An international team of scientists from Brazil and the United States have completed the draft genome sequences of two strains of the Xanthomonas bacteria that cause citrus canker. Citrus canker, a belligerent disease that has plagued plant growers in parts of the United States, South America, and Asia, causes millions of dollars in lost revenue every year for farmers of citrus crops such as oranges, limes, and grapefruit. The genomic information obtained by these sequencing projects, which is described in the journal BMC Genomics*, suggests possible intervention targets for further experimental investigation.
Joo Setubal, Associate Professor at the Virginia Bioinformatics Institute and the Department of Computer Science at Virginia Tech, commented: "Citrus canker, which is found in different citrus plants, is effectively a single disease that is spawned by one of three strains of certain species of the Xanthomonas bacterium. The genome sequence of the most virulent of the citrus canker pathogens, Xanthomonas citri subsp. citri, was completed in 2002, and this was a big step forward in understanding the disease. The two new sequences will provide a welcome boost to citrus canker studies."
Citrus canker has proved difficult to combat despite concerted national disease eradication efforts. The disease produces lesions, blisters, and holes in the stems, leaves, and fruit of citrus crops. While the bacterial infection of the plant is not harmful to humans, the fruit becomes damaged and infection can lead to leaf loss and premature dropping of fruit. The availability of the genome sequences for the two additional bacterial strains that cause citrus canker means that scientists can now use key similarities and differences between the three related genomic sequences to zero in on the molecular basis of citrus canker.
Leandro Moreira of the Federal University of Ouro Preto, Brazil, remarked: "There is currently no
|Contact: Barry Whyte|