Pseudomonas viridiflava, a Multi Host Plant Pathogen with Significant Genetic Variation at the Molecular Level

The pectinolytic species Pseudomonas viridiflava has a wide host range among plants, causing foliar and stem necrotic lesions and basal stem and root rots. However, little is known about the molecular evolution of this species. In this study we investigated the intraspecies genetic variation of P. viridiflava amongst local (Cretan), as well as international isolates of the pathogen. The genetic and phenotypic variability were investigated by molecular fingerprinting (rep-PCR) and partial sequencing of three housekeeping genes (gyrB, rpoD and rpoB), and by biochemical and pathogenicity profiling. The biochemical tests and pathogenicity profiling did not reveal any variability among the isolates studied. However, the molecular fingerprinting patterns and housekeeping gene sequences clearly differentiated them. In a broader phylogenetic comparison of housekeeping gene sequences deposited in GenBank, significant genetic variability at the molecular level was found between isolates of P. viridiflava originated from different host species as well as among isolates from the same host. Our results provide a basis for more comprehensive understanding of the biology, sources and shifts in genetic diversity and evolution of P. viridiflava populations and should support the development of molecular identification tools and epidemiological studies in diseases caused by this species

Stock markets and effective exchange rates in European countries: threshold cointegration findings

© 2015, Eurasia Business and Economics Society. The nexus between stock markets and exchange rates is examined in the case of eight European countries. The sample consists of four economies with national currencies and four that have adopted the euro. Thus, if differences between the two groups in the relationship governing the two markets exist, they will be unveiled. To this effect, a threshold cointegration methodology is adopted that allows for more reliable inferences to be drawn for both the short and long run nexus between the two markets. Monthly data is used covering the period 01/2000–12/2014. The findings reported herein offer support in favor of the portfolio approach thesis over the recent economic crisis period, but this finding is not the case for the entire sample. Bidirectional causality is found for Norway and the UK, pointing to a currency effect on stock markets. In view of the findings reported herein, policies aiming at reducing uncertainty in the stock markets can exert beneficial effects on currency markets

Co-Inoculation with Rhizobia and AMF Inhibited Soybean Red Crown Rot: From Field Study to Plant Defense-Related Gene Expression Analysis

Background: Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. Principal Findings: We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P) additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF) could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for coinoculation with rhizobia and AMF at low P. The root colony forming unit (CFU) decreased over 50 % when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR) genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF. Conclusions: Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined wit

Preconditioning-induced ischemic tolerance: a window into endogenous gearing for cerebroprotection

Ischemic tolerance defines transient resistance to lethal ischemia gained by a prior sublethal noxious stimulus (i.e., preconditioning). This adaptive response is thought to be an evolutionarily conserved defense mechanism, observed in a wide variety of species. Preconditioning confers ischemic tolerance if not in all, in most organ systems, including the heart, kidney, liver, and small intestine. Since the first landmark experimental demonstration of ischemic tolerance in the gerbil brain in early 1990's, basic scientific knowledge on the mechanisms of cerebral ischemic tolerance increased substantially. Various noxious stimuli can precondition the brain, presumably through a common mechanism, genomic reprogramming. Ischemic tolerance occurs in two temporally distinct windows. Early tolerance can be achieved within minutes, but wanes also rapidly, within hours. Delayed tolerance develops in hours and lasts for days. The main mechanism involved in early tolerance is adaptation of membrane receptors, whereas gene activation with subsequent de novo protein synthesis dominates delayed tolerance. Ischemic preconditioning is associated with robust cerebroprotection in animals. In humans, transient ischemic attacks may be the clinical correlate of preconditioning leading to ischemic tolerance. Mimicking the mechanisms of this unique endogenous protection process is therefore a potential strategy for stroke prevention. Perhaps new remedies for stroke are very close, right in our cells

Phenotypic and genotypic characterization of pseudomonas savastanoi pv. savastanoi isolates and disease prevalence of olive knot disease in Marmara region of Turkey [Marmara bölgesinde zeytin dal kanseri hastalıgının yaygınlıgı ve pseudomonas savastanoi pv. savastanoi izolatlarının fenotipik ve Genotipik Karakterizasyonu]

Olive growing areas in Tekirdag, Çanakkale, Bali{dotless}kesir, Bursa, and Yalova cities of Marmara region were visited and prevalence and incidence of olive knot disease were noted. Disease prevalence was recorded as 100, 81, 66, 4 and 0% in Çanakkale, Bali{dotless}kesir, Tekirdag, Bursa and Yalova, respectively. Disease incidence was 73, 56, 30 and 0.6% in Çanakkale, Bali{dotless}kesir, Tekirdag and Bursa, respectively. Totaly 208 bacterial strains which showed positive hypersensitive reaction on tobacco leaves were isolated from 104 diseased plants on King's medium B and PVF1 medium from Marmara region. Pathogenicity tests were performed with selected 38 strains and a reference strain (CFPB 1672). All strains were pathogenic on olive plants cv Edremit. Eighty eight strains were re-isolated and used in identification tests. All strains were gram negative, oxidase negative, pectolytic activity negative, levan negative, and arginin dehydrolase negative, but hypersensitive reaction on tobacco leaves was positive. The identification of the strains was confirmed by BIOLOG, spesific-PCR and microbial identification system (MIS) based on whole cell fatty acids. Pseudomonas savastanoi pv. savastanoi strains showed phenotypic similarity as a ratio of 96.7% by whole cell fatty acid compositions. The strains were genotypically similar as a ratio of 97.4% by polymorphism in BOX-PCR. © Ankara Üniversitesi Ziraat Fakültesi

First report of bacterial blight of anthurium caused by Xanthomonas axonopodis pv. dieffenbachiae in Turkey

[No abstract available