Biosynthesis of Pectic Substance in Germinating Pollen: Labeling with Myoinositol-2- ¹⁴ C

Growing pollen tubes provide a convenient system for study of the biosynthesis of primary cell wall components of higher plants. Pollen of Lilium longiflorum (cv. Ace) which was germinated and grown for periods up to 8 hours in a medium that contained pentaerythritol, a metabolically inert substitute for sucrose, removed myoinositol from the medium and utilized this cyclitol as a precursor of galacturonosyl and pentosyl units for the biosynthesis of pectic substance in pollen tube walls.