ABSTRACT
In the last 50 years, giant strides have been made in our understanding of cell wall biology in the Poaceae, which include our most important cereal crops. These achievements have been made possible by impressive and parallel advances in biotechnologies for defining the structures, biochemistry and cell biology of cell walls. In particular, the advent of DNA cloning technologies enabled us to quickly define the complete amino sequences of enzymes involved in wall synthesis and degradation, and opened the way for solving three-dimensional structures of key enzymes. Functional genomics technologies, supported by spectacular advances in computing power, enabled complete sets of expressed RNA transcripts, proteins and metabolites to be defined in single experiments. Despite these advances, important questions remain about the identities of genes and enzymic mechanisms that mediate (1,3;1,4)-β-glucan and heteroxylan synthesis and the biological roles of xyloglucan transglycosylases. Moreover, there is not yet agreement as to the sites of synthesis of several non-cellulosic wall polysaccharides. Sustained interest in cereals and grasses for feeding the burgeoning global population, as sources of renewable biofuels and in human health, continues to drive the development of exciting new technologies, including crucially important methods for harnessing beneficial natural and induced genetic variation.
