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Pak. J. Bot., 44(6): 1959-1964, 2012.

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FAILURE OF SURVIVAL STRATEGIES IN ADAPTION OF HEAVY METAL ENVIRONMENT IN LENS CULINARIS AND PHASEOLUS MUNGO

SABA HAIDER¹ AND RAFIA AZMAT^2*

Abstract: Lead (Pb)-treated Lens culinaris and Phaseolus mungo seedlings leaves showed considerable reduction in the size with enhance proline and phenol contents while peroxidase and lignin activity was Pb²⁺ dose dependent. The reduced leaves sizes of both seedlings were correlated with an increase in Pb²⁺ levels, and activities of peroxidase and lignin deposition in it. The intensification of activities of peroxidase and phenol in the Pb²⁺ treated plants were accompanied by an increase in the biosynthesis of the lignin contents as their function is of scavenging ROS radical. A strong correlation (r²=0.8570) was observed between Pb²⁺ and lignin deposition in the Lens culinaris whereas it was non-significant in Phaseolus mungo (r²=0.466). Increased in the lignin contents in the Lens culinaris as a chemical adaptation of the cell walls of various leaves tissues for endurance while decrease in the lignin contents in Phaseolus mungo at high dose of Pb²⁺may be attributed with the decline in the peroxidase activity. Investigations revealed that although plants adopt several biochemical strategies for their survival but toxicity of Pb²⁺was significant due to which plant fails to continue in stay alive.

¹Department of Botany, Jinnah University for Women 5C Nazimabad Karachi, 74600, Pakistan

²Department of Chemistry, University of Karachi, 75270, Pakistan.

^*Corresponding author e-mail: rafiasaeed200@yahoo.com