Melatonin in higher plants: occurrence and possible functions

Abstract

: Melatonin may be ubiquitous in the plant kingdom. This review considers the evaluation of methods of melatonin determination in plant material and possible melatonin functions in plants. Concerning the determination methods, the only reliable techniques are liquid chromatography – mass spectrometry or gas chromatography – mass spectrometry after some purification steps of the extract. Melatonin was shown to delay flower induction in some photoperiodic plants and in the dinoflagellate Lingulodinium it replaces, in part, the requirement of darkness for cyst formation. Melatonin may also have a function as an antioxidant and it may possess some auxin‐like effects. Finally, it may act as a signal for interaction of plants with herbivores and pests. Further research is needed to clarify these potential functions.

Melatonin in plants

“…Variety of estimation techniques and methods resulted in data diversity. Some of the reported levels of MEL may be inaccurate because (1) extraction procedures were not properly determined in some cases, (2) MEL is rather unstable in plant extracts and published concentrations might be underestimated (Kolář and Macháčkova 2005).…”

Melatonin as an Endogenous Plant Regulatory Signal: Debates and Perspectives

“…Because melatonin exerts auxin-like effects on root initiation and coleoptile elongation, the possibility that melatonin itself may act as an auxin has been considered (Kolář and Macháčková 2005). Melatonin has an indole ring with a side chain at the C3 position and an unsaturated bond close to C3 similar to IAA (Fig.…”

Plant neurobiology: from sensory biology, via plant communication, to social plant behavior

“…This resembles the situation in animals (Cirelli et al 2005). Although melatonin was discovered in plants more than 10 years ago (Kolár and Machácková 2005;Hernandez-Ruiz 2006, 2007;Pandi-Perumal et al 2006), we know almost nothing about the roles of melatonin in plants despite the fact that it is biochemically closely related to auxin. Interestingly, in this respect, melatonin mimics auxin in the induction of lateral root primordia from pericycle cells (Arnao and Hernandez-Ruiz 2007).…”