The Vr-PLC3 gene encodes a putative plasma membrane-localized phosphoinositide-specific phospholipase C whose expression is induced by abiotic stress in mung bean (Vigna radiata L.)

FEBS Lett. 2004 Jan 2;556(1-3):127-36. doi: 10.1016/s0014-5793(03)01388-7.

Abstract

Phosphoinositide-specific phospholipase C (PI-PLC) catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate to generate inositol 1,4,5-trisphosphate and diacylglycerol, both of which act as secondary messengers in animal cells. In this report, we identified in Vigna radiata L. (mung bean) three distinct partial cDNAs (pVr-PLC1, pVr-PLC2, and pVr-PLC3), which encode forms of putative PI-PLC. All three Vr-PLC genes were transcriptionally active and displayed unique patterns of expression. The Vr-PLC1 and Vr-PLC2 transcripts were constitutively expressed to varying degrees in every tissue of mung bean plants examined. In contrast, the Vr-PLC3 mRNA level was very low under normal growth conditions and was rapidly induced in an abscisic acid-independent manner under environmental stress conditions (drought and high salinity). An isolated genomic clone, about 8.2 kb in length, showed that Vr-PLC1 and Vr-PLC3 are in tandem array in the mung bean genome. The predicted primary sequence of Vr-PLC3 (M(r)=67.4 kDa) is reminiscent of the delta-isoform of animal enzymes which contain core sequences found in typical PI-PLCs, such as the catalytic domain comprising X and Y motifs, a lipid-binding C2 domain, and the less conserved EF-hand domain. Results of in vivo targeting experiment using a green fluorescent protein (GFP) showed that the GFP-Vr-PLC3 fusion protein was localized primarily to the plasma membrane of the Arabidopsis protoplast. The C2 domain was essential for Vr-PLC3 to be targeted to the plasma membrane. The possible biological functions of stress-responsive Vr-PLC3 in mung bean plants are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Membrane / enzymology
  • Conserved Sequence
  • Fabaceae / enzymology*
  • Fabaceae / genetics*
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Genes, Plant*
  • Isoenzymes / biosynthesis
  • Isoenzymes / genetics
  • Kinetics
  • Mannitol / pharmacology
  • Molecular Sequence Data
  • Phosphatidylinositol Diacylglycerol-Lyase / biosynthesis*
  • Phosphatidylinositol Diacylglycerol-Lyase / genetics*
  • Phosphoinositide Phospholipase C
  • Phylogeny
  • Plant Structures / genetics
  • Plant Structures / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Sequence Homology, Amino Acid
  • Sodium Chloride / pharmacology

Substances

  • Isoenzymes
  • RNA, Messenger
  • RNA, Plant
  • Mannitol
  • Sodium Chloride
  • Phosphoinositide Phospholipase C
  • Phosphatidylinositol Diacylglycerol-Lyase

Associated data

  • GENBANK/AY394078
  • GENBANK/AY394079
  • GENBANK/AY461431