Secret of plant dietary fibre structure revealed

Bacterial cellulose: scanning electron micrograph of a cellulose fibre network produced by the bacterial cellulose model © University of Queensland. The secret of how fibre shapes the structure of plant cell walls has been revealed, with potentially wide-ranging applications ranging from nutrition and health to agriculture. Researchers from The University of Queensland and KTH Royal Institute of Technology in Sweden have uncovered the mechanics of how plant cell walls balance the strength and rigidity provided by cellulose with its ability to stretch and compress. UQ Director of the Centre for Nutrition and Food Sciences Professor Mike Gidley said the team identified that a family of cell wall polymers - hemicelluloses - played a critical role in balancing the need for rigidity with the flexibility to bend without breaking. "This discovery is important for understanding dietary fibre properties in nutrition, but also for applications in medicine, agriculture and a range of other industries,' Professor Gidley said. "Plants don't have a skeleton, and their structures can range from soft, floppy grasses to the majestic architecture of a Eucalypt tree, with the key differences lying in their cell wall fibre structures.' The diversity of plant structures results from the three core building blocks of plant fibre - cellulose, hemicellulose and lignins - in the plant cell walls. "Lignins provide the water-proofing in woody fibre and cellulose is the rigid scaffolding material in almost all plant types, but the mechanical function of hemicellulose was something of a mystery,' Professor Gidley said.