Investigation of localization of xylan polysaccharide in plant cell walls using microscopy techniques

Lignocellulosic biomass is the most abundant renewable organic material on earth. Lignocellulose, which forms the cell walls of plants, basically consists of three compounds. These are cellulose, hemicellulose and lignin. Xylan, the polymer of xylose, is the main component that forms hemicellulose in woody plants. Hemicellulose joins the structure of the cell wall by bonding with cellulose and lignin. It is known that there is more xylan in the content of hemicellulose in hardwood plants. Xylan is mostly involved in the structure of the secondary cell wall. Studies on the structure and localization of xylan, which is the second most abundant biomass, are important. In this study, the model plant Arabidopsis thaliana was used to examine the localization of xylan polysaccharide in the plant cell wall. Tissue tracking procedures were applied to the samples taken from the stems of 3 and 6 week old Arabidopsis thaliana plants planted and grown in the medium, and sections were taken from the samples with an ultramicrotome. Afterwards, labeling was performed using cell wall-specific monoclonal antibodies by immunohistochemistry method. Monoclonal antibodies LM10, LM11, CCRC-M144, CCRC-M148, CCRC-M150 and CCRC-M154 were preferred because they recognized different structures on xylan polysaccharide. Finally, localization images of the antibodies were determined by fluorescence microscopy. When the localization of the antibodies was examined in the xylem and interfascicular cell walls, different binding motifs were observed. Additionally, the localization of some antibodies differed in plant samples at 3 and 6 weeks of age, depending on plant growth. Thus, the structural differences of xylan polysaccharide in the plant cell wall of Arabidopsis thaliana were revealed.