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In the present study, bacterial endophytes were obtained from weeds of potato fields. Their antagonistic activity was screened against potato storage pathogen, Pectobacterium carotovorum subsp. carotovorum (Pcc) (JX029052), in the maceration assay. An endophytic strain, PC-2B was isolated from Convolvulus arvensis L. as a dominant weed of potato fields. In vivo application of this strain led to 58.8% reduction in tuber decay. This motile strain that can produce amylase was identified as Pantoea sp. using phenotypic features and 16S rRNA sequencing. Following PC-2B treatment, 56.7% Reduction in Disease Incidence (RDI) was obtained in preventative and 52% in curative challenges under semi-practical storage trails. Anti-Pcc bioactive compounds of Pantoea sp. was extracted and identified based on H NMR and FT-IR techniques. Two peptide antibiotics including Pantocin A and B with inhibitory effect against Pcc were characterized. These results might indicate that the tested Pantoea strain could be a promising candidate to protect potato tubers against soft rot disease caused by Pcc. However, large-scale complementary trials have to be conducted to validate these results before any recommendations. [ABSTRACT FROM AUTHOR]

In the current study, the phenotypic and molecular properties of twenty-five strains obtained from cankerous tissues or leaf necrotic lesions of different stone fruits were evaluated in north-east of Iran . All strains studied were identified as Xanthomonas arboricola pv. pruni (Xap) based on phenotypic assays and confirmed by means of specific PCR at species and pathovar levels. All obtained strains were pathogenic under artificial inoculation and exhibited brittle necrotic spots on plum leaves of cultivar Santa Rosa under lab conditions. Then, the pathogenic Xap strains were subjected to molecular assays. In a phylogenetic tree constructed with gyrB sequences, no polymorphism was observed in this gene and Iranian Xap strains were clustered with the reference one in a separate group. The ERIC, BOX and REP primer sets generated reproducible genomic PCR profiles in tested strains and, based on combined data for all primers, a low genetic diversity among Xap strains was revealed. In order to achieve results that are more accurate, application of Xap strains from all geographical regions of Iran will be needed to prove little polymorphism observed in Xap population. The current contribution is the first report of molecular homogeneity of Xap strains that were collected from northeastern Iran. [ABSTRACT FROM AUTHOR]

Summary: During summer of 2015, Eucalyptus camaldulensis plants showing witches’ broom, little leaf and general yellowing of the foliage were observed in west of Fars and Khozestan province of Iran. DNA from samples of 22 symptomatic and two asymptomatic trees was extracted and subjected to molecular analyses. Nested‐PCR test using R16F2n/R16R2 primers confirmed phytoplasma presence in 63% of symptomatic Eucalyptus plants. Sequence analysis along with virtual RFLP of the 16S ribosomal DNA allowed to classify three Eucalyptus witches’ broom strains into the “stolbur” (“Candidatus phytoplasma solani”) 16SrXII‐A subgroup. Comparison of the secA and secY gene sequences with sequences deposited in GenBank confirmed the phytoplasma identity. Real and virtual RFLPs of the amplified secY gene using HaeIII, MseI and RsaI restriction enzymes showed profiles indistinguishable from each other. This is the first study reporting E. camaldulensis as a new host species for “Ca. P. solani.” [ABSTRACT FROM AUTHOR]

In the current study, molecular typing of 50 Erwinia amylovora strains related to different regions in Iran was evaluated using multi-locus sequence analysis and variable number of tandem repeats. In the first assay, phylogenetic tree based on partial sequences of recombinase A, sigma factor S and a heat shock protein GroEL showed significant identity in studied gene sequences. A single nucleotide variation in groEL was determined in IrGh59 strain related to Crataegus spp. from Ghazvin Province. In VNTR analysis, the same fingerprinting profile similar to E. amylovora reference strain ATCC49946 was yielded for tested strains except NBQ1 and MQ1 which may reflect a unique contaminating source for this disease in Iran. In addition, the honey-bee movements with respect to blossom season probably have a considerable role in fire blight unique dispersal in our area. The NBQ1 and MQ1 strains generated different VNTR profiles, isolated from cultivars Neishabour and Esfehan of Cydonia oblonga plant, respectively. No definite assessment can be expressed in this case. However, possible entry of other infection mass from neighboring countries should be determined. Overall, VNTR profile analyses are recommended as a tool to evaluate genetic differences in E. amylovora populations. In addition, employing more strains from different known sources could be assistance to achieve more accurate results about E. amylovora genetic variation and also fire blight distribution patterns. [ABSTRACT FROM AUTHOR]

Enhancement of plant growth by Bacillus is well documented and several mechanisms have been suggested for the phytostimulatory activity of this group of plant growth-promoting rhizobacteria (PGPR). In the present work, the PGP potential of plant associatedBacillusspp. and their growth-promoting effect on wheat were studied. Six out of 35 strains were chosen based on seed germination assay, plant growth-promoting abilities, enzymatic function, and auxin production. All tested strains were subjected to pot experiments and their phenotypic and molecular assays were also done. Two Bacillus strains including WhIr-15 and WhIr-12 produce maximum amount of auxin (16.2 and 14 µg ml−1, respectively). Strain WhIr-15 had just the ability to produce indo-3-acetic acid (IAA), lipase, and protease enzymes. Strain WhIr-12 was also recorded positive for siderophore, auxin production, and phosphorus (P) solubilization. Bacterial IAA production positively correlated with root length (r = 0.875;p ≤ 0.05). Significant enhancement in root weight (71% and 53%) and in panicle weight (91% and 77%) was recorded in WhIr-15 and WhIr-12, respectively, over untreated controls. Based on phenotypic and 16S rDNA sequencing, these two strains belong toBacillussp. Based on our results, phytohormone-producingBacillussp. can be applied at field level to improve wheat productivity. [ABSTRACT FROM PUBLISHER]

Bacillusspp. were isolated from Iranian tomato fields and evaluated for their efficacy against root-knot nematodes,Meloidogyne javanica. The 52 spore-forming bacterium isolates were obtained from tomato rhizosphere following heat treatment. Eight isolates were chosen based on their potency in prevention ofM. javanicaegg hatch and juvenile mortality and production of proteolytic enzymes in Petri plates. Their ability to form biofilms were also determined in pot experiments. According to phenotypic traits and 16s rDNA sequencing, all selected isolates belonged toBacillusspp. includingB. cereusandB. pumilus. Treatment with bacterial culture filtratesin vitrocaused juvenile mortality of 72 to 99% after 48 h. After four days, the percentage of egg hatch ranged from 1.6 to 59% depending on the isolate.Bacillus pumilus(ToIr-MA) andBacillussp. (ToIr-10) were found to have significant ability to produce extracellular proteases and to form maximum biofilm, considerably reducing the number of egg masses and root gall index (P= 0.05) in comparison to untreated plants. Application of ToIr-MA and ToIr-10 enhanced the fresh and dry weights of shoot and root systems. There was significant enhancement in dry root weight (45 and 50%) and shoot weight (67 and 75%). Results suggest that these twoBacillusspp. have potential as biocontrol agents against root-knot disease in tomato production. [ABSTRACT FROM AUTHOR]

Nanotechnology has begun to play a remarkable role in various fields of science and technology. In biomedical applications, nanoparticles have opened new horizons, especially for biosensing, targeted delivery of therapeutics, and so forth. Among drug delivery systems (DDSs), smart nanocarriers that respond to specific stimuli in their environment represent a growing field. Nanoplatforms that can be activated by an external application of light can be used for a wide variety of photoactivated therapies, especially light-triggered DDSs, relying on photoisomerization, photo-cross-linking/un-cross-linking, photoreduction, and so forth. In addition, light activation has potential in photodynamic therapy, photothermal therapy, radiotherapy, protected delivery of bioactive moieties, anticancer drug delivery systems, and theranostics (i.e., real-time monitoring and tracking combined with a therapeutic action to different diseases sites and organs). Combinations of these approaches can lead to enhanced and synergistic therapies, employing light as a trigger or for activation. Nonlinear light absorption mechanisms such as two-photon absorption and photon upconversion have been employed in the design of light-responsive DDSs. The integration of a light stimulus into dual/multiresponsive nanocarriers can provide spatiotemporal controlled delivery and release of therapeutic agents, targeted and controlled nanosystems, combined delivery of two or more agents, their on-demand release under specific conditions, and so forth. Overall, light-activated nanomedicines and DDSs are expected to provide more effective therapies against serious diseases such as cancers, inflammation, infections, and cardiovascular disease with reduced side effects and will open new doors toward the treatment of patients worldwide.

This study focuses on the potential of Pectobacterium carotovorum subsp. carotovorum (Pcc) strains producing bacteriocin as a tool to control potato soft rot disease. Thirty out of 48 purified bacterial strains were characterized as Pcc using specific PCR and phenotypic tests. The pathogenicity and pectate degrading assays were recorded positive for 13 strains. Bacteriocin typing clustered producers into three groups according to their antimicrobial spectra. Majority of the producers except strains of group II showed antibacterial activity toward relative genus and the role of UV or mitomycin C was inductive. In addition, none of the distant genus was sensitive to Pcc bacteriocins except Rhizobium vitis. Molecular detection of four bacteriocins including carotovoricin, carosin S1, S2 and carosin D was performed. Overall, 54.5% of group I, 47.3 and 70% of groups II and III strains carried carotovoricin and four strains harbored gene corresponding to carosin S1. According to our data divers antimicrobial patterns obtained by Pcc strains and existence of new bateriocines could be possible. Moreover, our findings recommended that direct application of P29 or expression of corresponding genes of Pog22 or P21 in a nonpathogenic strain as a biocontrol agent may improve soft rot disease control., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)