S.A. Jobling
CSIRO Agriculture Flagship, Canberra Australia
Dietary fibre is largely derived from the cell walls of plants and in cereal grains, arabinoxylan and 1,3;1,4-β-D-glucan (betaglucan) are the major cell wall polysaccharides. Dietary fibre is an essential part of a healthy diet however fibre consumption in most Western countries is below target levels. Food products made from grains that have a high content of water soluble betaglucan such as oats and barley are allowed specific health claims in some countries related to the lowering of blood cholesterol. Wheat grain has only low levels of betaglucan, most of which is insoluble. The cellulose-synthase-like CslF6 gene is a major component of the betaglucan synthase and we will describe work to characterise the function of this protein from various cereals in Nicotiana benthamiana leaf expression system. Each CslF6 gene produces a betaglucan with a distinct structure and this affects water solubility. Overexpression of selected CslF6 genes in wheat grain increases levels of soluble betaglucan and dietary fibre.