Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/8/2000
Publication Date: 11/5/2000
Citation: Shukla, S., Vantoai, T.T., Pratt, R. 2000. Molecular mechanism of the corn low phytic acid ipa 1 mutant. Meeting Abstract. Interpretive Summary:
Technical Abstract: The low phytic acid corn mutant (lpa 1) contains total P levels similar to wild-type kernels but the phytic acid is reduced by about 65%. The grain used for feed from these mutants is sufficient to satisfy the non-ruminant's dietary need of phosphorus. The research was conducted to determine the molecular mechanism of the lpa 1 mutation and to develop DNA markers linked to the trait. The lpa 1 mutant is mapped to the same position on the 1S chromosome with the MIPS gene coding for myo-inositol phosphate synthase, the first enzyme of the phytic acid biosynthetic pathway. The MIPS activity is 50-fold higher in the developing kernels of wild-type than of lpa 1plants. The 1S chromosome MIPS gene was cloned from genomic DNA of two pairs of wild-type and lpa 1 near isogenic lines. DNA sequencing identified several single nucleotide changes in the genomic clones which will be used in the development of SNP markers. The use of DNA markers to assist in the identification of heterozygous lines will reduce the number of generations for backcrossing by at least 50% and would save a great deal of time and resources in the development of elite lpa inbreds.