title: Melatonin acts as a growth-stimulating compound in some monocot species.
abstract: In a recent study melatonin (N-acetyl-5-methoxytryptamine), a well-investigated animal molecule but minimally studied in plants, was seen to have a physiological role as growth-promoting molecule in lupin hypocotyls. In the present study, the role of melatonin as a growth promoter is extended to coleoptiles of canary grass, wheat, barley and oat, in which it shows a relative auxinic activity [with respect to indole-3-acetic acid (IAA), the main auxin in plants] of between 10 and 55%. In addition, melatonin is seen to have an important inhibitory growth effect on roots similar to that played by auxin. The quantitation by liquid chromatography with electrochemical detection and identification by tandem mass spectrometry of melatonin and IAA in etiolated coleoptiles of the monocots assayed showed that both compounds are present in similar levels in these tissues. These results point to the co-existence of auxin and melatonin in tissues and raises the possibility of their co-participation in some physiological actions as auxinic hormones in plants.
authors.affiliation: Department of Plant Physiology, University of Murcia, Murcia, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Hernández-Ruiz
authors.forename: Antonio
authors.initials: A
authors.lastname: Cano
authors.forename: Marino B
authors.initials: MB
authors.lastname: Arnao
mesh_terms: D018554:Avena / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006133:Growth Substances / Q000494:pharmacology*; D001467:Hordeum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology; D008550:Melatonin / Q000494:pharmacology*; D031783:Phalaris / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018547:Plant Stems / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D006109:Poaceae / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014908:Triticum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D006133:Growth Substances; D007210:Indoleacetic Acids; C030737:indoleacetic acid; D008550:Melatonin