The first plant virus

The Man'yoshu (meaning "collection of ten thousand leaves") is the oldest anthology of poetry in Japan. One poem, written by the Empress Koken in 752 AD, describes the unusual autumnal appearance of eupatorium plants during the summer — they exhibit a characteristic yellow leaf pattern on their leaves, attributed to the presence of a geminivirus called eupatorium yellow-vein virus (EpYVV). In a Brief Communication in the April 24 Nature, Keith Saunders and colleagues at The John Innes Centre, Norwich, UK, show that a geminivirus and accompanying satellite component are responsible for the foliar patterns of eupatorium plants. This finding suggests that the poem also represents the first known record of a plant virus (Nature, 422:831, April 24, 2003).

Saunders et al. investigated the possibility that, in addition to EpYVV, a DNA β-satellite component was required for the aetiology of eupatorium plants. Cloned tandem repeats...