 times and decreased 5.85 and 9.28 times in the organelles under Na2SO4 treatment. Meanwhile, Pb content in the root and shoot cell walls of A. alpine significantly increased by 3.54 and 2.75 times, respectively. Pb content in the shoot soluble fraction significantly increased by 3.46 times, and the root organelle and soluble fraction significantly decreased by 2.72 and 2.46 times, respectively, while it significantly reduced by 3.78 times in the shoot organelle. Different forms and concentrations of sulfur had no regularity in the effect of Pb and sulfur content in the subcellular components of A. alpina, but the bioconcentration and translocation factors of A. alpina increased compared with the control. Under different concentrations of Na2SO4, there was a significant positive correlation between the contents of sulfur and Pb in the subcellular components of the root of A. alpina (P A. alpina by strengthening the cell wall fixation and compartmentalization of vacuoles.