Impact of two different dehydration methods on saffron quality, concerning the prevalence of Saffron latent virus (SaLV) in Iran.

The dehydration process is a prerequisite to preserve saffron for a long time. According to this process, saffron shows differences in the main compounds responsible for its quality (colour, taste, aroma, and flavonol content). At present, the freeze-drying method obtains dried products with the highest quality. Viruses can modify the physiology and metabolism of plants, being able to affect the activities of several enzymes. For this reason, the main compounds of saffron have been analyzed under two different dehydrating processes, freeze-drying and dark-drying, considering their infection status with the Saffron latent virus (SaLV). Results showed that the picrocrocin and safranal content enables to differ dark-dried samples from freeze-dried ones. Besides, the kaempferol-3-O-sophoroside-7-O-glucoside content allows differentiating between SaLV-infected (SaLV+) and uninfected (SaLV-) saffron samples. Moreover, our data suggest that the freeze-drying would decrease crocins content, and dark-drying can nullify the adverse effect of SaLV on crocins content.

The effects of geographical origin and virus infection on the saffron (Crocus sativus L.) quality.

Saffron is appreciated by its colour, taste, and aroma. To examine the effect of abiotic and biotic stress on these main properties, in the span of 2014-2016, saffron stigmas were collected from major different saffron cultivation areas of Iran and saffron quality was estimated. The quality of saffron was assessed by ultraviolet-visible spectroscopy following the ISO3632:2011 standard. However, the composition and concentration of crocetin esters, picrocrocin, safranal, and kaempferols, the most critical compounds determining the properties and quality of saffron can vary with the geographical origin and virus effects, being more accurate High-Performance Liquid Chromatography and Diode Array Detection (HPLC-DAD) methods were used to analyze saffron quality. Using HPLC-DAD we analyzed saffron plants grown at various conditions (considering altitude, temperature, and precipitation/rainfall) and in presence/absence of virus infections; we found that edaphoclimatic and cultivation conditions significantly determine the quality of the spice and the presence of virus modifies the content of its metabolites.

Molecular Characterization of a Novel Putative Partitivirus Infecting Cytospora sacchari, a Plant Pathogenic Fungus.

Three double-stranded RNAs (dsRNAs), approximately 1.85, 1.65 and 1.27 kb in size, were detected in an isolate of Cytospora sacchari from Iran. Partial nucleotide sequence revealed a 1,284 bp segment containing one ORF that potentially encodes a 405 aa protein. This protein contains conserved motifs related to RNA dependent RNA polymerases (RdRp) that showed similarity to RdRps of partitiviruses. The results indicate that these dsRNAs represent a novel Partitivirus that we tentatively designate Cytospora sacchari partitivirus (CsPV). Treatment of the fungal strain by cyclohexamide and also hyphal tip culture had no effect on removing the putative virus. Phylogenetic analysis of putative RdRp of CsPV and other partitiviruses places CsPV as a member of the genus Partitivirus in the family Partitiviridae, and clustering with Aspergillus ochraceous virus 1.

Analysis of Soybean mosaic virus genetic diversity in Iran allows the characterization of a new mutation resulting in overcoming Rsv4-resistance.

The genetic variation and population structure of Soybean mosaic virus (SMV) in Iran was analysed through the characterization of a set of isolates collected in the soybean-growing provinces of Iran. The partial nucleotide sequence of these isolates showed a single, undifferentiated population with low genetic diversity, highly differentiated from other SMV world populations. These traits are compatible with a population bottleneck associated with the recent introduction of SMV in Iran. Phylogenetic analyses suggest that SMV was introduced into Iran from East Asia, with at least three introduction events. The limited genetic diversification of SMV in Iran may be explained by strong negative selection in most viral genes eliminating the majority of mutations, together with recombination purging deleterious mutations. The pathogenicity of Iranian SMV isolates was typified on a set of soybean differential lines either susceptible or carrying different resistance genes or alleles to SMV. Two pathotypes were distinguished according to the ability to overcome Rsv4 resistance in line V94-5152. Amino acid sequence comparisons of virulent and avirulent isolates on V94-5152 (Rsv4), plus site-directed mutagenesis in a biologically active cDNA clone, identified mutation S1053N in the P3 protein as the determinant for virulence on V94-5152. Codon 1053 was shown to be under positive selection, and S1053N-determined Rsv4-virulence occurred in isolates with different genealogies. The V94-5152 (Rsv4)-virulence determinant in Iranian isolates maps into a different amino acid position in the P3 protein than those previously reported, indicating different evolutionary pathways towards resistance breaking that might be conditioned by sequence context.