Survival and adaptation of plants in their habitats involve sophisticated ecological events. For example, when attached by herbivores, elicitation of defense responses involves perception, processing and integration of external information into cellular and physiological machinery, ultimately leading to a massive molecular reprogramming. Except for the involvement of some transcription factors (TFs), a few imbedded in MPAK pathway, how defense signaling is modulated remains poorly understood. Regulatory small RNAs (smRNAs) have appeared as master regulators in cellular processes both in prokaryotes and eukaryotes. Information on their involvement in regulating plant defenses during herbivore attack is still limited. In our studies we are attempting deconvolution and reconstruction of a smRNA pathway that functionally regulates induced plant defenses. The evolution of smRNA-pathway effectors, the AGOs, is a dynamic process that could generate signatures of diversification of function of smRNA pathways in plants. Understanding molecular evolution of these components of smRNA machinery is providing further insights into mechanistic details of recruitment of specialized smRNAs. We are further expanding our studies to determine how such processes have responded to evolutionary pressures of polyploidization and domestication that have shaped agriculture, and in turn modern civilization.