Periwinkle Plants Provide Ammunition in the War on
April 26, 2010
A team of scientists from the
Agricultural Research Service (ARS) and
the University of Florida Indian River Research and Education
Center have turned an ornamental plant into a tool for combating a
bacterial disease that threatens the worlds citrus crop.
Periwinkle (Catharanthus roseus) has proved to be an effective
screening tool for treatments to control Huanglongbing (HLB), according to
Duan of the ARS
Horticultural Research Laboratory (USHRL) in Fort Pierce, Fla.
HLB, also known as citrus greening, is one of the most destructive diseases
of citrus worldwide. Caused by three closely related species of bacteria, there
is no known cure for HLB and no established effective treatments. It remains a
threat not only to the citrus industry in Florida, where it was discovered in
2005, but to citrus nationwide. The search for controls has been hampered in
part because infected citrus plants are difficult to regenerate and study.
Duan and his colleagues have found that periwinkle performs well as a
stand-in for citrus, becoming quickly infected with HLB bacterium and
responding well to antibiotic compounds tested to reduce infection. Duans
W. Turechek and
Stover, both at USHRL, and Mu- Qing Zhang, Lijuan Zhou and Charles A.
Powell of the University of Florida Indian River Research and Education Center.
The researchers used HLB-infected lemon trees to infect periwinkle plants by
way of dodder and then ran greenhouse experiments to find the optimal nutrient
and soil treatments for regenerating periwinkle with high infection rates. They
also soaked infected periwinkle cuttings in different chemical compounds and
found that two of them performed well as potential HLB treatments.
The team published the results in the journal Phytopathology. Duan
emphasized that the results are limited to greenhouse settings and that the
chemical compounds, penicillin G sodium and biocide
2,2-dibromo-3-nitrilopropionamide (DBNPA), must still be evaluated in field
trials and approved for use by regulatory agencies before commercial use is
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture (USDA). The
research supports the USDA priority of promoting international food security.