Origin and seed phenotype of maize low phytic acid 1-1 and low phytic acid 2-1

Plant Physiol. 2000 Sep;124(1):355-68. doi: 10.1104/pp.124.1.355.

Abstract

Phytic acid (myo-inositol-1, 2, 3, 4, 5, 6-hexakisphosphate or Ins P(6)) typically represents approximately 75% to 80% of maize (Zea mays) seed total P. Here we describe the origin, inheritance, and seed phenotype of two non-lethal maize low phytic acid mutants, lpa1-1 and lpa2-1. The loci map to two sites on chromosome 1S. Seed phytic acid P is reduced in these mutants by 50% to 66% but seed total P is unaltered. The decrease in phytic acid P in mature lpa1-1 seeds is accompanied by a corresponding increase in inorganic phosphate (P(i)). In mature lpa2-1 seed it is accompanied by increases in P(i) and at least three other myo-inositol (Ins) phosphates (and/or their respective enantiomers): D-Ins(1,2,4,5,6) P(5); D-Ins (1,4,5,6) P(4); and D-Ins(1,2,6) P(3). In both cases the sum of seed P(i) and Ins phosphates (including phytic acid) is constant and similar to that observed in normal seeds. In both mutants P chemistry appears to be perturbed throughout seed development. Homozygosity for either mutant results in a seed dry weight loss, ranging from 4% to 23%. These results indicate that phytic acid metabolism during seed development is not solely responsible for P homeostasis and indicate that the phytic acid concentration typical of a normal maize seed is not essential to seed function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Electrophoresis / methods
  • Inositol Phosphates / chemistry
  • Inositol Phosphates / metabolism
  • Magnetic Resonance Spectroscopy
  • Mutation
  • Phenotype
  • Phosphates / isolation & purification
  • Phosphates / metabolism
  • Physical Chromosome Mapping
  • Phytic Acid / biosynthesis
  • Phytic Acid / metabolism*
  • Seeds / growth & development
  • Seeds / physiology*
  • Stereoisomerism
  • Zea mays / genetics
  • Zea mays / growth & development
  • Zea mays / physiology*

Substances

  • Inositol Phosphates
  • Phosphates
  • Phytic Acid