Abstract: Polyphenol oxidase (PPO) is a ubiquitous copper metalloprotein in the plastids of many plants, fungi and insects. It catalyzes 2 distinct reactions: the hydroxylation of monophenols to o-diphenols and the dehydrogenation of o-dihydroxyphenols to o-quinones. It is believed to be the primary response for the deleterious browning of many fruits and vegetables and is thought to be involved in plant photosynthesis, plant-pest interactions, growth and development, and flower coloration. The present review attempts to highlight the recent advances in research of polyphenol oxidase in cellular and molecular genetics and production.