Cited research: PLoS Genet. 6, e1000943 (2010)

Poplar trees may not be the first plants to spring to mind when thinking of biofuels, but they are a potentially important feedstock, partly because they can grow on soils unsuitable for food crops.

To see how poplar growth could be improved, Daniel van der Lelie at the Brookhaven National Laboratory in Upton, New York, and his colleagues analysed the genome and metabolites of the microbe Enterobacter sp. 638, which lives naturally inside poplars and increases the plant's growth by as much as 40%.

Among the key genes identified in the bacterium are those encoding enzymes involved in the production of plant growth hormones. This hormone production depends, in turn, on the presence of compounds such as sucrose synthesized by the plant, showing how much the bacterium and tree depend on each other. L.O.-S.