RESEARCH
L
ike the blueprint of a home showing all its support beams, plumbing and wiring, the genetic information carried in the cells of all living things provide information about the growth, development and persistence of those organisms. Boiled down to its basic building blocks, the deoxyribonucleic acid (DNA) of every human, plant, animal or microbe consists of four chemical components called nucleotides, which are denoted A, T, C and G. These molecules are grouped into segments called genes, which are the basic units of heredity. Genes direct the production of proteins and other molecules that ultimately define things such as how an organism looks, how it moves and how it responds to changes in its environment. To have access to the complete sequence of an organism is like being given an instruction manual for the construction of that form of life. Scientists mine these genetic sequences to learn such things as how bacteria cause disease because unlocking the genetic cues that lead to sickness can also reveal the key to prevention. Scientists hope the same will hold true for the production of biofuels; that by unraveling the information trapped in the DNA of various bioenergy feedstocks or the organisms associated with them, researchers will uncover the means to improve or optimize these feedstocks or to identify better enzymes for degrading cellulose and hemicellulose or for converting biomass into fuels. The genomes of several organisms linked to biofuels production have already been sequenced including the poplar tree and the microbes found in the termite gut. Now, researchers report the results of two sequencing efforts—one to sequence the corn genome and one to sequence a fungus that plays a pivotal role in the growth and productivity of the poplar tree.
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‘The first draft of the genome sequence is exciting because it’s the first comprehensive glimpse at the blueprint for the corn plant. Scientists now will be able to accurately and efficiently probe the corn genome to find ways to improve breeding and subsequently increase crop yields, and resistance to drought and disease.’
Corn’s Genetic Blueprint The effort to sequence the corn genome was initiated in the late 1990s. At this time, the National Corn Growers Association worked with Sen. Kit Bond, R-Mo., to advocate for the establishment of the National Plant Genome Initiative. This research program was ultimately established in 1998 with the long-term aim of exploring the structure and function of the DNA of certain plants, including corn. However, the sequencing technology available in the late 20th century was not advanced enough to deal with the corn genome. “The corn genome is as big as the human genome but more complex,” explains Patrick Schnable, a geneticist at Iowa State University who has been studying the
ETHANOL PRODUCER MAGAZINE JUNE 2008