Role of phenolics in allelopathic interactions

Allelopathy refers to the beneficial or harmful effects of one plant on another plant through the release of chemicals from plant parts in both natural and agricultural systems. The plants produce thousands of chemicals for self defence against herbivores, pests and neighbouring plants. Phenolic compounds are major plant allelochemicals in ecosystem and they play key role in allelopathy. Phenolics exert allelopathic effects on various physiological processes in plants (inhibition of cell division, elongation, and submicroscopic structures, changes in membrane permeability and inhibition of plant nutrients uptake, plant photosynthesis and respiration, various enzymes functions and activities, synthesis of plant endogenous hormones and protein synthesis). The allelopathic effects of phenolics from trees, crops, medicinal plants and weeds have been reviewed in this Review and future areas of research are suggested.