La Jolla, California
July 31, 2003

A Salk Institute study provides significant new information in the process of allowing scientists to understand the function of plant genes. The study is published in the August 1 issue of Science.

Salk professor Joseph Ecker and his team worked on the common mustard seed plant Arabidopsis-the first plant to have its entire genome sequenced by a consortium that included Ecker and other
scientists throughout the world-to focus on the complex issue of how genes function.

"Sequencing is just the beginning of understanding how any organism functions," said Ecker. "Once
the Arabidopsis genome was sequenced, we asked how many of the plant's approximately 25,000
genes have people actually worked on. Less than 10 percent have been touched by any scientist."

Ecker and his team used Agrobacterium T-DNA insertions into the genes of Arabidopsis to identify
mutations in two-thirds (approximately 21,000 of 25,500) of all Arabidopsis genes, providing the largest
collection of sequenced mutations known for any higher multi-cellular organism.

"The availability of the complete genome sequence and new technologies have made possible what
we believe is the definitive study of this issue. These results provide significant new information in both
the areas of functional genomics and basic plant biology," said Ecker.

As part of the study, Ecker and his colleagues focused on unraveling the precise molecular pathway
that governs how ethylene gas works in plants. For agriculture, ethylene gas is a vital chemical
messenger important for such processes as fruit ripening and how plants respond to pathogenic
organisms.

To share their findings with other researchers, Ecker and his team have developed a public database
(signal.salk.edu). The database, containing more than 120,000 sequenced-indexed gene mutations
and their corresponding mutants, is unprecedented for any model organism. Using a simple search of
the database now allows scientists worldwide to identify a plant mutant in virtually any gene, thus
dramatically increasing the way plant biologists study a particular gene.

"The information you get from Arabidopsis is very likely to be immediately applicable to all plants," said Ecker. "The information that we produce will be used by a range of people to improve plant growth, yield, and drought tolerance."

This work was supported grants from the National Science Foundation Arabidopsis 2010 Project and
by the Department of Energy.

The Salk Institute for Biological Studies, located in La Jolla, Calif., is an independent nonprofit dedicated to fundamental discoveries in the life sciences, the improvement of human health and conditions, and the training of future generations of researchers. The institute was founded in 1960 by Jonas Salk, M.D., with a gift of land from the City of San Diego and the financial support of the March of Dimes Birth Defects Foundation.