Identification of domains of the Tomato spotted wilt virus NSm protein involved in tubule formation, movement and symptomatology.
Deletion and alanine-substitution mutants of the Tomato spotted wilt virus NSm protein were generated to identify domains involved in tubule formation, movement and symptomatology using a heterologous Tobacco mosaic virus expression system. Two regions of NSm, G(19)-S(159) and G(209)-V(283), were required for both tubule formation in protoplasts and cell-to-cell movement in plants, indicating a correlation between these activities. Three amino acid groups, D(154), EYKK(205-208) and EEEEE(284-288) were linked with long-distance movement in Nicotiana benthamiana. EEEEE(284-288) was essential for NSm-mediated long-distance movement, whereas D(154) was essential for tubule formation and cell-to-cell movement; indicating separate genetic controls for cell-to-cell and long-distance movement. The region I(57)-N(100) was identified as the determinant of foliar necrosis in Nicotiana benthamiana, and mutagenesis of HH(93-94) greatly reduced necrosis. These findings are likely applicable to other tospovirus species, especially those within the 'New World' group as NSm sequences are highly conserved.
Li
Weimin
W
University of Florida, Citrus Research and Education Center, Lake Alfred, FL 33850, USA.
Lewandowski
Dennis J
DJ
Hilf
Mark E
ME
Adkins
Scott
S
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D008969:Molecular Sequence Data; D009068:Movement; D016296:Mutagenesis; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017434:Protein Structure, Tertiary; D011523:Protoplasts / Q000821:virology; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000821:virology; D017865:Tospovirus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*
D017931:DNA Primers; D053830:Plant Viral Movement Proteins; D017361:Viral Nonstructural Proteins