Detection of 'Candidatus Phytoplasma brasiliense' in a new geographic region and existence of two genetically distinct dnaK genotypes

In September 2007, a peach tree (Prunus persica) displaying yellowing symptoms indicative of phytoplasma infection was sampled in Quba region of Azerbaijan. A phytoplasma was detected in the diseased peach tree by nested PCR amplification of its 16Sr DNA with universal primers for phytoplasmas. Phylogenetic analyses of the amplified 16S rDNA showed that the phytoplasma infecting peach tree corresponded to 'Candidatus Phytoplasma brasiliense', a phytoplasma not previously reported in the Euro-Mediterranean area. To set up a detection assay, cloning of a 'Ca. P. brasiliense' DNA fragment was undertaken by comparative RAPD. The amplified dnaK-dnaJ genetic locus was used to design a nested PCR assay able to amplify all 'Ca. P. brasiliense' strains of the subgroup 16SrXV-A without amplifying the related members of the group 16SrII. The use of this assay also confirmed detection for the first time of 'Ca. P. brasiliense' in diseased basil collected in south Lebanon

Integration of Software Agent Technologies and Web Services

Web Services technology enables the automation of service discovery, invocation, and composition. On the other hand, Software Agents provide a distinctive capability in mediating user goals to determine service invocations. Software Agents are autonomous entities that can discover, invoke, compose, and monitor services without user’s intervention. Moreover, agents possess the ability to handle the dynamism of the Web Services environments. Web Services and agent technologies have different problems that limit their functionality when applied separately. The major reason is that agents are not compatible with the widely accepted standards of Web Services. This paper presents a framework that provides an integration of Web Services and Software Agents technologies by making use of a middleware to facilitate their interoperation

First Detection and Characterization of Ca. P. brasiliense From Yellowing Peach Tree in Guba Region of Azerbaijan

<p>"Candidatus Phytoplasma brasiliense", a new phytoplasma taxon associated with hibiscus witches<br>broom disease was firstly described in 2001 in Brazil. The disease was characterized by symptoms of<br>witches' broom, i.e. leaf yellowing and malformation.Yellowing peach tree (Prunus persica) samples<br>reminiscent of phytoplasma infection were collected in September 2007 in Guba region, which is an<br>important fruit and vegetable growing area in Azerbaijan. A phytoplasma was detected in the diseased<br>peach tree by amplification of its 16 S rDNA by nested PCR with universal primers for phytoplasmas.<br>It was furthermore characterized by RFLP and nucleotide sequence analyses of 16S rDNA. It was<br>shown that a phytoplasma infected peach tree is Candidatus Phytoplasma brasiliense. This report con-<br>stitutes the first detection of this phytoplasma in a plant other than hibiscus and elsewhere than in<br>Brazil. To set up a specific detection test, cloning of a 'Ca. P. brasiliense' DNA fragment was underta-<br>ken by comparative RAPD. The amplified dnaK-dnaJ genetic locus was used to design a specific PCR<br>test that amplify all 'Ca. P. brasiliense' isolates of the group 16SrXV-A without amplifying the related<br>members of the group 16SrII.</p&gt

Genetic diversity of "<em>Candidatus</em> Phytoplasma solani" strains associated to ''bois noir" and planthoppers in Azerbaijan

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Important genetic diversity of Candidatus Phytoplasma solani’ related strains associated with bois noir grapevine yellows and planthoppers in Azerbaijan

Bois noir (BN) is an important grapevine yellows endemic to the Euro-Mediterranean basin caused by ‘Candidatus Phytoplasma solani’ (‘Ca. P. solani’), a non culturable plant pathogenic Mollicute. Bois noir symptoms could be associated with ‘Ca. P. solani’ in two Azerbaijanian vineyards where disease incidence and severity were recorded for five local Vitis vinifera cultivars. In order to gain insight into the epidemiology of Bois noir in Azerbaijan, ‘Ca. P. solani’ isolates infecting plants were characterized by multi-locus sequence analysis and their secY and stamp gene sequences compared to that of the strains detected in other plants and in local Cixiidae planthoppers. Genotypes were determined for two non-ribosomal house-keeping genes, namely tuf and secY, as well as two variable markers namely Stamp and mleP1 genes, that respectively encode the antigenic membrane protein AMP and a 2-Hydroxycarboxylate transporter. The Azerbaijanian BN phytoplasma isolates corresponded to three tufB and secY genotypes. A finer differentiation of Azerbaijanian ‘Ca. P. solani’ isolates was obtained with mleP1 as five different mleP1 genetic variants were found. Finally, Stamp gene allowed differentiating four new genotypes in grapevine among the 10 new Stamp genotypes detected in various plants in Azerbaijan. The preliminary survey for infected insects conducted in northern Azerbaijan, led to the identification of Hyalesthes obsoletus and Reptalus noahi as potential vectors for two ‘Ca. P. solani’ new genotypes phylogenetically distant from the known genetic clusters. Altogether these results indicate an important genetic diversity of BN phytoplasmas in Azerbaijan that certainly result from spread through local insect vectors

StAMP encoding the antigenic membrane protein of stolbur phytoplasma is useful for molecular epidemiology

article présenté lors du Second International Phytoplasmologist Working Group meeting (IPWG) ; Neustadt an der Weinstraße (Allemagne) - (2011-09-12 - 2011-09-15) / WorkshopInternational audienc