Mitigation mechanism of zinc oxide nanoparticles on cadmium toxicity in tomato

Liangliang Sun; Ruting Wang; Qiong Ju; Menglu Xing; Ruishan Li; Weimin Li; Wen Li; Wenying Wang; Yanfang Deng; Jin Xu

doi:10.3389/fpls.2023.1162372

Mitigation mechanism of zinc oxide nanoparticles on cadmium toxicity in tomato

Front Plant Sci. 2023 Mar 27:14:1162372. doi: 10.3389/fpls.2023.1162372. eCollection 2023.

Authors

Liangliang Sun¹, Ruting Wang¹, Qiong Ju¹, Menglu Xing¹, Ruishan Li¹, Weimin Li¹, Wen Li¹, Wenying Wang², Yanfang Deng³, Jin Xu¹

Affiliations

¹ College of Horticulture, Shanxi Agricultural University, Taigu, China.
² College of Life Science, Qinghai Normal University, Xining, China.
³ Qinghai Service and Guarantee Center of Qilian Mountains National Park, Xining, China.

Abstract

Cadmium (Cd) pollution seriously reduces the yield and quality of vegetables. Reducing Cd accumulation in vegetables is of great significance for improving food safety and sustainable agricultural development. Here, using tomato as the material, we analyzed the effect of foliar spraying with zinc oxide nanoparticles (ZnO NPs) on Cd accumulation and tolerance in tomato seedlings. Foliar spraying with ZnO NPs improved Cd tolerance by increasing photosynthesis efficiency and antioxidative capacity, while it reduced Cd accumulation by 40.2% in roots and 34.5% in leaves but increased Zn content by 33.9% in roots and 78.6% in leaves. Foliar spraying with ZnO NPs also increased the contents of copper (Cu) and manganese (Mn) in the leaves of Cd-treated tomato seedlings. Subsequent metabonomic analysis showed that ZnO NPs exposure alleviated the fluctuation of metabolic profiling in response to Cd toxicity, and it had a more prominent effect in leaves than in roots. Correlation analysis revealed that several differentially accumulated metabolites were positively or negatively correlated with the growth parameters and physiol-biochemical indexes. We also found that flavonoids and alkaloid metabolites may play an important role in ZnO NP-alleviated Cd toxicity in tomato seedlings. Taken together, the results of this study indicated that foliar spraying with ZnO NPs effectively reduced Cd accumulation in tomato seedlings; moreover, it also reduced oxidative damage, improved the absorption of trace elements, and reduced the metabolic fluctuation caused by Cd toxicity, thus alleviating Cd-induced growth inhibition in tomato seedlings. This study will enable us to better understand how ZnO NPs regulate plant growth and development and provide new insights into the use of ZnO NPs for improving growth and reducing Cd accumulation in vegetables.

Keywords: ZnO nanoparticles; alkaloids; amino acids; cadmium accumulation; cadmium stress; flavonoids.

Grants and funding

This research was supported by the Basic Research Program of Shanxi Province (Free Exploration) (20210302124369), the Innovation Project for graduate students in Shanxi Province (2021Y307), the investigation and monitoring of typical forest, shrub, and meadow ecosystems in the vertical distribution zone of the Haibei region of the National Park (QHXH-2021-017), and the Science and Technology Innovation Fund project of Shanxi Agricultural University (2020QC13 and 2020BQ24).