Amelioration of lead and mercury effects on germination and rice seedling growth by antioxidants

Germination of two rice (Oryza sativa L.) cultivars (Ratna and IR 36) in the presence of 10 μM PbCl2 and 10 μM HgCl2 decreased germination percentage, germination index, shoot/root length, tolerance index and dry mass of shoots and roots. Mercury was more toxic than lead. Reduced glutathione (GSH), cysteine (Cys), ascorbic acid, and α-tocopherol alleviated the adverse effects of these metals on plants in the order GSH > Cys > ascorbic acid > α-tocopherol. The effects were more pronounced in tolerant cultivar IR 36 than in the relatively susceptible cultivar Ratna. This revised version was published online in July 2006 with corrections to the Cover Date.