Researchers Reveal Secret of Plant Dietary Fiber Structure

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.

A paper outlining the study appeared recently in Nature Communications journal

The team basically identified that a family of cell wall polymers called 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 fiber properties in nutrition, but also for applications in medicine, agriculture, and a range of other industries,” said Professor Mike Gidley, UQ Director of the Centre for Nutrition and Food Sciences.

As we know that plants don’t have a skeleton, like animals. Even without a skeleton plants can range from soft, floppy grasses to the majestic Eucalypt tree. The key difference lies in their cell wall fiber structures.

This amazing diversity of plant structures comes from three fundamental building blocks of plant fiber present on the cell wall, namely
1. Cellulose
2. Hemicellulose
3. Lignins

We know that lignins help in water-proofing whereas cellulose serves as rigid scaffolding material but we did not know about the chemical functions on hemicellulose.

Professor Gidley and Dr. Deirdre Mikkelsen, in collaboration with Dr. Francisco Vilaplana at KTH’s Wallenberg Wood Science Centre, experimented with two major components of hemicellulose.

“We tested the properties of cellulose when adding different proportions of the two components, and found that ‘mannans’ improved compression while ‘xylans’ drastically increase its stretchiness,” Dr Mikkelsen said.

“We generated modified cellulose material in the laboratory that could be stretched to twice its resting length — the equivalent to watching a wet sheet of paper being stretched to double its length without tearing.”

The team said its discovery had many applications, including in wound care and in the texture of plant foods. This research also creates a basis for new cellulose chemistry. It also possibilities for developing better, environmentally-sustainable plant-based materials

Journal Reference:
Jennie Berglund, Deirdre Mikkelsen, Bernadine M. Flanagan, Sushil Dhital, Stefan Gaunitz, Gunnar Henriksson, Mikael E. Lindström, Gleb E. Yakubov, Michael J. Gidley, Francisco Vilaplana. Wood hemicelluloses exert distinct biomechanical contributions to cellulose fibrillar networks. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-18390-z

Press Release: University of Queensland