Analysis of the biological and molecular variability of Watermelon mosaic virus isolates from Iran

Abstract

Watermelon mosaic virus (WMV) is one of the most important viruses that causes different symptoms in Cucurbitaceae. WMV is a potyvirus with a worldwide distribution, but occurs most commonly in temperate and Mediterranean regions. Cucurbit species grown in Yazd, Esfahan, West Azerbaijan, Hormozgan, and Kerman provinces were surveyed for the relative incidence of WMV in 2004-2005. A total of 757 symptomatic cucurbit and 31 weed species were collected and assayed for infection with WMV. Of 788 leaf samples from cucurbit and weed plants, 190 samples were positive by double antibody sandwich ELISA (DAS-ELISA) using specific polyclonal antibody. Among the weed species tested only colocynth (Citrullus colocynthis) was found to be infected with WMV. The coat protein (CP) gene from 18 representative isolates was PCR amplified, cloned, sequenced, and compared with the sequences available in GeneBank. Phylogenetic analysis using 778 nucleotide long sequences of the coat protein gene showed that these isolates fell into two; groups I and II. Only one isolates (KER.JI.1) was classified in the group II. This isolate had a wider host range and infected Nicotiana debneyii and Datura metel. None of the other 17 isolates could infect these two species. Members of group I were divided into three subgroups; A, B, and C. The subgroup I(B) appears to be a new subgroup comprising only of the Iranian isolates. Phylogenetic analysis based on 200 nucleotides coding for the N-terminal segment of the CP showed that all Iranian isolates except KER.JI.1 clustered with the previously reported WMV strains. All Iranian isolates had a DAG amino acid triplet which is involved in aphid transmissibility. This is the first report on sequence analysis of the nearly full-length CP cDNA clones of WMV isolates from Iran.

Molecular characterization and field survey of Iranian potato virus X isolates

“…Total RNA was extracted from infected leaves of thirteen Nicotiana glutinosa plants mechanically inoculated with PVX isolates using High Pure Viral Nucleic Acid Kit (Roche Diagnostics GmbH, Germany). First-strand cDNA synthesis was performed using Moloney Murine leukaemia virus (MMLV) reverse transcriptase as described as previously by Sharifi et al [22]. The resulting viral cDNAs were used for consecutive PCR reaction with appropriate primers (based on GenBank sequences; AB056718 and M95516) to amplify 9 overlapping fragments spanning the entire genome of two PVX isolates ( Supplementary Fig.…”

Epidemiología y variabilidad patogénica del virus del mosaico del pepino dulce (Pepino mosaic virus). Nuevas enfermedades asociadas a su presencia (torrao o cribado)

“…The geographic grouping correlated to variation in the CP gene has also been reported for other viruses, such as the WMV Iranian isolates (Sharifi et at., 2008) and the Zucchini yellow mosaic virus (ZYMV) Tunisian isolates (Yakoubi et al, 2008).…”

“…A pesar de no manifestarse ninguna diferenciación en función del año de recolección del aislado, sí se observó un agrupamiento de aislados debido a su origen geográfico en el caso de los procedentes de Gran Canaria, que se englobaban en un subgrupo en las dos subunidades de la CP estudiadas. Este fenómeno de agrupación por procedencia geográfica debido a la variación de la CP ha sido observado en WMV y ZYMV (Sharifi et al, 2008;Yakoubi et al, 2008). En este subgrupo de aislados de Gran Canarias se incluyó también un aislado procedente de S. nigrum recogido en Tenerife en 2007, que comparte junto con algunos de los aislados de este grupo, residuos específicos como A1051 en la subunidad de la CP Vp23, G302 e Y303 en la MP, o incluso el único sitio determinado que presenta presión de selección positiva en la zona Pro-Co del RNA1 (V-I 291).…”

Incidence and characterization of Potato virus V infections in Iran

“…The first strand cDNA was synthesized with Moloney murine leukemia virus (MMLV) reverse transcriptase as described as by Sharifi et al [11]. The resulting cDNA was used as template to assemble a full genome by PCR using pairs of primers with the Fast PCR program (http://www.Biocenter.…”