A.K. Cowan, C. Leung, CH. Santori
Lyso-phosphatidylethanolamine (LPE) is a naturally occurring phospholipid derived by phospholipase A2 (PLA2) hydrolysis of phosphatidylethanolamine (PE) and was commercialized for use as a bioregulator due to its ability to stimulate fruit ripening but delay senescence. In order to elaborate on this proposed mechanism of action the effect of LPE on plant growth and development was investigated using several plant tissue systems and by analyzing the response of potential target enzymes to applied LPE in expanding radish cotyledons. Results show that LPE stimulates elongation growth of oat coleoptiles, delays dark-induced leaf senescence in broad bean, enhances fruit set in tomato, and promotes cytokinin-induced cotyledon expansion in radish. Furthermore, LPE-treated radish cotyledons display increased protection from high temperature-induced oxidative stress. P-type plasma membrane ATPase activity from roots of corn and mung bean was not affected by LPE whereas F-/V-type ATPase activity was substantially reduced. LPE treatment of expanding radish cotyledons resulted in the transient induction of acid invertase (Ac-INV, EC, phenylalanine ammonia lyase (PAL, EC, endo β-1,3(4)-glucanase (BG, EC and to a lesser extent peroxidase (POD, EC, but suppression of polyphenol oxidase (PPO, EC) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR, EC activity. These findings are interpreted in terms of a mode of action for LPE in plants and the potential growth regulator property of LPE is discussed.
Cowan, A.K., Leung, C. and Santori, CH. (2006). LYSO-PHOSPHATIDYLETHANOLAMINE (LPE) AS A PLANT BIOREGULATOR. Acta Hortic. 727, 527-536
DOI: 10.17660/ActaHortic.2006.727.65
bioassays, enzymes, expansion growth, lyso-phosphatidylethanolamine (LPE), phospholipid, mode of action

Acta Horticulturae