Papaya's Genome Unmasked by ARS Scientists,
By Marcia Wood
April 23, 2008
Smooth, sweet papaya, one of America's
most popular tropical fruits, has now surrendered some of its genetic secrets.
Agricultural Research Service (ARS)
scientists and others in a University of
Hawaii-led venture have uncovered the structure or sequence of the genes
and other genetic material that make up papaya's genome.
An article in the journal Nature reports details
of their accomplishment, which represents the first time the genome of a
genetically engineered crop has been sequenced. That's according to
Gonsalves, director of the ARS
Pacific Basin Agricultural Research Center at Hilo, Hawaii. He's also an
author of the journal article.
"SunUp," the red-fleshed papaya chosen for the investigation, was
developed in research that Gonsalves began in 1985. Working at that time for
New York State Agricultural Experiment
Station in Geneva, Gonsalves collaborated with scientists from ARS, the
University of Hawaii-Manoa, and Michigan-based Pharmacia Company to create the
The scientists genetically engineered SunUp plants to activate a
geneharmless to humansthat enables the papaya to resist attack by
papaya ringspot virus. Starting in 1992, papaya ringspot disease, caused by the
virus, threatened to destroy Hawaii's papaya plantations.
SunUp was used as a parent of a yellow-fleshed, virus-resistant papaya
called "Rainbow." Made available to growers in 1998, Rainbow became
Hawaii's leading commercial papaya.
Further scrutiny of the newly available SunUp genomic data is expected to
speed identification of papaya genes that control prized traits such as flavor,
texture, aroma, nutritional value, or resistance to insects and other pests.
Former ARS scientists Henrik H. Albert and Paul C. Moore are among the other
authors of the Nature article. Maqsudul Alam of the University of
Hawaii-Manoa led the genome exploration.
Papayas are rich in vitamins A and C and are a good source of potassium, an
ARS is the U.S. Department of
Agriculture's chief scientific research agency.