Abstract:

Melatonin (N-acetyl-5-methoxytryptamine) is a well-known hormone of vertebrate, which is synthesized in pineal gland and secreted to the blood in animals. Melatonin is generally considered to be the chemical expression of darkness. Melatonin has been detected in a number of plant species. Its role in the plant kingdom is not clear enough. The suggested functional implications include the coordination of photoperiodic responses and regulation of plant growth, its participation as a free radical scavenging agent and up regulator of certain protective enzymes in the senescent process. This review presented a summary of the investigations in the plant melatonin field, and pointed out the problems. The potential functions of melatonin in plant kingdom were also predicted.