ARS | Publication request: Prophages of “Candidatus Liberibacter asiaticus” and their distribution in southern China

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2011
Publication Date: June 24, 2011
Citation: Gao, Y., Chen, J., Deng, X. 2011. Prophages of “Candidatus Liberibacter asiaticus” and their distribution in southern China. American Phytopathological Society Abstracts. 101:S58.

Technical Abstract: “Candidatus Liberibacter asiaticus” is a putative pathogen of citrus Huanglongbing (HLB), a destructive citrus disease worldwide. Prophage is an important biological trait of bacteria including “Ca. L. asiaticus”. The role of prophages in bacterial virulence, environmental adaptation, strain specification and genome evolution has recently drawn the interest of the HLB research community. In this study, 12 consecutive open reading frames in a “Ca. L. asiaticus” prophage/phage reported in Florida were used as a reference to examine the presence of homologs in three different “Ca. L. asiaticus” strains in China. PCR analyses showed the amplification rates of 83.3% (10/12) for strain YN835, 33.3%(4/12) for strain GDws231, and 8.3% (1/12) for strain GDws217. All amplicons were sequenced and shared >98% similarity among corresponding homologs, with one exception. At this exceptional locus, strains YN835 and GDws231 showed high level of sequence heterogeneity with a gap of 140 bp. However, at the amino acid level, the two sequences were 100% comparable with 79% similarity (69% identity). This locus was not detected in strain GDws217. Results from this study show that there are at least three related but different prophages of “Ca. L. asiaticus” in southern China. Prophage YN835 is predominately in Yunnan Province. Prophage GDws217 and prophage GDws231 are found in Guangdong Province.