Comparison of effect of CdS QD and ZnS QD and their corresponding salts on growth, chlorophyll content and antioxidative capacity of tomato

Abstract

When applied in the same concentration to tomato plants, cadmium sulfate (CdSO₄₎ and zinc sulfate (ZnSO₄) were transported from soil to roots and from roots to shoots more readily than their nano counterparts: cadmium sulfide quantum dots (CdS QD) and zinc sulfide quantum dots (ZnS QD). Compared to the CdS QD, he higher rate of transport of CdSO₄ resulted in a greater negative effect on growth, chlorophyll content, antioxidant properties, lipid peroxidation and activation of antioxidant defence systems. Although ZnSO₄ was transported more rapidly than ZnS QD, the overall effect of Zn addition was positive (increase in total plant mass, stem length, antioxidant content and decrease in lipid peroxidation). However, these effects were more pronounced in the case of ZnS QD, suggesting that the mechanisms underpinning the activity of ZnS QD and ZnSO₄ were different. Thus, the risk of phytotoxicity and food chain transfer of the two elements depended on their form (salt or nanoform), and consequently their effects on plants’ growth and physiology were different.

NOVELTY STATEMENT

This work elucidates the mechanisms underlying the responses of CdS QD and ZnS QD in contrast to those of their corresponding salts on tomato plants. Our results showed that faster transport from roots to leaves in the case of salts in respect to the nanoform augment their detrimental impact on tomato’s antioxidant properties and growth and make the nanoform of both a better alternative for crop application either as fertilizers or as pesticides.

Keywords:

• Cadmium
• nanoparticles
• photosynthesis
• transport
• zinc

Acknowledgments

The Authors would like to acknowledge Professor Brett Robinson (Soil Chemistry) of Canterbury University, New Zealand, for helping in revising the manuscript.

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

This work was funded by under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.5 - Call for tender No. 3277 of 30-12-2021 of Italian Ministry of University and Research funded by the European Union – Next Generation EU; Award Number: Project code: ECS_00000033, Concession Decree No. 0001052 of 23/06/2022 adopted by the Italian Ministry of University and Research, CUP: B89I22000650001, Project title: “Ecosystem for sustainable transition in Emilia Romagna”.