Resistance of a plant against pests and pathogens is largely a function of its defense related proteins. In vivo induction of these proteins using natural extracts from different parts of plants is an environment-friendly measure of plant protection. The present study, therefore, focused on the evaluation of the ability of an aqueous extract from the leaves of Tagetes erecta (Marigold) in inducing the expression of four defense proteins Peroxidase (POX), Polyphenol Oxidase (PPO), Lipoxygenase (LOX) and Catalase (CAT) in Solanum lycopersicum (Tomato). The plants were raised under aseptic conditions. Eight weeks old plants were sprayed with the marigold extract on the third leaf from the base of each plant. Enzyme activities and isoform expression of POX, PPO, LOX and CAT were studied at both site of treatment and away from it. The results demonstrate that the extract could significantly enhance the activities of POX, PPO and CAT, and was able to induce additional isoforms of POX, PPO and LOX, which might be instrumental in enhancement of host resistance against several biotic and abiotic stresses.