Penicillium rhizophilum, a novel species in the section Exilicaulis isolated from the rhizosphere of sugarcane in Southwest Iran.

During a survey of species diversity of Penicillium and Talaromyces in sugarcane (Saccharum officinarum) rhizosphere in the Khuzestan province of Iran [1], 195 strains were examined, from which 187 belonged to Penicillium (11 species) and eight to Talaromyces (one species). In the present study, three strains of Penicillium belonging to section Exilicaulis series Restricta, identified as P. restrictum by Ansari et al. [1], were subjected to a phylogenetic study. The multilocus phylogeny of partial ß-tubulin, calmodulin and RNA polymerase II second largest subunit genes enabled the recognition of one new phylogenetic species that is here formally described as Penicillium rhizophilum sp. nov. This species is phylogenetically distinct in series Restricta, but it does not show significant morphological differences from other species previously classified in the series. Therefore, we here placed bias on the phylogenetic species concept. The holotype of Penicillium rhizophilum sp. nov. is IRAN 18169F and the ex-type culture is LA30T (=IRAN 4042CT=CBS 149737T).

Identification of genes differentially expressed during interaction of Mexican lime tree infected with "Candidatus Phytoplasma aurantifolia".

BACKGROUND: "Candidatus Phytoplasma aurantifolia", is the causative agent of witches' broom disease in Mexican lime trees (Citrus aurantifolia L.), and is responsible for major losses of Mexican lime trees in Southern Iran and Oman. The pathogen is strictly biotrophic, and thus is completely dependent on living host cells for its survival. The molecular basis of compatibility and disease development in this system is poorly understood. Therefore, we have applied a cDNA- amplified fragment length polymorphism (AFLP) approach to analyze gene expression in Mexican lime trees infected by "Ca. Phytoplasma aurantifolia". RESULTS: We carried out cDNA-AFLP analysis on grafted infected Mexican lime trees of the susceptible cultivar at the representative symptoms stage. Selective amplifications with 43 primer combinations allowed the visualisation of 55 transcript-derived fragments that were expressed differentially between infected and non-infected leaves. We sequenced 51 fragments, 36 of which were identified as lime tree transcripts after homology searching. Of the 36 genes, 70.5% were down-regulated during infection and could be classified into various functional groups. We showed that Mexican lime tree genes that were homologous to known resistance genes tended to be repressed in response to infection. These included the genes for modifier of snc1 and autophagy protein 5. Furthermore, down-regulation of genes involved in metabolism, transcription, transport and cytoskeleton was observed, which included the genes for formin, importin ß 3, transducin, L-asparaginase, glycerophosphoryl diester phosphodiesterase, and RNA polymerase ß. In contrast, genes that encoded a proline-rich protein, ubiquitin-protein ligase, phosphatidyl glycerol specific phospholipase C-like, and serine/threonine-protein kinase were up-regulated during the infection. CONCLUSION: The present study identifies a number of candidate genes that might be involved in the interaction of Mexican lime trees with "Candidatus Phytoplasma aurantifolia". These results should help to elucidate the molecular basis of the infection process and to identify genes that could be targeted to increase plant resistance and inhibit the growth and reproduction of the pathogen.

Pathogenicity of Pochonia species on eggs of Meloidogyne javanica.

Among fungi, species of the genus Pochonia Batista & O.M. Fonseca are considered as promising biological control agents with high potential to reduce root-knot nematode (RKN) and nematode populations. In this research we investigated Fars province of Iran for the presence of Pochonia spp., compared pathogenicity of different Pochonia species on eggs of RKN in vitro, and selected the best isolates for further studies. During 2004-2006, 128 soil samples of fields infested with cyst nematodes and 18 soil samples infested with RKN were collected from Fars province of Iran. In vitro pathogenicity tests were carried out on 36 isolates of Pochonia spp. obtained from CBS and IRAN culture collections. The seven best isolates of this experiment were selected for greenhouse test and their ability in controlling RKN was examined in natural soil. In greenhouse test fresh weight of plant's tops and roots, gall index, nematode multiplication, second-stage juveniles' population in soil, reproduction rate (P(f)/P(i)), proportion of infected eggs, control efficacy, root colonization and soil colony forming units were determined. In vitro pathogenicity of Pochonia on RKN eggs varied between 39% and 95% eggs infected. In greenhouse experiment, three isolates are promising for control of RKN and selected isolates are subjected to more extensive testing to determine their effectiveness in a range of conditions before being developed as commercial biological control agents.

Generation and molecular docking analysis of specific single-chain variable fragments selected by phage display against the recombinant nucleocapsid protein of fig mosaic virus.

The mosaic disease caused by fig mosaic virus (FMV) is considered the plague of fig worldwide. A naïve phage display library, raised against the recombinant nucleocapsid protein of FMV (FMV-Np) was screened to obtain specific monoclonal recombinant antibodies in the form of single chain variable fragments (scFvs). After three rounds of biopanning, the bacterially expressed FMV-Np was used as an antigen for selecting specific phages for the production of specific soluble scFvs to be used in immunological assays. The binding specificity of scFvs against FMV-infected fig samples was evaluated by immunoblotting and Plate trapped antigen-ELISA (PTA-ELISA), which revealed efficient of the resultant scFvs to the target antigen. Silico homology-modelling and molecular docking analysis confirmed the scFv and FMV-Np interactions with the anti-FMV-Np scFv through an estimated binding energy of -650 kj mol-1; considered to be generated from the interactions between 13 amino acids residues predicted as putative epitopes in the interface pocket of FMV-Np and scFv antibody. This high affinity was further confirmed in the specificity of ELISA and immunoblotting assays. This is the first report on the application of phage display technology to generate specific recombinant scFvs against FMV that can be applied in development of antibody-mediated protection strategy to control the fig mosaic disease.

Production of a polyclonal antiserum against recombinant nucleocapsid protein and its application for the detection of fig mosaic virus.

Mosaic disease (MD), caused by Fig mosaic emaravirus (FMV), is the most important and devastating virus disease of fig trees worldwide. The detection of FMV in infected plants is possible only through the use of molecular techniques, i.e. RT-PCR and LAMP, which both offer high sensitivity of detection, but are also considered laborious when dealing with a large number of samples. To cope with this restriction, a polyclonal antiserum through the immunization of a rabbit by injecting the recombinant nucleocapsid protein (NP) of FMV was raised and evaluated for its efficacy in Western Blot, Dot immuno-binding and DAS-ELISA. The results obtained showed that the raised antiserum was able to identify the nucleocapsid protein of FMV (p3) which was found to have an estimated molecular weight of ca. 35 KDa. In addition, the antiserum, when used in the three serological assays, was able to detect the p3 of FMV in protein extracts of infected plants with different levels of efficacy. Dot immuno-binding, using denatured plant protein extract, proved to be the most efficient serological assay for detecting FMV in samples collected from different fig orchards. This is the first report on an antiserum raised against FMV that could be used for immunological detection of the virus.

Fusarium ershadii sp. nov., a Pathogen on Asparagus officinalis and Musa acuminata.

Two Fusarium strains, isolated from Asparagus in Italy and Musa in Vietnam respectively, proved to be members of an undescribed clade within the Fusarium solani species complex based on phylogenetic species recognition on ITS, partial RPB2 and EF-1α gene fragments. Macro- and micro-morphological investigations followed with physiological studies done on this new species: Fusarium ershadii sp. nov can be distinguished by its conidial morphology. Both isolates of Fusarium ershadii were shown to be pathogenic to the monocot Asparagus officinalis when inoculated on roots and induced hollow root symptoms within two weeks in Asparagus officinalis seedlings. In comparison mild disease symptoms were observed by the same strains on Musa acuminata seedlings.

Prevalence of Tobacco mosaic virus in Iran and Evolutionary Analyses of the Coat Protein Gene.

The incidence and distribution of Tobacco mosaic virus (TMV) and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP) gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100%) among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each sub-group was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

A synthetic garden of state of the art natural protein nanoarchitectures dispersed in nanofluids.

As a significant discovery in the 20th century, carbon nanotubes are attracting particular attention in many unique fields such as electronics, catalysts, hydrogen storage composites, gas sensors, drug delivery, medical diagnostics, therapeutics and nanofluids. In this project, we focus on self-assembled synthetic special natural protein alpha-lactalbumin nanotubes with different (straight, waved, coiled, regularly bent, branched, beaded) shapes, nanospherical particles, nanorods, nanowires, nanopores, polyhedral (hexagonal network, spherical, cubic) nanostructures, nanochannels, nanofibers, nanosheets, nanoleaves, nanowave branched structures, nanobeads, nanoflowers, nanocapsules, novel nano-hybrids consisting of tubes and rods (new core-shell), nanocrystal shapes, apiary or cobweb, branched nanotubes with Y-junctions, nano membrane structures, nano sweep symmetrical shape, nano sponge structures, nano helical homogeneous structures and nano perpendicular and horizontal stable hollow single-walled natural protein nanotubes (NPNTs). These were successfully synthesized by the chemical hydrolysis sol--gel method and partial biochemical enzymatic hydrolysis by cleavage sites (Asp-X and Glu-X) of the milk protein a-lactalbumin by using various organic surfactants, pH controller functions and divalent metallic salt ions as a binding site or ions ligand formation between two bio-based building blocks to form remarkable various new morphologies in appearance of nanoemulsions and clear green nanofluids, for application in the diet nutrition food science and pharmaceutical industry. The characterization by SEM, TEM, XRD and Raman spectroscopy (specific D and G bond in protein nanotubes) confirmed the novelty of these products.