Analysis of a prophage gene frequency revealed population variation of Las.pdf

Analysis of a Prophage Gene Frequency Revealed Population Variation of ‘Candidatus Liberibacter asiaticus’ from Two Citrus-Growing Provinces in China Rui Liu, Pei Zhang, Xuelian Pu, and Xiaoqian Xing, Laboratory of Huanglongbing Research, Department of Plant Pathology, South China Agricultural University, Guangzhou, Guangdong, P.R. China; Jianchi Chen, Crop Diseases, Pests and Genetics Research, San Joaquin Valley Agricultural Sciences Center, United States Department of Agriculture, Parlier, CA; and Xiaoling Deng, Laboratory of Huanglongbing Research, Department of Plant Pathology, South China Agricultural University Abstract Liu, R., Zhang, P., Pu, X., Xing, X., Chen, J., and Deng, X. 2011. Analysis of a prophage gene frequency revealed population variation of ‘Candidatus Liberibacter asiaticus’ from two citrus-growing provinces in China. Plant Dis. 95:431-435. Prophages are important genetic elements of bacterial genomes and are (38/39) in Yunnan (altitude 2,000 m). The difference was highly sig- involved in lateral gene transfer, pathogenicity, environmental adapta- nificant (P 0.0001) based on 2 analysis. However, the partial pro- tions, and interstrain genetic variability. In this study, the sequence of a phage terminase gene sequences obtained from 10 Guangdong strains prophage terminase gene of ‘Candidatus Liberibacter asiaticus’, a and 6 Yunnan strains were identical or highly similar, suggesting that at bacterium associated with citrus Huanglongbing (HLB), was selected least some bacterial strains in the two locations shared a common re- as a molecular marker to assess the genetic variation in two ‘Ca. L. cent origin. This is the first report on population variation of ‘Ca. L. asiaticus’ populations from geogr