Phytoaccumulation of zinc from contaminated soil using ornamental plants species Helianthus annuus L. and Tagetes erecta L.

Abstract

Intensive research on hyperaccumulator plant species provides an alternative method to cleanup heavy metal contaminated sites using these plants. Helianthus annuus and Tagetes erecta are suitable hyperaccumulator plant species for removing zinc (Zn) from contaminated soil because of their high phytoremediation effectiveness. The present study focused on to evaluate comparative efficacy of Zn accumulation using H. annuus and T. erecta. Plantlets were exposed to different Zn concentrations (10, 50, 100, 300, and 500 mg kg⁻¹) for 20, 40, and 60 days while changes in morphological, biochemical, and enzyme activity markers were evaluated. The concentration of Zn in various plant parts was determined using an atomic absorption spectrophotometer (AAS). After 60 days H. annuus showed greatest accumulation of Zn in the root and shoot (216.7 and 109.5 mg kg⁻¹), whereas the Zn accumulation T. erecta (209.5 and 97.84 mg kg⁻¹) was found comparatively less in the root and shoot. The result showed increased polyphenol and proline concentrations with increasing Zn concentrations which were maximal in H. annuus 6.642 mg g⁻¹ and 25.474 µmol g⁻¹, respectively. At 60 days, APX (4.145 mM mg⁻¹), CAT (2.558 mM mg⁻¹), and GR (52.23 mM mg⁻¹) antioxidant enzymatic activities were observed with higher concentrations. Analysis of ultrastructure confirmed Zn transport and localization in root and shoot tissues examined through FESEM-EDX, Fluorescence microscopy, and optical microscopy. The present research findings concluded with the high amount of removal of Zn from contaminated soil using H. annuus and T. erecta for ecofriendly approach to soil cleanup followed by sustainable agriculture.

Graphical Abstract

NOVELTY STATEMENT

Our research work focused on the removal of zinc from the contaminated soil by phytoremediation using ornamental plants species Helianthus annuus and Tagetes erecta. Our research findings through detailed microscopic observation, antioxidant analysis, and biochemical evaluation have proven that Helianthus annuus L. have a better capability for Zn mitigation in the contaminated site as compared to Tagetes erecta. As an outcome of this research, we authentically suggest for use of H. annuus as a good accumulator of Zn compared to T. erecta.

Keywords:

• Helianthus annuus
• hyperaccumulator plants
• microscopic analysis
• phytoremediation
• Tagetes erecta
• zinc

Acknowledgments

The authors would like to express their appreciation to honorable Prof. Ina Aditya Shastri Vice-Chancellor, Banasthali Vidyapith and Prof. Dipjyoti Chakraborty, Head of the Department of Bioscience and Biotechnology, Banasthali Vidyapith, for providing lab facility and other support to carry out present research work. Additionally, we are thankful to DST for providing instrumentation support of atomic absorption spectrophotometer.

Consent for publication

The authors have consent for publication.

Author contributions

JM and MS were the ones that came up with the concept of authoring the study and created the content. JM promoted the investigation and oversaw the findings. MS carried out the experiments. JM and MS both helped with the data analysis and manuscript compilation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated or analyzed during this study are included in this article.