The biochemical pathways encompassing induced resistance involve oxidizing enzymes such as PPO (Polyphenol Oxidase), PO (Peroxidase) and LOX (Lypoxygenase). Increased activities of these enzymes in plants serve as markers for visualizing induced resistance. Induced resistance, being an active defense mechanism, results from the expression of PR-proteins, low molecular weight compounds like phytoalexins and proteinase inhibitors. This paper highlights on the spatial induction, variability and persistence of induced defenses responses in Lycopersicon esculentum Mill. using lepidopterans, aphids and mechanical wounding as elicitors. The early signally events upon wounding by an insect resulting in the release of elicitors JA, Ethylene, Glycans and Absisic acid and the transmission of signals through unwounded sites is described. The practical utility of induced resistance is discussed based on the results of the systematic small scale laboratory essays.