title: ABA-induced 'lipid melting' and its reversal by umbelliferone in the plasmalemma of guard cell protoplasts: a breakthrough in plant hormone-receptor binding and hormone action.
abstract: The dynamics of stomatal opening and closure had to date been ascribed largely to the K(+)-fluxes and cell wall elasticity. Using protoplasts of guard cells of Vicia faba as model system, we document convincing first hand evidence a that lipid phase alterations could regulate ABA-induced closure of stomates and its reversal by umbelliferone. Backed up by the presence of plasmalemma-located ABA-receptor in guard cells, a novel theory could be put forth explaining guard cell opening and closure mediated by hormone induced reconfiguration via a probable lipid-protein lattice modification. The phase reversal of the plasmalemma by umbelliferone is postulated to be through modified hormone receptor complex structure, which is yet to be substantiated.
authors.affiliation: School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Indore, India.
authors.forename: S
authors.initials: S
authors.lastname: Purohit
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: M
authors.initials: M
authors.lastname: Laloraya
authors.forename: S
authors.initials: S
authors.lastname: Bharti
authors.forename: M M
authors.initials: MM
authors.lastname: Laloraya
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D008560:Membrane Fluidity / Q000187:drug effects; D009532:Nickel / Q000494:pharmacology; D018521:Plant Physiological Phenomena; D011189:Potassium Chloride / Q000494:pharmacology; D011523:Protoplasts / Q000187:drug effects / Q000502:physiology; D014468:Umbelliferones / Q000494:pharmacology*
chemical_list: D005609:Free Radicals; D014468:Umbelliferones; C031477:7-hydroxycoumarin; D011189:Potassium Chloride; C022838:nickel chloride; D000040:Abscisic Acid; D009532:Nickel