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POSTERS: Proteomics / metabolomics / genomics

Host range and molecular characterization of two novel Ralstonia phages - RsoP1EGY and RsoP1IDN
Qi Huang - Floral and Nursery Plants Research Unit, US National Arboretum, USDA/ARS. Hardian Addy- Floral and Nursery Plants Research Unit, US National Arboretum, USDA/ARS, Abdelmonium Ali Ahmad- Department of Plant Pathology, Faculty of Agriculture, Minia University, Abdelmonium Ali Ahmad- Floral and Nursery Plants Research Unit, US Nati

Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating bacterial diseases in tropical, subtropical, and temperate regions of the world. Two lytic R. solanacearum-infecting phages isolated from soil in Egypt and Indonesia, respectively, were characterized in this study. They were designated Ralstonia phage RsoP1EGY and RsoP1IDN based on our phage identifier naming approach to reflect the phages’ bacterial host species, characteristics and origins. Both phages have typical podovirus morphology and are similar in genome size. They are different, however, in host specificity and share no sequence homology. Genomic analysis revealed that phage RsoP1EGY has a dsDNA genome of 41,297 bp, contains 50 annotated open reading frames and has no significant sequence identity to any other reported phages. Phage RsoP1IDN has a linear dsDNA genome of 41,135 bp with 413-bp terminal repeats, and 41 open reading frames. The genome of RsoP1IDN was most closely related to that of Ralstonia phage RSB1, but different in that it contains a putative HNH homing endonuclease. When tested for host specificity, phage RsoP1EGY specifically infected only race 3 biovar 2 phylotype IIB sequevar 1, not non-race 3 biovar 2 strains of R. solanacearum, while phage RsoP1IDN had a narrow host range infecting only 3 out 16 tested strains. RsoP1EGY and RsoP1IDN are the first sequenced and characterized R. solanacearum phages isolated from Egypt and Indonesia respectively.