Identification of molecular virus-plant interactions in physcomitrella patens following tomato spotted wilt virus infection

• Applicant: Dr. Jan-Wolfhard Kellmann
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: from 2003 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5415368

Novel methods for the identification of host proteins interacting with viral gene products allow new assumptions concerning basic principles of virus replication or virus spreading through infected organisms. Resultant postulations can be confirmed (or unproved) after generating of, or screening for, host mutants which are defective in steps which possibly facilitate pivotal virus functions. The moss Physcomitrella patens allows both, the analysis of mutant collections as well as, with the aid of homologous recombination, generation of a specified mutant defective in a gene of interest. To study molecular virus-plant interactions utilizing P. patens as a host, we established a system to inoculate gametophores with Tomato spotted wilt virus (TSWV). Following western as well as ELISA analysis of virus-treated gametophores, TSWV encoded structural N and non-structural NSm protein could be detected (HÜHNS ET AL., 2003 PLANT CELL TISSUE & ORGAN CULTURE, IN PRESS), assuming that P. patens supports multiplication of TSWV virions. These results encouraged us to propose further approaches ; i.) substantiation of successful P. patens infection by verifying TSWV viral messenger- and genome-complementary S, M, and L RNA species, ii.) detection of virus particles in moss cells by microscopy, combined with concurrent tests for virion infectivity (employed by re-inoculation of tobacco plants), and iii.) attempts to achieve P.patens mutants assumed to be defective in specified molecular TSWV - host interactions.

• DFG Programme: Research Grants