Differential molecular response of maize and Johnson grass against maize dwarf mosaic virus and bermuda grass southern mosaic virus.

Maize dwarf mosaic virus (MDMV) and bermuda grass southern mosaic virus (BgSMV) is the most important cereal potyvirus in Iran. Expression of some key genes in maize plants susceptible and tolerant to MDMV or BgSMV and gene expression profile of MDMV and BgSMV compatible or incompatible to Johnson grass plants were studied. Time points of 1, 9, 24 and 72 h after inoculation with both viruses were investigated as well. By analyzing the expression of the genes, it was identified that in maize infected by MDMV and BgSMV, the transcript levels of the peroxiredoxin, GLP, SAM, NPR1 and chlorophyll a-b binding genes were significantly higher in the tolerant than in susceptible plants during the entire experiment. In the BgSMV inoculated Johnson grass plants, some of the genes related to plant defense responses including NPR1, peroxiredoxin and SAM had higher expression level than the Johnson grass plants inoculated by MDMV. Important genes in maize tolerance like NPR1 and MT-LP, were analyzed by trilinear decomposition analysis and genes clustering. The upregulated expression of genes at one-hour post inoculation showed that the plant response to viruses was activated at the early stage of infection. Keywords: MDMV; BgSMV; gene expression; quantitative real-time PCR; trilinear decomposition analysis.

First report of cucumber mosaic virus subgroups i and ii on soybean, pea, and eggplant in iran.

UNLABELLED: Cucumber mosaic virus (CMV) has the widest host range (> 1000 plant species) of any known plant virus, a large number of vector species, and a wide geographical distribution. A survey was conducted to determine the incidence of CMV of subgroups I and II on selected host crops in northern Iran. A total of 935 leaf samples from 10 host crops (tomato, pea, tobacco, soybean, watermelon, broad bean, squash, cucumber, eggplant, and lettuce) showing virus disease-like symptoms were collected in 12 cities of Golestan and Mazandaran provinces (northern Iran) during 2009 and 2010. Among the field samples tested by double-antibody sandwich ELISA (DAS-ELISA), 275 samples were found to be infected by CMV. These were subsequently evaluated by compound ELISA with monoclonal antibodies. We found that 198 samples were infected by subgroup I, 98 samples by subgroup II and 45 samples by both virus subgroups. Twenty-four samples showed no reaction in compound ELISA. In presented paper, CMV subgroups I and II (CMV-I and CMV-II) have been reported for the first time on soybean, pea and eggplant in Iran, with subgroup I being dominant in the north of the country. KEYWORDS: CMV; subgroups I and II; compound ELISA; monoclonal antibody.