Aetiology: The earliest recorded plant virus disease.

Abstract

Pathogenic DNA paints summer foliage gold, and inspired a poet over a millennium ago. The Man'yoshu, meaning 'collection of ten thousand leaves', is the largest and earliest anthology of Japanese poetry — it contains over 4,500 poems written between the early seventh century and the middle of the eighth century, and provides a glimpse of Japanese life during that period. One poem, attributed to the Empress Koken and written in the summer of 752 ad (Fig. 1), describes the autumnal appearance of eupatorium plants in summer1 and is reputedly the earliest written record of the symptoms of a plant virus disease2. Here we show that a geminivirus and an accompanying satellite component isolated from affected eupatorium plants are together responsible for the spectacular foliar display that was first noted by the Empress more than a millennium ago.