Figure 5

Iron distribution in P. coccineus and P. lunatus seeds. Perls' Prussian blue staining of P. coccineus and P. lunatus seeds. a to g: Beans soaked 18 hours prior to staining. a: Stained seed coats and cotyledons from two P. coccineus batches purchased in Denmark (1 and 2), two P. coccineus genotypes (G35171 and G35172), and two P. lunatus genotypes (G25350 and G25381A). b to g: Close up stereomicroscope pictures of the samples in a. h to n: P. coccineus batch 1, o: P. lunatus G25381, and p, q: P. lunatus G25350. Stereomicroscopy of stained non-soaked beans (h and i) and of beans soaked in water for 2.5 hours prior to staining (j and k). h and j: Pictures of cotyledons, the blue stained provascular region (pvb) is indicated. i and k: Images of embryonic axes. l: Close up picture of the provascular region. m to q are light microscopy of thin cotyledon sections. m, n, p, and q: seeds were soaked in water for 18-24 hours before dissection and staining. o: dry seeds were dissected and soaked in 70% ethanol for 24 hours prior to PPB staining. Filled arrows point at iron stained cells and open arrows point at small iron stained spots. am: amyloplasts, rad: radicles, pvb: provascular bundles, cot: cotyledons. Scale bars in a: 1 cm, in b to k: 1 mm, in l to n: 0.1 mm, and in o to q: 0.01 mm.