Identification of a Low Molecular Weight Component of Wheat Yellow Mosaic Virus RNA1 in Infected Wheat

Repeated passage of several fungus-transmitted plant viruses can lead to sequence deletion in their hosts. In this paper, Northern blotting analysis revealed that a low molecular weight component of Wheat yellow mosaic virus(WYMV) RNA1 was detected after the twelfth passage of mechanical inoculation in wheat plants associated with exacerbate symptoms displayed and exist stably in the inoculated plants to the 26th passage in the experiment. However these low molecular weight RNAs could not be detected in the particles purified from the same infected samples, suggesting that they could not encapsidated in infected wheat. Sequence analysis showed that a contiguous segment of 2380 nucleotides(nt68 to nt2448) was internally deleted from the WYMV RNA1 and flanked by direct repeats of six nucleotides CGTCTC, which supports the “copy choice” model as the possible mechanism of the generation of this low molecular weight component of WYMV RNA1.