Emilio Stefani

Bio: Emilio Stefani is an academic researcher from University of Modena and Reggio Emilia. The author has contributed to research in topics: Medicine & PEST analysis. The author has an hindex of 16, co-authored 66 publications receiving 890 citations. Previous affiliations of Emilio Stefani include University of Göttingen & University of Bologna.

Plant Growth Promoting and Biocontrol Activity of Streptomyces spp. as Endophytes.

Abstract: There has been many recent studies on the use of microbial antagonists to control diseases incited by soilborne and airborne plant pathogenic bacteria and fungi, in an attempt to replace existing methods of chemical control and avoid extensive use of fungicides, which often lead to resistance in plant pathogens. In agriculture, plant growth-promoting and biocontrol microorganisms have emerged as safe alternatives to chemical pesticides. Streptomyces spp. and their metabolites may have great potential as excellent agents for controlling various fungal and bacterial phytopathogens. Streptomycetes belong to the rhizosoil microbial communities and are efficient colonizers of plant tissues, from roots to the aerial parts. They are active producers of antibiotics and volatile organic compounds, both in soil and in planta, and this feature is helpful for identifying active antagonists of plant pathogens and can be used in several cropping systems as biocontrol agents. Additionally, their ability to promote plant growth has been demonstrated in a number of crops, thus inspiring the wide application of streptomycetes as biofertilizers to increase plant productivity. The present review highlights Streptomyces spp.-mediated functional traits, such as enhancement of plant growth and biocontrol of phytopathogens.

Detection of Pseudomonas syringae pv. actinidiae in kiwifruit pollen samples.

Abstract: Presence of Pseudomonas syringae pv. actinidiae (Psa), the causal agent of bacterial canker of kiwifruit, in pollen samples collected from infected and non infected orchards in Italy and in New Zealand was determined by polymerase chain reaction (PCR) and by direct bacterial isolation. Psa was isolated only from pollen samples collected in Italy, including pollen collected from two uninfected orchards, which the following year showed signs of infection. Psa was also detected in pollen collected from male and female vines in an Italian infected orchard. Pollen samples from Italy, but not from New Zealand, were collected with a vacuum device. Psa could not be isolated from any of the 25 New Zealand pollen samples analysed. This is the first report of Psa being associated with pollen. There is currently no evidence that artificial pollination leads to increased infection or that pollen has been responsible for the introduction of Psa in a previously Psa-free area.

Revised Classification Scheme of Phytoplasmas based on RFLP Analyses of 16S rRNA and Ribosomal Protein Gene Sequences

Abstract: RFLP analyses of 16S rDNA nested PCR products from 34 phytoplasma strains with 17 restriction enzymes delineated distinct pattern types. Based on similarity coefficients derived from RFLP analyses, the 34 representative phytoplasma strains were differentiated into 14 major groups (termed 16Sr groups) and 32 sub-groups. The similarity coefficients of RFLP patterns between distinct groups were 90% or below. By including additional groups and sub-groups from which RFLP analyses were not performed but for which 16S rDNA sequence data were available to predict restriction sites, a total of 14 groups and 41 sub-groups were proposed. By combined RFLP analyses of 16S rRNA and ribosomal protein gene sequences, thus far, a total of 46 subgroups have been recognized. The phytoplasma 16Sr groups were consistent with the phylogenetic groups (subclades) defined by phylogenetic analysis of near-full-length 16S rRNA gene sequences, indicating that the RFLP-based groups are phylogenetically valid. The approach using RFLP analyses of PCR-amplified 16S rDNA (and ribosomal protein gene sequences) provides a simple, reliable and rapid means for differentiation and classification of unknown phytoplasmas.

Phytoplasma: phytopathogenic mollicutes.

Abstract: ▪ Abstract During the past decade, research has yielded new knowledge about the plant and insect host ranges, geographical distribution, and phylogenetic relationships of phytoplasmas, and a taxonomic system has emerged in which distinct phytoplasmas are named as separate “Candidatus phytoplasma species.” In large part, this progress has resulted from the development and use of molecular methods to detect, identify, and classify phytoplasmas. While these advances continue, research has recently begun on the phytoplasma genome, how phytoplasmas cause disease, the role of mixed phytoplasmal infections in plant diseases, and molecular/genetic phenomena that underlie symptom development in plants. These and other recent advances are laying the foundation for future progress in understanding the mechanisms of phytoplasma pathogenicity, organization of the phytoplasma genome, evolution of new phytoplasma strains and emergence of new diseases, bases of insect transmissibility and specificity of transmission, and...

Detection of Ralstonia solanacearum Strains with a Quantitative, Multiplex, Real-Time, Fluorogenic PCR (TaqMan) Assay

Abstract: A fluorogenic (TaqMan) PCR assay was developed to detect Ralstonia solanacearum strains. Two fluorogenic probes were utilized in a multiplex reaction; one broad-range probe (RS) detected all biovars of R. solanacearum, and a second more specific probe (B2) detected only biovar 2A. Amplification of the target was measured by the 5' nuclease activity of Taq DNA polymerase on each probe, resulting in emission of fluorescence. TaqMan PCR was performed with DNA extracted from 42 R. solanacearum and genetically or serologically related strains to demonstrate the specificity of the assay. In pure cultures, detection of R. solanacearum to >/=10(2) cells ml(-1) was achieved. Sensitivity decreased when TaqMan PCR was performed with inoculated potato tissue extracts, prepared by currently recommended extraction procedures. A third fluorogenic probe (COX), designed with the potato cytochrome oxidase gene sequence, was also developed for use as an internal PCR control and was shown to detect potato DNA in an RS-COX multiplex TaqMan PCR with infected potato tissue. The specificity and sensitivity of the assay, combined with high speed, robustness, reliability, and the possibility of automating the technique, offer potential advantages in routine indexing of potato tubers and other plant material for the presence of R. solanacearum.