Cotton 'Gold Standard' Genome Ready

Cotton evolution tracked from wild species to domestic species in textile production today.

Published on: Jan 31, 2013

In the Dec. 20 edition of the journal Nature, an international group of researchers from 31 institutions presents a high-quality draft assembly of the simplest cotton genome—known scientifically as Gossypium raimondii.

This ancestral species indigenous to the Americas was compared to several other sets of cotton data contributed by the U.S. Department of Agriculture.

Why do it? The researchers now can trace the evolution of cotton over millions of years from wild varieties to the domesticated species now used in textile production.

The effort to develop a gold standard sequence of the cotton genome was jump-started in 2007 when the U. S. Department of Energy Joint Genome Institute Community Sequencing Program approved a proposal from UGA Regents Professor Andrew Paterson.

Cotton Gold Standard Genome Ready
Cotton 'Gold Standard' Genome Ready

Cotton genome
Among the 74 authors of the paper, 18 were from UGA, the largest among the 31 institutions involved. Other contributors were from USDA, Cotton Inc., Iowa State University, Mississippi State University, the Consortium for Plant Biotechnology Research and the National Science Foundation.

"My group set out toward this goal in 1991, and this achievement is not an ending but a beginning," Paterson said. "We are enthusiastically pursuing the next steps using the genome sequence to better understand cotton biology and identify important genes that will improve sustainability of cotton production and increase its role in the more bio-based economy of the future."

The DOE hopes to maximize cotton's potential as a biofuel stock while developing more efficient and sustainable crop varieties for the fiber's traditional uses.

Cotton fiber
This new "cotton data will help accelerate the study of gene function, particularly cellulose biosynthesis, the understanding of which is fundamental to improved biofuels production," said Jeremy Schmutz, head of the DOE Joint Genome Institute Plant Program and a faculty investigator at the HudsonAlpha Institute for Biotechnology. Schmutz led the effort to sequence and assemble the genome for the Joint Genome Institute.  "In addition, the unique structure of the cotton fiber makes it useful in bioremediation, and accelerated cotton crop improvement also promises to improve water efficiency and reduce pesticide use."

The worldwide cotton community chose G. raimondii to be the first of 50 cotton species sequenced as the best model for the New World progenitor of commercially important upland and pima cottons.

In collaboration with Mississippi State University and the USDA's Agricultural Research Service, Paterson and others selected several additional genomes for sequencing, which enabled the team to trace cotton's evolution and the gene duplications that accelerated fiber development.

On the farm, the identification of key cotton genes and their importance will provide data crucial to increasing cotton production, quality and sustainability. In the lab, the comparison of an elite cotton cultivar to its wild ancestors provides new insights into how a polyploid—a hybrid of more than one type of cotton—becomes more than the sum of its ancestors. All flowering plants have experienced polyploidy, a process by which the entire hereditary blueprint of an organism is doubled.

Paterson's colleagues built their understanding of this complexity based on information accumulated over more than 20 years of research funded by the NSF, the USDA, Cotton Inc., the Consortium for Plant Biotechnology Research, Bayer Crop Science and other public and private agencies.

Melancon is a news editor with the University of Georgia College of Agricultural and Environmental Sciecnes.