Transcripts of MYB-like genes respond to phosphorous and nitrogen deprivation in Arabidopsis

Planta. 2004 Oct;219(6):1003-9. doi: 10.1007/s00425-004-1305-7. Epub 2004 Jun 25.

Abstract

In Arabidopsis thaliana (L.) Heynh., AtPhr2 and AtNsr1 encode proteins with MYB-like and alpha-helical domains. They resemble CrPsr1, a nuclear-localized MYB protein that is critical for acclimation to phosphorous (P) starvation in the alga Chlamydomonas reinhardtii. Reverse transcription-polymerase chain reaction analysis of the first unique exons indicated that AtPhr2 mRNA increased as early as 6 h after P deprivation (-P), whereas nitrogen deprivation (-N) had no effect. The AtNsr1 mRNA level increased exclusively under -N, an increase first noted by 2 days in -N. In spite of P- and N-specific effects on expression of AtPhr2 and AtNsr1 there appeared to be P-N cross-talk at the whole-plant level. Total non-secreted acid phosphatase activity increased under both -P and -N within 2 days of deprivation. Further, the pho2-1/pho2-1 mutant, reported to be a phosphate accumulator, showed no increase in AtPhr2 mRNA in response to -P and a 70% reduction in the response of AtNsr1 mRNA to -N. Consistent with this pattern, there was no increase in acid phosphatase activity in pho2-1/pho2-1 plants deprived of P or N. However, when deprived of P, pho2-1/pho2-1 plants accumulated much higher levels of nitrate. T-DNA disruption of AtNsr1 resulted in altered expression of at least one nitrate transporter (AtNRT2.5). Further evidence of cross-talk between N and P responses was altered expression of N-responsive genes in pho2-1/pho2-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / biosynthesis
  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Chromosome Mapping
  • Gene Expression Regulation, Plant / physiology
  • Molecular Sequence Data
  • Mutation
  • Nitrogen / metabolism*
  • Phosphorus / metabolism*
  • RNA, Messenger / metabolism
  • RNA, Plant / metabolism
  • Sequence Alignment
  • Time Factors

Substances

  • Arabidopsis Proteins
  • Nsr1 protein, Arabidopsis
  • Phr2 protein, Arabidopsis
  • RNA, Messenger
  • RNA, Plant
  • Phosphorus
  • Acid Phosphatase
  • Nitrogen