Effects of heavy metals on seed germination and protein content of Vigna radiata (l.) Wilczek

Rapid industrialization and urbanization processes has led to the incorporation of pollutants such as pesticides, petroleum products, acids and heavy metals in the natural resources like soil, water and air, thus degrading not only the quality of the environment, but also affecting both plants and animals. In this context, the study was carried out to assess and determine the cumulative effect of some selected heavy metals on seed germination of mung bean. Among the five selected heavy metals, mercury and copper treated seeds were found to be affected more seriously compared to other selected heavy metals. The physical parameters including shoot length and root length were recorded periodically in each sample group to know the response of germinating seeds against the selected heavy metals. Morphological changes in germinating seeds were noticeable in which colour faded from green to pale yellow and those treated with salts of Cu, Co and Mn turned brownish yellow. The selected heavy metals also showed marked effect on protein content and mitotic activity. Although reports exist on mechanisms by which the heavy metals act as stress and how plants have learnt to overcome, the future scope of this remains in excavating the signaling mechanisms in germinating seeds in response to heavy metal stress.