| 
ARS scientists have sequenced the genome of the
bacteria that causes citrus greening, a disease that threatens the nations's
$2.2 billion citrus industry.Click the image for more information about
it.
|
|
|
ARS Scientists Sequence Citrus Disease Bacterium
By Dennis
O'Brien
February 12, 2009 Researchers have a new tool
to combat citrus Huanglongbing (HLB), a disease threatening the nation's $2.2
billion citrus industry.
Agricultural Research Service (ARS)
scientists have sequenced the genome of the bacterium Candidatus
Liberibacter asiaticus, which causes HLB. The bacterium resides in the plant's
phloem tissues, affecting the passage of nutrients and eventually killing the
plant.
Plant pathologist
Yong-Ping
Duan and research leader
David
Hall, at the ARS
U.S.
Horticultural Research Lab in Fort Pierce, Fla., have sequenced more than
95 percent of the bacterium's genome and have posted results in GenBank, an
online database of genetic resources. They are currently sequencing the
remaining 5 percent and plan to publish a paper describing what the genome
reveals about the bacterium's taxonomy, evolution and some of its enzymatic
pathways.
Sequencing the genome should allow scientists to decipher the bacteria's
genetic code, study its biological features more closely and unlock mysteries
about how it spreads disease. Researchers also should be able to identify genes
that play roles in disease development to help design control strategies.
The bacterium is transmitted from plant to plant by the Asian citrus psyllid
(Diaphorina citri), a tiny brown insect that feeds on all kinds of
citrus crops. Duan and Hall found sufficient target bacterial DNA for
sequencing by searching among infected psyllids.
The disease, also known as citrus greening, occurs in Asia, India, Africa
and South America, and was discovered in Florida in 2005. Plants can be
infected for two years before characteristic yellow shoots and mottled leaves
begin to appear. Infected trees produce unmarketable, bitter fruit and usually
die in five to seven years.
Find out more about ARS research on citrus greening at:
http://www.ars.usda.gov/citrusgreening/
ARS is the principal intramural scientific research agency in the
U.S. Department of Agriculture.
Printable Version
E-mail this page
