Characterization of Tomato spotted wilt virus NSm protein domains involved in tubule formation, movement and symptoms

Authors: LI, WEIMIN; LEWANDOWSKI, DENNIS; Hilf, Mark; Adkins, Scott

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/7/2009
Publication Date: 7/26/2009
Citation: Li, W., Lewandowski, D.J., Hilf, M.E., Adkins, S.T. 2009. Characterization of Tomato spotted wilt virus NSm protein domains involved in tubule formation, movement and symptoms. American Phytopathological Society Annual Meeting.

Interpretive Summary:

Technical Abstract: Absence of a reliable reverse genetics system for Tomato spotted wilt virus (TSWV) has impeded direct demonstration of gene function. We previously used a Tobacco mosaic virus (TMV)-based expression system to demonstrate that the TSWV NSm protein is able to support cell-to-cell movement in the absence of any other TSWV proteins. The TMV-based expression system also facilitated demonstration that NSm induced tubule formation in protoplasts, supported long-distance movement and induced TSWV-like symptoms in plants. We have now identified the essential NSm domains required for tubule formation, movement and symptoms using deletion-mapping and alanine-substitution mutagenesis via the TMV-based system. Two regions of NSm were required for both tubule formation in protoplasts and cell-to-cell movement in plants, indicating a correlation between these activities. Results of our mutagenesis studies of conserved amino acids suggest that the function(s) predicted from domains common to tospovirus NSm proteins may be conserved across the genus. Further exploration of functions of this interesting protein from both additional TSWV isolates and other tospovirus species is merited.