Triacontanol and jasmonic acid differentially modulate the lipid organization as evidenced by the fluorescent probe behavior and 31P nuclear magnetic resonance shifts in model membranes.
Fluorescence resonance energy transfer (FRET), time-resolved fluorescence and anisotropy decays were determined in large unilamellar vesicles (LUVs) of egg phosphatidylcholine with the FRET pair N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dipalmitoyl-sn-glycero-3-phospho-ethanolamine as donor and lissamine rhodamine B 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine as acceptor, using 2-ps pulses from a Ti:sapphire laser on LUVs with incorporated plant growth regulators: triacontanol (TRIA) and jasmonic acid (JA). FRET efficiency, energy transfer rate, rotation correlation time, microviscosity, and diffusion coefficient of lateral diffusion of lipids were calculated from these results. It was observed that TRIA and JA differentially modulated all parameters studied. The effect of JA in such modulations was always partially reversed by TRIA. Also, the generalized polarization of laurdan fluorescence indicated that JA enhances the degree of hydration in lipid bilayers to a larger extent than does TRIA. Solid-state (31)P magic-angle spinning nuclear magnetic resonance spectra of LUVs showed two chemical shifts, at 0.009 and -11.988 ppm, at low temperatures (20 degrees C), while at increasing temperatures (20-60 degrees C) only one (at -11.988 ppm) was prominent and the other (0.009 ppm) gradually became obscure. However, LUVs with TRIA exhibited only one of the shifts at 0.353 ppm even at lower temperatures and JA did not affect the chemical shifts.
Department of Botany, Karnatak University, Dharwad 580 003, India. gshivakumaraswamy@gmail.com
G
G
Sivakumar Swamy
Sivakumar G
SG
Swamy
K
K
Ramanarayan
Laxmi S
LS
Inamdar
Sanjeev R
SR
Inamdar
D003517:Cyclopentanes / Q000494:pharmacology*; D005233:Fatty Alcohols / Q000494:pharmacology*; D005454:Fluorescence Polarization; D031541:Fluorescence Resonance Energy Transfer; D009682:Magnetic Resonance Spectroscopy; D008560:Membrane Fluidity / Q000187:drug effects*; D008563:Membrane Lipids / Q000737:chemistry*; D054883:Oxylipins / Q000494:pharmacology*; D010761:Phosphorus Radioisotopes; D053835:Unilamellar Liposomes / Q000737:chemistry*
D003517:Cyclopentanes; D005233:Fatty Alcohols; D008563:Membrane Lipids; D054883:Oxylipins; D010761:Phosphorus Radioisotopes; D053835:Unilamellar Liposomes; C011006:jasmonic acid; C047578:1-triacontanol