Antioxidative Responses of Cocos nucifera against Infestation by the Red Palm Weevil (RPW), Rhynchophorus ferrugineus, a New Invasive Coconut Pest in Malaysia

Abstract

Interaction between the Red Palm Weevil (RPW) and coconuts will stimulate the plants’ early response by producing the reactive oxygen species (ROS) which causes lipid peroxidation and membrane damage of the host plants. Thus, a multiple defense lines, including both scavenging enzymes and molecular antioxidants have been evolved to promptly inactivate these radicals. This study investigated the responses of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), α-tocopherol, ascorbic acid and carotenoids contents of three coconut cultivars which were PANDAN, MAWA and MATAG against the RPW infestation. The infested PANDAN and MAWA exhibited higher CAT, POD and APX specific activities of 2.60 ± 0.11, 5.0 ± 0.72 and 1.58 ± 0.20 units/mg protein for PANDAN whereas 1.13 ± 0.04, 39.38 ± 2.29 and 1.15 ± 0.16 units/mg, protein for MAWA) compared with controls. However, MATAG cultivar showed no significant difference (p<0.05) in the production of both enzymes except for POD specific activities.