Some plants naturally make readily degradable lignin

25 October 2016

Researchers from the University of Auckland Schools of Biological Sciences and Chemical Sciences have recently collaborated with the Great Lakes Bioenergy Research Centre (GLBRC) in a study led by University of Wisconsin-Madison biochemistry professor John Ralph. The study concerned the structure of lignin, an important molecule that occurs in the cell walls of plants. Lignin is of crucial importance in industry as it prevents associated cell wall polysaccharides from being broken down in the production of second-generation biofuels. In 2014, Professor Ralph and his colleagues made a major breakthrough in producing plants with a designer lignin – referred to as zip-lignin – that could be readily degraded chemically. This was done by introducing an exotic gene into the plants. The gene encodes an enzyme that introduces readily degradable components into lignin.

The present study, just published in Science Advances, reports the surprising finding that several groups of plants naturally produce these zip-lignins, although in small amounts. One of these plant groups, the commelinid monocotyledons, includes grasses, cereals and many other important economic plants. This plant group was first identified as a group many years ago by study collaborator Professor Philip Harris from the School of Biological Sciences. The findings from the present study open the way to more efficient production of second-generation biofuels.