Planta

, Volume 236, Issue 3, pp 809–824

Lipidomic analysis of N-acylphosphatidylethanolamine molecular species in Arabidopsis suggests feedback regulation by N-acylethanolamines

  • Aruna Kilaru
  • Pamela Tamura
  • Giorgis Isaac
  • Ruth Welti
  • Barney J. Venables
  • Edith Seier
  • Kent D. Chapman
Original Article

DOI: 10.1007/s00425-012-1669-z

Cite this article as:
Kilaru, A., Tamura, P., Isaac, G. et al. Planta (2012) 236: 809. doi:10.1007/s00425-012-1669-z

Abstract

N-Acylphosphatidylethanolamine (NAPE) and its hydrolysis product, N-acylethanolamine (NAE), are minor but ubiquitous lipids in multicellular eukaryotes. Various physiological processes are severely affected by altering the expression of fatty acid amide hydrolase (FAAH), an NAE-hydrolyzing enzyme. To determine the effect of altered FAAH activity on NAPE molecular species composition, NAE metabolism, and general membrane lipid metabolism, quantitative profiles of NAPEs, NAEs, galactolipids, and major and minor phospholipids for FAAH mutants of Arabidopsis were determined. The NAPE molecular species content was dramatically affected by reduced FAAH activity and elevated NAE content in faah knockouts, increasing by as much as 36-fold, far more than the NAE content, suggesting negative feedback regulation of phospholipase D-mediated NAPE hydrolysis by NAE. The N-acyl composition of NAPE remained similar to that of NAE, suggesting that the NAPE precursor pool largely determines NAE composition. Exogenous NAE 12:0 treatment elevated endogenous polyunsaturated NAE and NAPE levels in seedlings; NAE levels were increased more in faah knockouts than in wild-type or FAAH overexpressors. Treated seedlings with elevated NAE and NAPE levels showed impaired growth and reduced galactolipid synthesis by the “prokaryotic” (i.e., plastidic), but not the “eukaryotic” (i.e., extraplastidic), pathway. Overall, our data provide new insights into the regulation of NAPE–NAE metabolism and coordination of membrane lipid metabolism and seedling development.

Keywords

Mass spectrometryLipidomicsLauroylethanolamidePhospholipid

Abbreviations

ABA

Abscisic acid

DGDG

Digalactosyldiacylglycerol

EA

Ethanolamine

FAAH

Fatty acid amide hydrolase

FFA

Free fatty acid

FW

Fresh weight

KO

Knock-out

LOX

Lipoxygenase

MGDG

Monogalactosyldiacylglycerol

MS

Mass spectrometry

NAE

N-acylethanolamine

NAPE

N-acyl PE

NL

Neutral loss

OE

Overexpressor

PA

Phosphatidic acid

PC

Phosphatidylcholine

PE

Phosphatidylethanolamine

PG

Phosphatidylglycerol

PI

Phosphatidylinositol

PLD

Phospholipase D

Pre

Precursor

PS

Phosphatidylserine

PU

Polyunsaturated

SPE

Solid phase extraction

X:Y

Designates fatty acid or total acyl carbons:total carbon–carbon double bonds

Supplementary material

425_2012_1669_MOESM1_ESM.xlsx (162 kb)
Supplementary material 1 (XLSX 161 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Aruna Kilaru
    • 1
    • 2
  • Pamela Tamura
    • 3
  • Giorgis Isaac
    • 3
    • 5
  • Ruth Welti
    • 3
  • Barney J. Venables
    • 2
  • Edith Seier
    • 4
  • Kent D. Chapman
    • 2
  1. 1.Department of Biological SciencesEast Tennessee State UniversityJohnson CityUSA
  2. 2.Department of Biological Sciences, Center for Plant Lipid ResearchUniversity of North TexasDentonUSA
  3. 3.Division of Biology, Kansas Lipidomics Research CenterKansas State UniversityManhattanUSA
  4. 4.Department of Mathematics and StatisticsEast Tennessee State UniversityJohnson CityUSA
  5. 5.Waters CorporationMilfordUSA