The click-compatible sugar 6-deoxy-alkynyl glucose metabolically incorporates into Arabidopsis root hair tips and arrests their growth

Plant cell walls are dynamic structures whose polysaccharide components are rearranged and recycled during growth and morphogenesis. Covalent fluorescent tagging of these polysaccharides following a metabolic labeling approach can help elucidate these changes. Herein reported are the synthesis and seedling-incorporation of a plant polysaccharide chemical reporter, 6-deoxy-alkynyl glucose (6dAG), that is modeled on d-glucose. Whereas fucose-alkyne, a previously reported chemical reporter for pectin, incorporates diffusely throughout growing cell walls, 6dAG incorporated specifically into root hair tips. This incorporation occurs in a time- and concentration-dependent manner. 6dAG exposure both induces and colocalizes with callose deposition in this tissue, and arrests both root hair and root growth. These results show that plants can incorporate an additional alkynyl-modified sugar analog into their metabolism, and into a discrete subcellular location.