Humans are attempting a second massive transformation of the plant kingdom. The first was the painstaking domestication of wild plant species for food: over millennia, farmers turned small seeds and fruits into the grocery-store sized beauties we know today. Biting into a peach is the end result of 4,000 years of careful breeding and cultivation. Humans have spent millennia reshaping the genetics of a wild fruit tree from China into the fruit in our grovestands.
This time it’s trees that grow on marginal soils while yielding a rich harvest of cellulose and other carbohydrates to convert into ethanol. One of the main stumbling blocks is a compound called lignin, the molecular “glue” holding together plant cells and hindering the production of biofuels. Until we can grow trees better suited for biofuel, the promise of so-called second-generation biofuels from woody biomass–not just sugars and oils from (often edible) plants–will be tough to realize.
Now, scientists are identifying genes with modern genetics that will let us design trees for this purpose. Publishing in the journal Nature Genetics, scientists in the International Peach Genome Initiative (IPGI), have published the 265-million base genome of the Lovell variety of Prunus persica, and started unraveling the genes that may unlock the potential of biofuels from trees.
By comparing the genome among 141 peach families with other plant species, researchers are mapping the unique metabolic pathways for key factors in producing biofuel. As it turns out, peaches, a close relative of poplar and other promising biofuel species, turn out to be model species to study how we might design new types of trees for energy. The fast-growing poplar, nicknamed the “DOE tree” for its central role in the Department of Energy’s cellulosic research program, is one of the targets of the recent peach research:
“One gene we’re interested in is the so-called ‘evergreen’ locus in peaches, which extends the growing season,” said Daniel Rokhsar, DOE JGI Eukaryotic Program head in a statement by Nature. “In theory, it could be manipulated in poplar to increase the accumulation of biomass.”