Using phylogeographic approaches to analyse the dispersal history,velocity and direction of viral lineages — Application to rabies virus spread in Iran

Recent years have seen the extensive use of phylogeographic approaches to unveil the dispersal history of virus epidemics. Spatially explicit reconstructions of viral spread represent valuable sources of lineage movement data that can be exploited to investigate the impact of underlying environmental layers on the dispersal of pathogens. Here, we performed phylogeographic inference and applied different post hoc approaches to analyse a new and comprehensive data set of viral genomes to elucidate the dispersal history and dynamics of rabies virus (RABV) in Iran, which have remained largely unknown. We first analysed the association between environmental factors and variations in dispersal velocity among lineages. Second, we present, test and apply a new approach to study the link between environmental conditions and the dispersal direction of lineages. The statistical performance (power of detection, false‐positive rate) of this new method was assessed using simulations. We performed phylogeographic analyses of RABV genomes, allowing us to describe the large diversity of RABV in Iran and to confirm the cocirculation of several clades in the country. Overall, we estimate a relatively high lineage dispersal velocity, similar to previous estimates for dog rabies virus spread in northern Africa. Finally, we highlight a tendency for RABV lineages to spread in accessible areas associated with high human population density. Our analytical workflow illustrates how phylogeographic approaches can be used to investigate the impact of environmental factors on several aspects of viral dispersal dynamics.     

Physiological Response of Fennel (Foeniculumvulgare Mill.) to Drought Stress and Plant Growth Regulators

Russian Journal of Plant Physiology - Implementing strategies for the efficient use of irrigation water is a priority in areas that encounter water shortage. Fennel (Foeniculum vulgare Mill.) is an...     

The influence of temperature on plant development in a vernalization-requiring winter wheat: A 2-DE based proteomic investigation

In this work, proteomics was used to study the influence of both optimal and low temperatures on growth and development in a vernalization-requiring winter wheat (Triticum aestivum L. cv Cheyenne) after prolonged times of treatment. For this purpose, plants were grown at optimal temperature (20°C) for 14 days (zero point) after which half were transferred to conditioned chambers kept at 4°C for a period of 63 days. Cold tolerance, as estimated from lethal temperatures (LT(50)), and phenological development, as measured by final leaf number (FLN) and shoot apex dissection, were determined. Proteomic analysis indicated a down-accumulation of several photosynthesis-related proteins and a concomitant increase in abundance of some Calvin cycle enzymes. A cold-induced accretion of soluble sugars and proline was observed as well. In parallel, an increase of proteolysis accomplished by an up-modulation of TCA cycle enzymes was also noticed, probably suggesting an efficient recycling of amino acids as energy source. Proteomic analysis of plants grown at optimal temperature allowed to specifically discriminate cold-induced proteins and highlight molecular processes driven by vernalization. Among identified proteins typically involved in vernalization responses and floral transition we observed a marked increase of wrab17, wcor18 and glycine-rich RNA-binding proteins.     

Effect of fungicidal essential oils against Botrytis cinerea and Rhizopus stolonifer rot fungus in vitro conditions

The development of natural crop protection products as alternatives to the use of synthetic fungicides is currently popular. The aim of this study is to evaluate the antifungal effects of several essential oils against the fungal pathogens, Botrytis cinerea and Rhizopus stolonifer, under in vitro condition. Four essential oils (fennel, black caraway, peppermint and thyme) were each tested at five concentrations (0, 200, 400, 600 or 800 μl l^?1). In vitro results showed that the essential oil of black caraway and fennel had the highest fungicidal effect against B. cinerea and R. stolonifer, respectively. The growth of B. cinerea was completely inhibited by the essential oil of black caraway at 400 μl l^?1. Fennel oil perfectly inhibited growth of R. stolonifer fungus colonies at concentration higher than 600 μl L^?1 in potato dextrose agar medium. Percentage of spores germination was the lowest in medium of Fennel and black caraway essential oils, and was the highest in Thyme ones. These results show that plant essential oils can have a strong effect on reducing post-harvest decay. These plant essential oils could provide an alternative to synthetic chemicals to control post-harvest phytopathogenic fungi on fruit.     

Salicylic acid induced changes on antioxidant capacity,pigments and grain yield of soybean genotypes in water deficit condition

Salicylic acid (SA) plays an important role in the regulation of plant growth and development in response to water deficit. The effect of SA (0, 0.4 and 0.8?mM) on some physiological parameters of three soybean genotypes was investigated in three irrigation schedules included (85%, 65% and 45% of field capacity) during 2014–2015. Results showed that water deficit decreased stomatal conductance, leaf area index, relative water content, membrane stability index, yield components and grain yield particularly in L17 genotype. Activities of superoxide dismutase, ascorbate peroxidase and concentration of hydrogen peroxide, proline and total protein were increased in response to water deficit as well as SA applications. SA inhibited catalase activity resulting in increased hydrogen peroxide accumulation in soybean genotypes. Application of 0.4?mM SA decreased the adverse effects of water deficit in soybean genotypes by elevation of antioxidant enzymes activity and reducing malondialdehyde formation especially in Williams genotype.     

Adaptation to chronic length change in explanted airway smooth muscle.

It has been shown that airway smooth muscle in vitro is able to maintain active force over a large length range by adaptation in the absence of periodic stimulations at 4 degrees C (Wang L, Paré PD, and Seow CY. J Appl Physiol 90: 734-740, 2001). In this study, we show that such adaptation also takes place at body temperature and that long-term adaptation results in irreversible functional change in the muscle that could lead to airway hyperresponsiveness. Rabbit tracheal muscle explants were passively maintained at shortened and in situ length for 3 and 7-8 days in culture media; the length-tension relationship was then examined. The length associated with maximal force generation decreased by 10.5 +/- 3.8% (SE) after 3 days and 37.7 +/- 8.5% after 7 or 8 days of passive shortening. At day 3, the left shift in the length-tension curve due to adaptation at short lengths was reversible by readapting the muscle at a longer length. The shift was, however, not completely reversible after 7 days. The results suggest that long-term adaptation of airway smooth muscle could lead to increased muscle stiffness and force-generating ability at short lengths. Under in vivo condition, this could translate into resistance to stretch-induced relaxation and excessive airway narrowing.     

Scolicidal Effects of Black Cumin Seed (Nigella sativa) Essential Oil on Hydatid Cysts

Surgery remains the preferred treatment for hydatid cyst (cystic echinococcosis, CE). Various scolicidal agents have been used for inactivation of protoscolices during surgery, but most of them are associated with adverse side effects. The present study aimed to evaluate the in vitro scolicidal effect of Nigella sativa (Ranunculaceae) essential oil and also its active principle, thymoquinone, against protoscolices of hydatid cysts. Protoscolices were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations of the essential oil (0.01-10 mg/ml) and thymoquinone (0.125-1.0 mg/ml) were used for 5 to 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining. Furthermore, the components of the N. sativa essential oil were identified by gas chromatography/mass spectroscopy (GC/MS). Our study revealed that the essential oil of N. sativa at the concentration of 10 mg/ml and its main component, thymoquinone, at the concentration of 1 mg/ml had potent scolicidal activities against protoscolices of Echinococcus granulosus after 10 min exposure. Moreover, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%), and longifolene (6.1%) were found to be the major components of N. sativa essential oil by GC/MS analysis. The results of this study indicated the potential of N. sativa as a natural source for production of a new scolicidal agent for use in hydatid cyst surgery. However, further studies will be needed to confirm these results by checking the essential oil and its active component in in vivo models.