Mixed linkage (1,3;1,4)-β-glucan (MLG) is a major non-cellulosic polysaccharide of the commelinid monocot cell wall and an important soluble dietary fibre component found in abundance in cereal grains. Despite its importance, relatively little is known about the molecular mechanisms involved in the synthesis and assembly of this polysaccharide. Using functional genomics, the commelinid-specific Cellulose Synthase-Like (CSL) F, CSLH and CSLJ multi-gene families within the larger CAZy GT2 family have been identified as encoding the catalytic components of the MLG synthase enzyme (1, 2). The cellulose synthase-like F6 (CSLF6) protein is responsible for the majority of MLG present in the grasses, yet little is known about its regulation. For this purpose we are using a Lolium multiflorum (Italian rye grass) cell suspension culture system that makes abundant MLG in its walls (approx. 20-30%) to enrich the CSLF6 protein and identify the post-translational modifications (PTMs) present.  The modifications included in this study are S-acylation, phosphorylation and disulphide bonding. With improved knowledge of the PTMs present on CSLF6 we can gain insights into its regulation and the production of MLG.