Understanding Biochemical Defense of Leucas Aspera in Crude Oil Polluted Habitat and Changes in Soil Properties

Abstract

The response of an indigenous medicinal herb Leucas aspera in crude oil polluted habitat was studied. The productivity, antioxidants, phytochemical and functional group profiles of the plant species in stress conditions were investigated. Besides, changes in enzymes, beneficial bacterial populations and physico-chemical conditions and total oil and grease (TOG) contents in the contaminated soils were also studied. The results showed improvement in physico-chemical conditions, increase in beneficial bacterial population (4.1-5.4 folds) and decrease in TOG (31.3%) level of the contaminated soils by end of the experimental trials. The activities of dehydrogenase, urease, alkaline phosphatase, catalase, amylase and cellulase have increased in the range of 23.6-174.4% after introduction of L. aspera in the contaminated soils. Further, there were significant variations in leaf area index, chlorophyll and biomass contents of the experimental plant as against the initial level and control. Besides, the results also revealed significant deviations in the antioxidant and phytochemical profiles of L. aspera suggesting the enzymatic defense of the plant species in the crude oil contaminated soils. The fourier-transform infrared (FT-IR) analysis confirmed the uptake and metabolism of some hydrocarbon components by the experimental plant from the contaminated soils.