Cereal grains are a major global food source, constituting ~60% of daily calorific intake globally. Mixed linkage (1,3;1,4)-β-glucan (MLG) is a major non-cellulosic polysaccharide of cereal grain cell walls and an important soluble dietary fibre component found at high levels in species such as oat and barley. Despite its importance, relatively little is known about the regulation of MLG biosynthesis. The Cellulose Synthase-Like (CSL) F, CSLH and CSLJ subfamilies within the CAZy GT2 family have been identified as encoding the catalytic components of MLG synthases. We have adopted a multi-disciplinary approach to study CSLF6, the major MLG synthase in grasses, at both the transcriptional and post-transcriptional levels to understand the molecular machinery and mechanisms by which MLG production and chain structure is regulated. Specifically, the results of a CRISPR/Cas9 gene editing strategy targeting CSLF6 regulatory regions will be presented as well as data from recent biochemical assays exploring functional reconstitution of the enzyme. Together, this knowledge will assist in breeding strategies aimed at elevating cereal grain soluble dietary fibre levels in the major crop wheat.
This work is supported by funding from the Australian Research Council (DP210102225).