Identification and coat protein nucleotide sequence of turnip mosaic potyvirus from eruca sativa in Saudi Arabia

Abstract

The goal behind this study was the identification, biological and molecular characterization of a virus infecting garden rocket (Eruca sativa Mill) and producing severe symptoms on it in Riyadh region, Saudi Arabia. Mosaic, stunting and deformation were observed on field grown garden rocket plants. Mechanical inoculation of twelve plant species with sap prepared from infected garden rocket plants resulted in infection of four of them. These were E. sativa Mill, Raphanus sativus L., Brassica rapa L. and Chenopodium ammaranticolor Cost and Reyn L. Symptoms on the first three plant species were systemic mosaic, stunting and deformation, whereas symptoms on C. ammaranticolor were local lesions. Brevicoryne brassicae L., transmitted the virus to E. sativa in a non-persistent manner. Electronmicroscopic examination of carbon-coated grids prepared by the leaf dip method revealed flexuous virus particles typical of potyviruses. Enzyme linked immunosorbent assay indicated that samples collected from symptomatic E. sativa plants in both Riyadh and Qassim regions were infected with turnip mosaic potyvirus (TuMV). Positive results were also obtained using a Reverse Transcription-Polymerase Chain Reaction (RT-PCR) method to detect and identify TuMV from nucleic acid extracts of the symptomatic garden rocket plants collected from that area, using a specific oligonucleotide primer for detection of TuMV-CP. Nucleic Acid Spot Hybridization Assay (NASH) using DIG labeled cDNA probe showed high levels of hybridization signal, whereas no hybridization was observed with uninfected tissues. The nucleotide sequence of the CP gene of the Saudi Arabian isolate of TuMV detected in garden rocket and tentatively denoted (TuMV-SA-Ro) was determined to be composed of 862 nucleotides in length. © 2010 Academic Journals Inc.