Plant Molecular Biology

, 68:173

Identification, cloning and characterization of a GDSL lipase secreted into the nectar of Jacaranda mimosifolia

  • Brian W. Kram
  • Elizabeth A. Bainbridge
  • M. Ann D. N. Perera
  • Clay Carter
Article

DOI: 10.1007/s11103-008-9361-1

Cite this article as:
Kram, B.W., Bainbridge, E.A., Perera, M.A.D.N. et al. Plant Mol Biol (2008) 68: 173. doi:10.1007/s11103-008-9361-1

Abstract

The presence and function of several proteins secreted into floral nectars has been described in recent years. Here we report the presence of at least eight distinct proteins secreted into the floral nectar of the tropical tree Jacaranda mimosifolia (Bignoniaceae). Steps were initiated to identify and characterize these proteins in order to determine potential functions. The N-terminal sequence of the major Jacaranda nectar protein, JNP1, at 43 kDa contained similarity with members of the plant GDSL lipase/esterase gene family. Based upon this sequence, a full-length cDNA was isolated and predicted to encode a mature protein of 339 amino acids with a molecular mass of 37 kDa. Both raw nectar and heterologously expressed JNP1 displayed lipase/esterase activities. Interestingly, J. mimosifolia flowers produce an opaque, white colored nectar containing spherical, lipophilic particles approximately 5 μm in diameter and smaller. GS-MS analysis also identified the accumulation of free fatty acids within the nectar. It is proposed that JNP1 hydrolyzes Jacaranda nectar lipids with the concomitant release of free fatty acids. Potential functions of JNP1 in relation to pollinator attraction and prevention of microbial growth within nectar are briefly discussed.

Keywords

GDSL lipaseJacaranda mimosifoliaNectarNectariesNectaryPollination

Abbreviations

JNP1

Jacaranda nectar protein 1

PNB

Para-nitrophenyl butyrate

SDS PAGE

Sodium dodecyl sulfate polyacrylamide gel electrophoresis

GC-MS

Gas chromatography-mass spectrometry

RT PCR

Reverse transcriptase polymerase chain reaction

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Brian W. Kram
    • 1
  • Elizabeth A. Bainbridge
    • 2
  • M. Ann D. N. Perera
    • 2
  • Clay Carter
    • 1
  1. 1.Department of BiologyUniversity of Minnesota DuluthDuluthUSA
  2. 2.W.M. Keck Metabolomics Research LaboratoryIowa State UniversityAmesUSA