Understanding their function will assist in breeding plantation trees for better paper and timber products, and reduce our reliance on native forests.

CSIRO Plant Industry researchers, Dr Colleen MacMillan and Dr Simon Southerton, together with colleagues from the Australian National University (ANU), University of British Columbia (UBC) and other CSIRO Divisions, have found that particular fasciclin-arabinogalactan proteins (FLAs) affect the stiffness and strength of stems in both herbaceous (Arabidopsis) and woody plants (Eucalyptus trees). 

These FLA proteins contain a domain common to all organisms from bacteria to humans called the fasciclin domain that is very ancient. 

Until now it was unclear what these particular FLA proteins did in plants but the team discovered that they affect the biomechanics, architecture and synthesis of thick cell walls.

By deactivating the genes responsible for the production of the FLA proteins in the model plant Arabidopsis, the research team found that the plant stems were less stiff and less strong.

Similar correlations were seen in eucalypt stems, in which increased expression of the FLA genes occurred in cells that develop into very stiff and strong wood.

This discovery was published in a recent edition of The Plant Journal [external link].

Read other articles from the CSIRO Plant Industry newsletter.