www.checkbiotech.org ; www.raupp.info ; www.czu.cz

The cassava, a root similar to a potato that is grown mainly in South
America and Africa, has been chosen to have its genome sequenced by
researchers, including a UA scientist, for humanitarian and energy purposes
by the U.S. Department of Energy Joint Genome Institute, February 2007 by
Jeffrey Javier.

The UA, which played a major role in sequencing the genome of rice, is
providing one of the multi-institutional team's main researchers, Steven
Rounsley, associate research professor for BIO5 Institute and the Department
of Plant Sciences, with a place to study the cassava genome in the newly
opened BIO5 building.

"The cassava is a very important crop for subsistence farmers in Africa, and
to obtain more information that farmers can use will help them build better
crops for the poorest people," said Vicki Chandler, director of the BIO5
Institute.

The cassava, which is second to rice in the developing world as a main
source of food, has a unique potential for conversion into ethanol because
of its high percentage of starch, Rounsley said.

Interest in the cassava from the science community is still small, Rounsley
said, but since the U.S. Department of Energy's Bioenergy Initiative, the
government has taken interest in bioenergy and turning things like corn or
other starchy material into ethanol fuel.

"The cassava is not generally an interesting crop for the scientific
community, but the recent energy proposal kicked it all together and there
is a reality for a potential energy use," Rounsley said.

Despite the interests in ethanol fuel, the future of converting the starch
in the cassava into ethanol is still unsure, and it will be a long-term
research process before they come up with future uses such as alternative
fuel, Rounsley said.

But for billions of people in developing countries, the cassava is part of a
daily diet. From a humanitarian perspective, the cassava genome sequencing
project will benefit those people who eat it on a daily basis.

"The problem with the cassava is that it's so full of starch. There is very
little in nutrition," Rounsley said. "Protein is missing and there is a
cyanide compound in raw cassava that makes it poisonous to eat."

In sequencing the cassava genome, there are hopes to make it more nutritious
and safer to consume, and to protect the root from disease.

"Plant diseases can wipe out entire crops, and if this happens to a farmer
in Africa he not only loses his source of income, but also his food source
and the food source of the community," Rounsley said.

Africa and South America are one of the largest producers of cassava because
the root can survive draught conditions and can grow in poor soil, Rounsley
said.

"The cassava is a major crop in Latin America, and the cassava is not a
trivial crop, and the genome sequence of the cassava will be helpful in
identifying ways to improve the crop," said Robert Leonard, head of the
plant sciences department.

The sequencing project is still in the pilot phase, said Rounsley, meaning
the DOE is still evaluating the data to pick the next step.

After the DOE has completed evaluating the data, the information will be
passed on to researchers such as Rounsley to interpret and evaluate the data
and find a meaning.

"Sequencing a genome is like reorganizing a textbook where the chapters,
words and sentences are all mixed up," Rounsley said. "I try to define a
beginning and end to come to a meaning."

It takes about a year to generate a DNA sequence, and the resulting genome
can have a DNA sequence 800 million letters long, which is the same amount
as a grain of rice, Rounsley said.

"In terms of getting useful information to breeders, farmers and scientists,
we will try to get it to them as quickly as possible, but it may take one to
three years," Rounsley said.

In January, the UA was ranked No. 1 in agricultural sciences and No. 4 in
botany and plant biology, according to the Faculty Scholarly Productivity
Index, which is based on faculty scholarly activity.

"The UA is very strong in plant genetics and genomics," Chandler said.
"Steve is a really good addition and builds strength in our plant genomics
research."

[media.wildcat.arizona.edu]