Publication no. P-1998-0922-03R

Virology

Nucleotide Sequence and RT-PCR Detection of a Virus Associated with Grapevine Rupestris Stem-Pitting Disease. Yun-Ping Zhang, Jerry K. Uyemoto, Deborah A. Golino, and Adib Rowhani. Department of Plant Pathology, One Shields Avenue, University of California, Davis 95616. Phytopathology 88:1231-1237. Accepted for publication 7 August 1998. Copyright 1998 The American Phytopathological Society.

Grapevine rupestris stem pitting (RSP) is a graft-transmissible disease of unknown etiology. We have characterized a virus associated with this disease. The entire genomic sequence (GenBank accession number AF026278) consisted of 8,725 nucleotides excluding a poly(A) tail. Six open reading frames (ORF) were found. ORF1 potentially encodes a polypeptide with a methyltransferase domain, a papain-like proteinase domain, a helicase domain, and a RNA-dependent RNA polymerase domain; ORF2, ORF3, and ORF4 compose a triple-gene block; ORF5 encodes a coat protein; and ORF6 is located near the 3(prime) end with unknown function. Sequence analysis indicated that the virus is most similar to apple stem-pitting virus and may be allied with the carla- and potexviruses and grouped with other viruses that infect woody hosts. A specific reverse-transcription polymerase chain reaction (RT-PCR)-based detection method was developed. Among 62 grapevine sources known to be infected with rupestris stem-pitting disease, 60 sources tested positive by RT-PCR. Among 43 healthy vines tested, all were negative. The name grapevine rupestris stem-pitting-associated virus is proposed.