IMMUNOGOLD LABELING OF XYLANS AND ARABINOXYLANS IN THE PLANT-CELL WALLS OF MAIZE STEM

Polyclonal antibodies against 4-O-methyl-glucuronoxylan and alpha L-1- 3 arabinofuranosyl poly-beta-D-1-4-xylopyranosyl were raised from rabb its. An immunocytochemical technique was used to localize xylans and a rabinoxylans in the plant cell walls of the apical internode of two ma ize lines of different digestibility. The sclerenchyma, fibres and xyl em (lignified tissues) and the parenchyma (non-Lignified tissue) were studied. The arabinoxylans were more heavily labelled than the xylans in the lignified tissues of the less digestible maize whereas in the m ore digestible line the labelling of the two polysaccharides was simil ar. The xylans and arabinoxylans were localized in the secondary cell wall. In both maize lines, labelling increased from the base upwards o f the apical internode, reflecting the changes in growth stage.