Antioxidant system response, mineral element uptake and safe utilization of Polygonatum sibiricum in cadmium-contaminated soil

Yuchen Kang,Li Yang,Haibo Dai,Wenqing Chen,Jie Peng,Mengdi Xie,Tianqi Ao,Hui Sun,Yuhao Wang

doi:10.1038/s41598-021-97998-7

Abstract

Chinese herbal medicine is widely cultivated in Southwest China, where the soil cadmium (Cd) contamination of farmland is more serious than that in China as a whole. In this study, Polygonatum sibiricum was exposed to Cd at concentrations of e−1, e0, e2, and e4 mg/kg for 30, 60, and 90 days, and the physiological stress responses, Cd and mineral element uptake, antioxidant enzyme activities, and content changes of pharmaceutical ingredients (polysaccharides) were analyzed to decipher the feasibility of safe utilization in Cd-contaminated soil. The results show that the activity of antioxidant enzymes (SOD and CAT) in the aboveground part was always higher than that in the underground part. The underground part of Polygonatum sibiricum mobilizes nonenzymatic systems to facilitate the synthesis of polysaccharides (PCP1, PCP2) with antioxidant properties to cope with Cd stress. Mineral elements (P, K, Ca, Mg, Fe, Cu, and Zn) significantly (p < 0.05) changed after 90 d of cultivation. In particular, the changes in the iron and zinc content were significantly correlated (p < 0.05) with the activities of SOD and POD. Soil Cd at e0 mg/kg can guarantee the safe production and utilization of Polygonatum sibiricum, and the stimulation of Cd promotes polysaccharide synthesis and biomass growth.

Highlights

Chinese herbal medicine is widely cultivated in Southwest China, where the soil cadmium (Cd) contamination of farmland is more serious than that in China as a whole
In preliminary s tudies[9], we found that the Chinese herbal medicine Polygonatum sibiricum has the characteristic of low accumulation of Cd, and because it is rich in polysaccharides and other medicinal active components, it has a high added value and is advantageous for safe cultivation of Cd-contaminated soil
The experiments were conducted with soil medium, and the Polygonatum sibiricum was grown in 35 cm × 35 cm × 20 cm wooden pots, each with a soil mass of 15 kg

Summary

Introduction

Chinese herbal medicine is widely cultivated in Southwest China, where the soil cadmium (Cd) contamination of farmland is more serious than that in China as a whole. Polygonatum sibiricum was exposed to Cd at concentrations of e−1, e0, e2, and e4 mg/kg for 30, 60, and 90 days, and the physiological stress responses, Cd and mineral element uptake, antioxidant enzyme activities, and content changes of pharmaceutical ingredients (polysaccharides) were analyzed to decipher the feasibility of safe utilization in Cd-contaminated soil. In preliminary s tudies[9], we found that the Chinese herbal medicine Polygonatum sibiricum has the characteristic of low accumulation of Cd, and because it is rich in polysaccharides and other medicinal active components, it has a high added value and is advantageous for safe cultivation of Cd-contaminated soil. John’s wort completely lose the ability to synthesize or accumulate hyperforin, and the concentrations of pseudohypericin and hypericin demonstrate a 15- to 20-fold decrease[23]

Methods

Results

Conclusion