Pectic epitopes in wheat mature grain are heterogeneously distributed.

<p>A. Half wheat grain harvested at 750°D and stained with toluidine blue showing the tissues of the grain and the regions 1, 2 and 3 where the immunofluorescence acquisitions were taken. B, C, D, E, F, G, H, I, J, K L. Immunofluorescence images localizing low (or non) methylesterified HG epitope using LM19 antibody (B, C, D and E), methylesterified HG epitope using LM20 antibody (F, G, H, I), rhamnogalacturonan I backbone epitope (J) using RUI antibody or galactan and arabinan side chains epitopes using LM5 and LM6 antibodies (K and L). In C and H, immunofluorescence and DIC images are merged to identify the labeled layers, the testa (t) and outer pericarp (op) for LM19 in C, and the outer wall of the cross cells (cc) and outer pericarp for LM20 in H. The sections were all treated with lichenase and xylanase prior to immunolabeling. An heterogeneity of labeling is noticed in the starchy endosperm (se) for both antibodies, in the dorsal region 1 the starchy endosperm is not labeled and in the peripheral region 2 and central region 3, it is heterogeneously labeled. al: aleurone layer, ne: nucellar epidermis. Bars represent 250 µm for A, 50 µm for K (the same scale was applied for B, D, E, F, G, I, J and L), and 20 µm for H and C.