Wound induced tanscriptional regulation of benzylisoquinoline pathway and characterization of wound inducible PsWRKY transcription factor from Papaver somniferum

PLoS One. 2013;8(1):e52784. doi: 10.1371/journal.pone.0052784. Epub 2013 Jan 30.

Abstract

Wounding is required to be made in the walls of the green seed pod of Opium poppy prior exudation of latex. To withstand this kind of trauma plants regulate expression of some metabolites through an induced transcript level. 167 unique wound-inducible ESTs were identified by a repetitive round of cDNA subtraction after 5 hours of wounding in Papaver somniferum seedlings. Further repetitive reverse northern analysis of these ESTs revealed 80 transcripts showing more than two fold induction, validated through semi-quantitative RT-PCR & real time expression analysis. One of the major classified categories among identified ESTs belonged to benzylisoquinoline transcripts. Tissue specific metabolite analysis of benzylisoquinoline alkaloids (BIAs) in response to wounding revealed increased accumulation of narcotine and papaverine. Promoter analysis of seven transcripts of BIAs pathway showed the presence of W-box cis-element with the consensus sequence of TGAC, which is the proposed binding site for WRKY type transcription factors. One of the Wound inducible 'WRKY' EST isolated from our subtracted library was made full-length and named as 'PsWRKY'. Bacterially expressed PsWRKY interacted with the W-box element having consensus sequence TTGACT/C present in the promoter region of BIAs biosynthetic pathway genes. PsWRKY further activated the TYDC promoter in yeast and transiently in tobacco BY2 cells. Preferential expression of PsWRKY in straw and capsule and its interaction with consensus W-box element present in BIAs pathway gene transcripts suggest its possible involvement in the wound induced regulation of BIAs pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / metabolism
  • Benzylisoquinolines / metabolism*
  • Expressed Sequence Tags / metabolism*
  • Gene Expression Regulation, Plant
  • Metabolic Networks and Pathways
  • Papaver / genetics
  • Papaver / metabolism*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Promoter Regions, Genetic
  • Sequence Homology, Amino Acid
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Wounds and Injuries

Substances

  • Alkaloids
  • Benzylisoquinolines
  • Plant Proteins
  • Transcription Factors

Grants and funding

The authors acknowledge Council of Scientific and Industrial Research (CSIR) Network Project (NWP08), and Department of Science and Technology Fast Track Project (Number: SR/FT/LS-189/2009) from Department of Science and Technology, India for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.