RNA virus-like particles in pathogenic plant trypanosomatids.

A double-stranded RNA (ds RNA) with an approximate size of 4.7 kb was found in 6 Phytomonas isolates specifically associated with plant pathogenicity in coconut trees ("Hartrot" disease) and oil palm ("Marchitez sorpressiva" disease). This ds RNA was not detected in 10 non-pathogenic Phytomonas isolates from different lactiferous plants or in the insect trypanosomatids Crithidia and Herpetomonas. Analysis by electron microscopy of a sucrose gradient fraction containing this ds RNA revealed virus-like particles.