A maize gene encoding an NADPH binding enzyme highly homologous to isoflavone reductases is activated in response to sulfur starvation

Plant Cell. 1996 Jan;8(1):69-80. doi: 10.1105/tpc.8.1.69.

Abstract

we isolated a novel gene that is selectively induced both in roots and shoots in response to sulfur starvation. This gene encodes a cytosolic, monomeric protein of 33 kD that selectively binds NADPH. The predicted polypeptide is highly homologous ( > 70%) to leguminous isoflavone reductases (IFRs), but the maize protein (IRL for isoflavone reductase-like) belongs to a novel family of proteins present in a variety of plants. Anti-IRL antibodies specifically recognize IFR polypeptides, yet the maize protein is unable to use various isoflavonoids as substrates. IRL expression is correlated closely to glutathione availability: it is persistently induced in seedlings whose glutathione content is about fourfold lower than controls, and it is down-regulated rapidly when control levels of glutathione are restored. This glutathione-dependent regulation indicates that maize IRL may play a crucial role in the establishment of a thiol-independent response to oxidative stress under glutathione shortage conditions.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Carrier Proteins / genetics*
  • Carrier Proteins / immunology
  • Carrier Proteins / metabolism
  • Cloning, Molecular
  • Cross Reactions
  • DNA, Complementary / genetics
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Glutathione / analysis
  • Immunoblotting
  • Intracellular Signaling Peptides and Proteins
  • Molecular Probe Techniques
  • Molecular Sequence Data
  • NADP / metabolism*
  • Oxidoreductases / genetics
  • Oxidoreductases Acting on CH-CH Group Donors*
  • Plant Proteins / genetics*
  • Plant Proteins / immunology
  • Plant Proteins / metabolism
  • RNA, Messenger / analysis
  • RNA, Plant / analysis
  • Recombinant Proteins / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Sulfates / metabolism
  • Sulfur / deficiency*
  • Zea mays / enzymology
  • Zea mays / genetics*

Substances

  • Carrier Proteins
  • DNA, Complementary
  • IRL protein, Zea mays
  • Intracellular Signaling Peptides and Proteins
  • Plant Proteins
  • RNA, Messenger
  • RNA, Plant
  • Recombinant Proteins
  • Sulfates
  • NADP
  • Sulfur
  • Oxidoreductases
  • vestitone reductase
  • Oxidoreductases Acting on CH-CH Group Donors
  • Glutathione

Associated data

  • GENBANK/D47630
  • GENBANK/U33318
  • GENBANK/Z49777