Advertisement

Molecular and General Genetics MGG

, Volume 253, Issue 3, pp 334–341 | Cite as

Reciprocal regulation of Δ1-pyrroline-5-carboxylate synthetase and proline dehydrogenase genes controls proline levels during and after osmotic stress in plants

  • Z. Peng
  • Q. Lu
  • D. P. S. Verma
ORIGINAL PAPER

Abstract

 Plants generally accumulate free proline under osmotic stress conditions. Upon removal of the osmotic stress, the proline levels return to normal. In order to understand the mechanisms involved in regulating the levels of proline, we cloned and characterized a proline dehydrogenase (PDH) cDNA from Arabidopsis thaliana (AtPDH). The 1745 bp cDNA contains a major open reading frame encoding a peptide of 499 amino acids. The deduced amino acid sequence has high homology with both Saccharomyces cerevisiae and Drosophila melanogaster proline oxidases and contains a putative mitochondrial targeting sequence. When expressed in yeast, the AtPDH cDNA complemented a yeast put1 mutation and exhibited proline oxidase activity. We also determined the free proline contents and the Δ1-pyrroline-5-carboxylate synthetase (P5CS) and PDH mRNA levels under different osmotic stress and recovery conditions. The results demonstrated that the removal of free proline during the recovery from salinity or dehydration stress involves an induction of the PDH gene while the activity of P5CS declines. The reciprocal regulation of P5CS and PDH genes appears to be a key mechanism in the control of the levels of proline during and after osmotic stress. The PDH gene was also significantly induced by exogenously applied proline. The induction of PDH by proline, however, was inhibited by salt stress.

Key words Proline dehydrogenase cDNA Prolineoxidase Transcriptional regulation Osmotic stress Arabidopsis thaliana 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Z. Peng
    • 1
  • Q. Lu
    • 2
  • D. P. S. Verma
    • 1
  1. 1.Department of Plant Biology, Ohio State University, Columbus, OH 43210, USAUS
  2. 2.Plant Biotechnology Center, Ohio State University, Columbus OH 43210, USAUS

Personalised recommendations