Alfalfa Mosaic Virus RNAs Serve as Cap Donors for Tomato Spotted Wilt Virus Transcription during Coinfection of Nicotiana benthamiana

Tomato spotted wilt virus (TSWV) was shown to use alfalfa mosaic virus (AMV) RNAs as cap donors in vivo during a mixed infection in Nicotiana benthamiana. By use of nested reverse transcription-PCR, TSWV N and NSs mRNAs provided with capped leader sequences derived from all four AMV RNAs could be cloned and sequenced. The sequence specificity of the putative TSWV endonuclease involved is discussed.