Heavy Metal Accumulation and Metabolic Changes Associated with Pollution in Vernonia Cinerea (L.) Less. Growing Under Ecologically Different Habitats

Vernonia cinerea (L.) Less. is a major ingredient of natural medicine. Environmental stresses lead to a series of morphological, physiological, biochemical and molecular changes that adversely affect the growth and metabolism of plants. These abiotic stresses are highly responsible for dramatic changes on chemical constituents of plants. The research was performed to analyze the physiological and biochemical changes in V. cinerea under polluted and non-polluted habitats and also to determine the heavy metal accumulation under polluted and non-polluted habitats. The studies revealed clear difference in the chlorophyll, malondialdehyde, total protein, proline and total carbohydrate content among V. cinerea under polluted and non-polluted habitats. Plants collected from non-polluted habitats showed higher amount of total chlorophyll than the plants collected from polluted habitats. Thus it was clear that the samples from non-polluted habitats were photo synthetically very efficient. Total protein, malondialdehyde and proline content were higher in plants collected from polluted habitats. Moreover, heavy metal quantification of samples showed comparatively high amount of heavy metals in V. cinerea of polluted plants than non-polluted plants. Zinc accumulation was found to be higher in all V. cinerea plants especially in road side habitats. Furthermore, the accumulation of heavy metals was higher in leaves and stem when compared to roots. The metal concentrations in shoots are invariably greater than in roots, showing special ability of the plant to absorb and transport metals and store them in their above-ground part. Thus the present study revealed remarkable biochemical changes in the plants which were grown under polluted habitats and the study also suggests the collection of V. cinerea plants from non-polluted habitats for medicinal purposes, because there will be a definite changes in the medicinal properties of the plants under stress.