(AFP) – Feb 17, 2008
PARIS (AFP) — Agricultural scientists in the United States have identified a key gene that determines oil yield in a corn, a finding that could have repercussions for the fast-expanding biofuels industry.
The gene lies on Chromosome 6 of the maize genome, according to a paper published on Sunday by Nature Genetics.
It encodes a catalysing enzyme called DGAT1-2, which carries out the final step in the plant's oil-making process.
In addition, a tiny amino acid variant within this gene can boost the yield of oil and oleic acid -- the sought-after edible fat in corn -- by up to 41 percent and 107 percent respectively.
The paper, written by a team from the US chemicals and agribusiness giant DuPont, was based on a comparison of 71 strains of maize whose oil content ranged from low to high.
DGAT is "a promising target for increasing oil and oleic-acid contents in other crops," say the authors, led by Bo Shen of DuPont unit Pioneer Hi-Bred International, in Johnston, Iowa.
Present-generation biofuels are derived from food crops such as corn, sugar cane and soybeans.
Initially viewed as an environmentally-friendly alternative with no geopolitical risk compared with dirty fossil fuels, biofuels are now under attack as some unintended consequences emerge.
The impacts include higher prices in the global food market as more fields are devoted to growing fuel rather than food, and the destruction of forests in Brazil and Indonesia as land is cleared for fuel crops.
Scientists are looking at ways of boosting output from existing biofuel crops by adding the promise a higher yield in oil. Proposed methods include classic cross-breeding as well as genetic engineering, a technology that remains fiercely opposed in some countries.
Another avenue of exploration for biofuel production is in non-food fibrous plants and cellulose materials, such as switchgrass, wood chips and straw. But these novel sources, hampered by costs and technical complications, are struggling to reach commercial scale.
Global biofuel production tripled from 4.8 billion gallons (18.16 billion litres) in 2000 to about 16 billion gallons (60.56 billion litres) in 2007, but still accounts for less than three percent of the global transport fuel supply, according to US Department of Agriculture figures.
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