This invention relates to newly identified polynucleotides and polypeptides in the phytic acid biosynthetic pathway, fragments, variants and derivatives of same; methods for making the polynucleotides, polypeptides, fragments, variants, derivatives and antagonists. In particular the invention relates to polynucleotides and polypeptides of the inositol 1,3,4-trisphosphate 5/6-kinase gene family. In particular this invention relates to using the newly identified polynucleotides and polypeptides to modulate the phytic acid biosynthesis in such a way as to decrease phytate and/or increase non-phytate phosphorous, especially in corn or soy animal feedstuffs.