Onward From Mendel
A retooled gene in tomatoes controls ripening to give better flavor and shelf
If Gregor Mendel could see us now! Surely he'd be
delighted that his own discoveries about the inheritance of
traitsstemming from his experiments in the mid-1800s with garden
peashave become a foundation for modern genetics.
Perhaps he'd be impressed that, within the first year of the new millennium,
ARS scientists and their colleagues
worldwide expect to finish the first complete map of the genes of a green
planta mustard called Arabidopsis thaliana, or thale cress.
Granted, we selected this plant because of its relatively tiny genome. But
what we learn about the genes that control this plant's lifefrom
germination to fruitingwill help us discover the function of other genes
in thousands of plantsand other organisms.
We're also mapping genomes of rice, wheat, cotton, soybeans, corn,
sugarbeets, potatoes, tomatoes, and other crops. And we're not just delineating
existing genetic landscapes. We're moving useful genes from one species to
another to improve a food crop's adaptability, flavor, nutritional value, or
insect or disease resistanceor to dramatically improve in other ways the
plants we rely on for food, feed, or fiber or value for their beauty.
The new and burgeoning field of bioinformaticsalso known as
computational biologyis bringing together genetics, computer science, and
mathematics to answer questions about gene location, structure, and function.
By harnessing the computer's analytical power, we're searching for similarities
in genes of different organisms. We'd bet Mendel would well understand how such
similarities could speed the discovery of genes that control prized traits.
With a dozen new automated DNA analyzers, we hope to reveal gene sequences
in days instead of weeks, months, or years.
We'd tell Mendel how we help run the publicly accessible computer catalogs
of plant genes. He could "surf the web" to the GrainGenes
databasea treasury of genes of wheat, barley, and other grains. Or
SolGenes, the world's most comprehensive genome database for solanaceous crops
like tomatoes, peppers, and potatoes.
Once he'd had a chance to take this all in, we would expectwould hope
forsome suggestions. Objective scrutiny, after all, is essential to the
scientific investigations of every era.
Though fun to imagine, Mendel of course cannot visit our labs, given that he
died in 1884. It wasn't until the first year of a new
century1900that his discoveries of the natural laws of heredity
began to become generally known. But today, 100 years later, the determination,
dedication, and sense of wonder that characterized Mendel and other early
geneticists are still alive and well in ARS laboratories.By
Marcia Wood, Agricultural
Research Service Information Staff.
This research is part of Plant, Microbial, and Insect Genetic Resources,
Genomics, and Genetic Improvement, an ARS National Program (#301) described on
the World Wide Web at http://www.nps.ars.usda.gov/programs/cppvs.htm.
For details on ARS plant genomics projects, contact
Peter K. Bretting, National Program
Leader for Plant Germplasm, USDA-ARS National Program Staff, 5601 Sunnyside
Ave., Beltsville, MD 20705-5139; phone (301) 504-5541, fax (301) 504-4663.
"Onward From Mendel" was published in the
December 1999 issue of
Agricultural Research magazine.