Evaluating the invasive plant, Prosopis juliflora in the two initial growth stages as a potential candidate for heavy metal phytostabilization in metalliferous soil

ABSTRACT

Anthropogenic activities leads to increase in toxic metals in the environment. The toxicity of Cd, Cr and Pb to P. juliflora were tested in agar media; Seeds germinated in 25, 50 and 100 mg/L Pb; 5, 10 and 20 mg/ 10 L Cd; and 10 mg/L Cr were mostly unaffected. At 20 and 40 mg/L, Cr inhibited germination. Similarly, Cd and Cr treatments but not Pb disturbed seedlings development. Up to 3366.3 mg/kg and 1228.6 mg/kg of Pb accumulates in the root and shoot. The bioconcentration factor for both tissues ranged from 27.8 to 115.4 and 11.4 to 45.7, respectively. The translocation factor ranged from approximately 0.4 to 0.5, suggesting that it preferentially accumulates Pb in the root. Fourier Transformed Infrared Spectroscopy confirms Pb ions complexation with functional groups on the plant dry tissue biomass. These findings therefore, suggest that P. juliflora is suitable for Pb phytostabilization in metalliferous soil.

Abbreviations: ICP-OES: Inductively Coupled Plasma Optical Emission Spectrometry; FTIR: Fourier Transform Infrared Spectroscopy; BCF: Bioconcentration Factor; TF: Translocation Factor.

KEYWORDS:

• Prosopis juliflora
• lead accumulation
• phytoremediation
• germination
• bioconcentration factor

Future work

Most certainly, P. Juliflora exposure to Pb would have stimulated the accumulation of protein transporter molecules, which assisted in the metal uptake onto the plant tissues. However, their accumulation and performance may be optimal at a certain concentration of Pb than others. Therefore, as a future work, our group will study the effect of the different Pb concentrations on the accumulation of stress response proteins such as proline, and evaluate the activities of antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase (GR) and catalase.

Acknowledgments

The authors wish to acknowledge the Environmental Studies Center (ESC) and Central Laboratory Unit at Qatar University for providing support to ICP-OES and FTIR analysis, respectively. We would like to thank the office of research support at Qatar University’s for the student grant QUST-CAS-SPR-2017-33. We also wish to acknowledge Ms. Abeer Al-Muhannadi and Ms. Muneera Al-Mesaifri for their technical support in the Laboratory, as well as identification and collection of plants seeds. The publication of this article was funded by the Qatar National Library.

Competing interests

The authors declare no potential competing interests.

Disclosure statement

No potential conflict of interest was reported by the authors.