Melatonin as an antioxidant and its semi-lunar rhythm in green macroalga Ulva sp.

Ofir Tal, Abraham Haim, Orna Harel, Yoram Gerchman

Research output: Contribution to journalArticlepeer-review


The presence and role of melatonin in plants are still under debate owing to difficulties of identification and quantification. Accordingly, although it has been frequently proposed that melatonin acts as an antioxidant in phototrophic organisms, experimental data on its physiological role are scarce. This study describes the use of a rapid and simple new method for quantification of melatonin in the marine macroalga Ulva sp., organisms routinely exposed to tide-related environmental stresses and known for their high tolerance to abiotic conditions. The method was used here to show that exposure to oxidative stress-inducing environmental conditions (elevated temperature and heavy metals) induced a rise in melatonin level in the algae. Addition of exogenous melatonin alleviated the algae from cadmium-induced stress. Interestingly, although the algae were taken from a culture growing free floating and kept under constant photoperiod and water level, they exhibited a semi-lunar rhythm of melatonin levels that correlated with predicted spring tides. The correlation can probably be interpreted as reflecting preparation for predicted low tides, when the algae are exposed to increasing temperature, desiccation, and salinity, all known to induce oxidative stress. Given the simplicity of the described method it can easily be adapted for the study of melatonin in many other phototrophic organisms. These results provide, for the first time, experimental data that support both an antioxidant role for melatonin and its semi-lunar rhythm in macroalgae.

Original languageEnglish
Pages (from-to)1903-1910
Number of pages8
JournalJournal of Experimental Botany
Issue number6
StatePublished - Mar 2011
Externally publishedYes


  • TLC
  • antioxidant
  • heavy metals
  • macroalgae
  • melatonin
  • oxidative stress
  • phytomelatonin
  • semi-lunar rhythms
  • superoxide dismutase (SOD)

ASJC Scopus subject areas

  • Physiology
  • Plant Science


Dive into the research topics of 'Melatonin as an antioxidant and its semi-lunar rhythm in green macroalga Ulva sp.'. Together they form a unique fingerprint.

Cite this