Title: Rose rosette and Redbud yellow ringspot are caused by two new emaraviruses

Authors: Laney, AG : Gergerich, R : Keller, K : Martin, R : Tzanetakis, I

Published in: Phytopathology [Phytopathology]. Vol. 100, no. 6, suppl. 1, page S67. Jun 2010.

Abstract: Rose rosette (RR) was first described in Canada in the 1940s and Redbud yellow ringspot (RYRS) in Arkansas in the 1970s. Since then, the only major breakthroughs on the etiology of RR or RYRS was the discovery of double membrane-bound bodies in symptomatic plants of both diseases and evidence that the RR agent is transmitted by eriophyid mites. RR, a widespread disease east of the Mississippi River and a major threat to the ornamental industry, is usually associated with witches' broom, lateral shoot elongation, and malformation of flowers and leaves, culminating in plant death. RYRS, a disease with unknown geographic distribution, causes chlorotic ringspots, oak-leaf, and vein chlorosis in mature leaves. We have acquired data suggesting that two new negative-stranded RNA viruses, members of the newly established genus Emaravirus, and provisionally named Rose rosette-associated virus (RRaV) and Redbud yellow ringspot-associated virus (RYRSaV), are associated with RR and RYRS respectively. Detection protocols have been developed and used to survey symptomatic roses and redbuds for the respective viruses. Both viruses were found in almost all diseased samples. Potential field alternative hosts were surveyed and several herbaceous hosts were inoculated mechanically and by grafting. Transmission studies for RYRSaV using an Aceria species eriophyid mite are under way."

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And similar paper:

Title: Redbud yellow ringspot disease: Thirty years of research

Authors: Laney, AG : Gergerich, RC : Tzanetakis, IE

Phytopathology [Phytopathology]. Vol. 100, no. 6, suppl. 1, page S201. Jun 2010.

Abstract: In the 1970s a disease was found infecting eastern redbud, Cercis canadensis. Symptoms include chlorotic ringspots, oak-leaf, and vein chlorosis in mature leaves and are usually expressed early in the season. Previous work revealed the presence of virus-like double membrane-bound bodies in diseased plants. Similar bodies have been found associated with several diseases including rose rosette, high plains disease, fig mosaic, European mountain ash ringspot, and thistle mosaic. Recently, the genomes of the viruses associated with Fig mosaic (FMV) and European mountain ash ringspot (EMARaV) were sequenced, and found to be negative sense ssRNA viruses related to tospoviruses. We have obtained sequence information of a virus found in yellow ringspot diseased plants, provisionally named Redbud yellow ringspot-associated virus (RYRaV). Detection protocols have been developed and used in a survey of symptomatic redbud trees. RYRaV was found closely associated with diseased trees as more than 90% of tested material was infected with the virus. Potential field alternative hosts were surveyed and a several herbaceous hosts were inoculated mechanically and by grafting. Transmission studies using eriophyid mites are under way."