Scientists discover genes to better grass to energy production

Scientists from the Biotechnology and Biological Sciences Research Council (BBSRC) Sustainable Bioenergy Centre (BSBEC) have uncovered a series of genes which could help grasses being breed with better characteristics for bioenergy production.

The genes help to better develop the wood part of the grass, called the fibrous, such as what is in rice and wheat. In understanding how these genes operate, the scientists hope to be able to discover how to breed crops so that they need less energy to turn them into biofuels.

Most of the energy in the plants is stored in the woody part but it is difficult to access this energy. However, the researchers discovered that they could create multi-use crops where the straw could be used to create energy more efficiently.

They say that this is essential in order to create energy in a sustainable manner without competing with food.

Professor Paul Dupree, from the University of Cambridge, explains: ‘Unlike starchy grains, the energy stored in the woody parts of plants is locked away and difficult to get at. Just as cows have to chew the cud and need a stomach with four compartments to extract enough energy from grass, we need to use energy-intensive mechanical and chemical processing to produce biofuels from straw.’

He continues: ‘What we hope to do with this research is to produce varieties of plants where the woody parts yield their energy much more readily - but without compromising the structure of the plant. We think that one way to do this might be to modify the genes that are involved in the formation of a molecule called xylan - a crucial structural component of plants.’

It is this xylan that makes up the wall that surrounds the plants’ cells, holding molecules in place so that the plant stays tough. It is this that needs to be broken down in order to access the energy more efficiently.

However, grasses have a different type of xylan when compared to other plants and the scientists wanted to discover what this difference was. They searched for the genes that were switched on more readily in grasses and found the gene family in wheat and rice, which was called GT61, which they could use to give the grass a form of xylan.

Rowan Mitchell of Rothamsted Research adds:  ‘As well as adding the GT61 genes to Arabidopsis, we also turned off the genes in wheat grain. Both the Arabidopsis plants and the wheat grain appeared normal, despite the changes to xylan. This suggests that we can make modifications to xylan without compromising its ability to hold cell walls together. This is important as it would mean that there is scope to produce plant varieties that strike the right balance of being sturdy enough to grow and thrive, whilst also having other useful properties such as for biofuel production.’

The research was conducted by the University of Cambridge and Rothamsted Research, which receives funds from the BBSRC.