Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2004
Publication Date: 6/1/2004
Citation: Baliji, S., Black, M.C., French, R.C., Stenger, D.C., Sunter, G. 2004. Spinach curly top virus: a new curtovirus species revealing a history of recombination among curtoviruses. American Phytopathological Society Abstracts. Phytopathology 94:S6. Interpretive Summary:
Technical Abstract: A curtovirus of spinach was isolated in southwest Texas during 1996. Disease symptoms included severe stunting and chlorosis, with younger leaves curled, distorted, and dwarfed. Symptoms produced in spinach agroinoculated with cloned viral DNA were similar to those observed in the field. Viral single-stranded and double-stranded DNA forms typical of curtovirus infection were detected in both field-collected and experimental host plants by Southern blot hybridization. The complete nucleotide sequence of the infectious clone comprised 2925 nucleotides, with seven open reading frames encoding proteins homologous to those of other curtoviruses. Complete genome comparisons revealed that the spinach curtovirus shared 64.2-83.9% nucleotide sequence identity relative to four previously characterized curtovirus species: Beet curly top virus, Beet severe curly top virus, Beet mild curly top virus, and Horseradish curly top virus. Phylogenetic analysis of individual open reading frames indicated that the evolutionary history of the three virion sense genes was different from that of the four complementary sense genes, suggesting that recombination among curtoviruses may have occurred. Collectively, these results indicate that the spinach curtovirus characterized here represents a new species of the genus Curtovirus, for which we propose the name Spinach curly top virus.