Browsing by Author "Massumi, Hossain"

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    Identification of phytoplasmas associated with cultivated and ornamental plants in Kerman Province, Iran
    (Wiley, 2010) Tazehkand, Susan Asghari; Pour, Akbar Hossein; Heydarnejad, Jahangir; Varsani, Arvind; Massumi, Hossain
    Hossain Kerman Province is a major agricultural centre in south-eastern Iran and an increase in agricultural activities results in an increase in disease. We report phytoplasmal infections in Iran of five plant species; spinach (Spinacia oleracea L.), sunflower (Helianthus annuus L.), canola (Brassica napus L.), cucumber (Cucumis sativus L.) and Aegean wallflower (Erysimum cheiri (L.) Crantz; Family Brassicaceae) using in silico restriction fragment length polymorphism and sequence analysis. Amplicons of approximately 300 bp were amplified using polymerase chain reaction ampli- fication with universal P3 ⁄ P7 primer pair. The ampli- fied products were cloned and sequenced. On the basis of in silico restriction analysis of the amplicon digested with 17 distinct restriction enzymes and 16 ⁄ 23S spacer region sequence, Erysimum and cucumber phyllodies (EPh and CuPh2, respectively) were 100% identical and showed closest similarity with members of the peanut witches-broom group (16SrII). Whereas spinach yellows (SpY) and canola phyllody (CaPh) revealed closest homology with phytoplasmas of the aster yellows group (AY) 16SrI. Mixed infections of the SuWB sample were confirmed in which two different phytoplasmas belonging to 16SrII and 16SrVI groups were found. This is the first report of phytoplasmal infection of Aegean wallflower (EPh) caused by a phytoplasma belonging to the 16SrII group. While spinach phytoplasmas have been isolated in the past; however, our isolate from spinach belonging to the 16SrI group is the first spinach isolate from Iran.
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    Turnip curly top virus, a highly divergent geminivirus infecting turnip in Iran
    (Elsevier, 2010) Briddon, Rob W; Heydarnejad, Jahangir; Khosrowfar, Fakhrosadat; Massumi, Hossain; Martin, Darren P; Varsani, Arvin
    From 2006 onwards turnip crops in Fars province, Iran, have been noted with unusual leaf curling and vein swelling symptoms which are characteristic of the leafhopper-transmitted viruses of the genus Curtovirus (family Geminiviridae). Rolling circle amplification was used to clone viruses from five turnip isolates exhibiting leaf curl symptoms. Analysis of the sequences showed them to have >93% sequence identity and to be distinct from all other geminiviruses previously characterised. Analysis of the sequence of this virus, for which we propose the name Turnip curly top virus (TCTV), showed it to have a genome arrangement in the complementary-sense similar to that of curtoviruses (consisting of four overlapping genes) but only two open reading frames in the virion-sense (the curtoviruses encode three). The complementarysense genes are homologous to those of curtoviruses but show little sequence identity to their curtovirus homologs, with the exception of the product of the C4 open reading frame (ORF) which shows ∼70.6% amino acid sequence identity to the C4 of the North American curtoviruses, Pepper curly top virus and Beet mild curly top virus. For curtoviruses the C4 protein is a symptom determinant, which likely explains the similarity of TCTV symptoms to those of curtoviruses. In the virion-sense the predicted product of the V2 ORF of TCTV shows no significant similarity with any proteins in the databases whereas the product of the V1 ORF (encoding the coat protein [CP] of geminiviruses) shows low levels of sequence identity to the CPs of curtoviruses. These findings show TCTV to be a highly divergent geminivirus with similarities to viruses of the genus curtovirus. The significance of these findings, particularly the taxonomic implications are discussed.