title: Differential Colonization Dynamics of Cucurbit Hosts by Erwinia tracheiphila.
abstract: Bacterial wilt is one of the most destructive diseases of cucurbits in the Midwestern and Northeastern United States. Although the disease has been studied since 1900, host colonization dynamics remain unclear. Cucumis- and Cucurbita-derived strains exhibit host preference for the cucurbit genus from which they were isolated. We constructed a bioluminescent strain of Erwinia tracheiphila (TedCu10-BL#9) and colonization of different cucurbit hosts was monitored. At the second-true-leaf stage, Cucumis melo plants were inoculated with TedCu10-BL#9 via wounded leaves, stems, and roots. Daily monitoring of colonization showed bioluminescent bacteria in the inoculated leaf and petiole beginning 1 day postinoculation (DPI). The bacteria spread to roots via the stem by 2 DPI, reached the plant extremities 4 DPI, and the plant wilted 6 DPI. However, Cucurbita plants inoculated with TedCu10-BL#9 did not wilt, even at 35 DPI. Bioluminescent bacteria were detected 6 DPI in the main stem of squash and pumpkin plants, which harbored approximately 10(4) and 10(1) CFU/g, respectively, of TedCu10-BL#9 without symptoms. Although significantly less systemic plant colonization was observed in nonpreferred host Cucurbita plants compared with preferred hosts, the mechanism of tolerance of Cucurbita plants to E. tracheiphila strains from Cucumis remains unknown.
authors.affiliation: First, second, and fourth authors: Department of Plant Pathology, and second and third authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691.
authors.forename: Cláudio M
authors.initials: CM
authors.lastname: Vrisman
authors.affiliation: First, second, and fourth authors: Department of Plant Pathology, and second and third authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691.
authors.forename: Loïc
authors.initials: L
authors.lastname: Deblais
authors.affiliation: First, second, and fourth authors: Department of Plant Pathology, and second and third authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691.
authors.forename: Gireesh
authors.initials: G
authors.lastname: Rajashekara
authors.affiliation: First, second, and fourth authors: Department of Plant Pathology, and second and third authors: Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691.
authors.forename: Sally A
authors.initials: SA
authors.lastname: Miller
mesh_terms: D028462:Cucumis / Q000382:microbiology*; D028464:Cucurbita / Q000382:microbiology*; D004885:Erwinia / Q000472:pathogenicity / Q000502:physiology*; D018014:Gene Transfer Techniques; D058507:Host Specificity; D008163:Luminescent Measurements; D010957:Plasmids