pho3: a phosphorus-deficient mutant of Arabidopsis thaliana (L.) Heynh

Planta. 2001 Mar;212(4):529-34. doi: 10.1007/s004250000450.


A novel P-deficient mutant of Arabidopsis thaliana, pho3, was isolated by screening for root acid phosphatase (APase) activity in plants grown under low-P conditions. pho3 had 30% less APase activity in roots than the wild type and, in contrast to wild-type plants, root APase activity did not increase in response to growth in low P. However, shoot APase activity was higher in pho3 than in the wild-type plants. In addition, the pho3 mutant had a P-deficient phenotype, even when grown in P-sufficient conditions. The total P content of 11-d-old pho3 plants, grown in agar media with a plentiful supply of P, was about 25% lower than the wild-type level in the shoot, and about 65% lower in the roots. In the rosette leaves of mature soil-grown pho3 plants the total P content was again reduced, to about 50% of wild-type levels. pho3 exhibited a number of characteristics normally associated with low-P stress, including severely reduced growth, increased anthocyanin content (at least 100-fold greater than the wild type in soil-grown plants) and starch accumulation. The results suggest that the mutant is unable to respond to low internal P levels, and may lack a transporter or a signalling component involved in regulating P nutrition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / biosynthesis
  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Enzyme Induction
  • Genes, Plant*
  • Mutation*
  • Phenotype
  • Phosphorus / analysis
  • Phosphorus / metabolism*
  • Phosphorus / pharmacology
  • Pigments, Biological / analysis
  • Plant Roots / enzymology
  • Plant Shoots / enzymology
  • Starch / metabolism


  • Pigments, Biological
  • Phosphorus
  • Starch
  • Acid Phosphatase