Metabolic interconversions of phosphorylated myo -inositol and related derivatives in developing B. napus seeds. Dashed arrow indicates the newly introduced methylation step. Solid lines represent established metabolic pathways. PI-K, phosphatidylinositol kinase; GolS, galactinol synthase; MIPS, myo-inositol phosphate synthase; InsPKs, myo-inositol kinases; PtdInsS, PtdIns synthase; PtdIns-PLC, PtdIns-specific phospholipase C; InsPtase, myo-inositol phosphate phosphatase; InsK, myo-inositol kinase; G-6-P, glucose-6-phosphate; DAG, diacylglycerol; UDP-gal, uridine diphosphate galactose; Ptd-CMP, phosphatidylcytosine monophosphate; PtdIns, phosphatidylinositol; PtdInsP, phosphatidylinositol monophosphate; Pi, inorganic phosphate.