Wheat arabinoxylans: Exploiting variation in amount and composition to develop enhanced varieties

Arabinoxylans (AX) are the major polymers of wheat grain cell walls. The content and the structure of AX polymers show large differences between tissues and between wheat cultivars that affect the end-use properties and nutritional quality of the grain. The development of new wheat cultivars with enhanced quality, therefore, requires methods to exploit this variation and it is essential to understand and modulate the mechanisms controlling the key events of cell-wall polymer synthesis. This paper summarises recent knowledge on the structure and physicochemical properties of AX including variation between cultivars and tissues, methods for analysis and screening, biosynthetic mechanisms and approaches to identifying key genes. This knowledge is essential to understand AX properties and defined possible targets for plant breeding.