Reactive oxygen species (ROS) scavenging systems are involved in various biotic and abiotic stresses. Genetic engineering of Hevea was attempted to strengthen plant defences against ROS accumulation. Hevea transgenic plant lines over-expressing cytosolic HbCuZnSOD gene driven by a 35S CAMV promoter were successfully established and regenerated. The overexpression affected somatic embryogenesis and in plant development. The water deficit tolerance of two fast-growing HbCuZnSOD over-expressing lines (TS5T3Af and TS4T8An) was evaluated. Plants from line TS4T8An displayed lower stomatal conductance, a higher proline content and an activation of all ROS-scavenging enzymes suggesting a better protection against ROS.