Copper toxicity In plants: a review and a case study on tea

Abstract

Copper in trace amounts is essential for various metabollc processes In the plant such as photosynthes is, ..:arbohydra te distribution, and protein metabolism but at high concentration it causes physiological stress through genera tion of free radicals that Induce the production of reactive oxygen species (ROS) via Haber \ i\1eiss and Fenton reactions . Copper-Induced generation of hydrogen peroxide, hydroxyl radicals, or other react!\~ oxygen species has been directly .correlated with the damage to protein and lipids that may lead to reduced growth and even death. Tea ( Camellia sinensls (L.) O. Kuntze) is an economically important plantation crop in India w ith round the year productivity. Copper based fungicides are cheap and effective i n controlling funga l diseases and are used consistently throughout the year to combat different fungal diseases that pose a major threat to tea production. Excess Cu 2 + has been found to alter several physiochemical parameters in the tea plants. A more detailed study on mechanisms of Cu 2+ toxicity at the gene level is warranted.