title: Accumulation of Phosphorus-Containing Compounds in Developing Seeds of Low-Phytate Pea (Pisum sativum L.) Mutants.
abstract: Low phytic acid (lpa) crops are low in phytic acid and high in inorganic phosphorus (Pi). In this study, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were grown in field trials for two years. The lpa genotypes were lower in IP₆ and higher in Pi when compared to CDC Bronco. The total P concentration was similar in lpa genotypes and CDC Bronco throughout the seed development. The action of myo-inositol phosphate synthase (MIPS) (EC 5.5.1.4) is the first and rate-limiting step in the phytic acid biosynthesis pathway. Aiming at understanding the genetic basis of the lpa mutation in the pea, a 1530 bp open reading frame of MIPS was amplified from CDC Bronco and the lpa genotypes. Sequencing results showed no difference in coding sequence in MIPS between CDC Bronco and lpa genotypes. Transcription levels of MIPS were relatively lower at 49 days after flowering (DAF) than at 14 DAF for CDC Bronco and lpa lines. This study elucidated the rate and accumulation of phosphorus compounds in lpa genotypes. The data also demonstrated that mutation in MIPS was not responsible for the lpa trait in these pea lines.
authors.affiliation: Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada. s.ask@usask.ca.
authors.forename: Arun S K
authors.initials: AS
authors.lastname: Shunmugam
authors.affiliation: National Research Council Canada, 110 Gymnasium Place, Saskatoon, SK S7N 0W9, Canada. Cheryl.bock@nrc-cnrc.gc.ca.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Bock
authors.affiliation: Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada. gene.arganosa@usask.ca.
authors.forename: Gene C
authors.initials: GC
authors.lastname: Arganosa
authors.affiliation: National Research Council Canada, 110 Gymnasium Place, Saskatoon, SK S7N 0W9, Canada. fawzy.georges@usask.ca.
authors.forename: Fawzy
authors.initials: F
authors.lastname: Georges
authors.affiliation: Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada. gr.gray@usask.ca.
authors.forename: Gordon R
authors.initials: GR
authors.lastname: Gray
authors.affiliation: Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada. tom.warkentin@usask.ca.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Warkentin
keywords: D-myo-inositol phosphate synthase (MIPS); phosphorus; phytate biosynthesis; phytic acid