Responses of Camellia sinensis cultivars to Cu and Al stress

The response of Camellia sinensis (L.) O. Kuntze cultivars Chinary and Assamica to Cu and Al stresses was investigated. Exposure to 100 A mu M CuSO4 or 100 A mu M AlCl3 led to accumulation of reactive oxygen species (ROS) more in Assamica than in Chinary. Proline content was higher in Chinary compared to Assamica, while chlorophyll and protein contents decreased upon Cu and Al exposure in both the cultivars. Expression of glutathione biosynthetic enzymes gamma-glutamylcysteinyl synthetase (gamma-ECS) and glutathione synthetase (GSHS) was elevated. Phytochelatin synthase (PCS), an enzyme involved in phytochelatins synthesis by using glutathione as a substrate was up-regulated at its transcript level more in Chinary than in Assamica. These results suggest that Chinary could be more tolerant than Assamica.