DEAD box RNA helicase 5 is a new pro-viral host factor for Sindbis virus infection.

BACKGROUND: RNA helicases are emerging as key factors regulating host-virus interactions. The DEAD-box ATP-dependent RNA helicase DDX5, which plays an important role in many aspects of cellular RNA biology, was also found to either promote or inhibit viral replication upon infection with several RNA viruses. Here, our aim is to examine the impact of DDX5 on Sindbis virus (SINV) infection. METHODS: We analysed the interaction between DDX5 and the viral RNA using imaging and RNA-immunoprecipitation approaches. The interactome of DDX5 in mock- and SINV-infected cells was determined by mass spectrometry. We validated the interaction between DDX17 and the viral capsid by co- immunoprecipitation in the presence or absence of an RNase treatment. We determined the subcellular localization of DDX5, its cofactor DDX17 and the viral capsid protein by co-immunofluorescence. Finally, we investigated the impact of DDX5 depletion and overexpression on SINV infection at the viral protein, RNA and infectious particle accumulation level. The contribution of DDX17 was also tested by knockdown experiments. RESULTS: In this study we demonstrate that DDX5 interacts with the SINV RNA during infection. Furthermore, the proteomic analysis of the DDX5 interactome in mock and SINV-infected HCT116 cells identified new cellular and viral partners and confirmed the interaction between DDX5 and DDX17. Both DDX5 and DDX17 re-localize from the nucleus to the cytoplasm upon SINV infection and interact with the viral capsid protein. We also show that DDX5 depletion negatively impacts the viral replication cycle, while its overexpression has a pro-viral effect. Finally, we observed that DDX17 depletion reduces SINV infection, an effect which is even more pronounced in a DDX5-depleted background, suggesting a synergistic pro-viral effect of the DDX5 and DDX17 proteins on SINV. CONCLUSIONS: These results not only shed light on DDX5 as a novel and important host factor to the SINV life cycle, but also expand our understanding of the roles played by DDX5 and DDX17 as regulators of viral infections.

Assessment of plant growth promoting bacteria strains on growth, yield and quality of sweet corn.

The use of plant growth promoting bacteria (PGPB) is increasingly gaining acceptance from all the stakeholders of the agricultural production. Different strains of PGPB species had been found to have a vast variety of mechanisms of action, while at the same time, affect differently a variety of crops. This study investigated the effectiveness of ten PGPB strains, on sweet corn cultivation under Mediterranean soil and climatic conditions. A field experiment that followed a completely randomized design was conducted at the region of Attica at Oropos. The results indicated that B. mojavensis increased yield by 16%, B. subtilis by 13.8%, B. pumilus by 11.8% and B. pseudomycoides by 9.8% compared to control. In addition, the harvested grains of the plants treated with B. mojavensis, B. subtilis and B. pumilus presented the highest values of protein and fiber content. Moreover, in most of the cases, high values of photosynthetic rate, transpiration rate and stomatal conductance during the cultivation period, resulted in high productivity. Regarding the texture, the size, the sphericity and the ash content of corn grains, it was found that they were not influenced by the application of different treatments of PGPB. The use of certain strains of PGPB, under specific soil and climatic conditions could contribute to better understand which strains are better suited to certain crops.

Evaluation of Plant Growth Promoting Bacteria Strains on Growth, Yield and Quality of Industrial Tomato.

Plant growth promoting bacteria (PGPB) are used as biostimulants to improve the growth and yield as well as the quality of crops. In the present study, nine strains of PGPB and one solid mix consisting of two of them were evaluated on the cultivation of industrial tomato under specific soil and climatic conditions. The results showed that Bacillus licheniformis treatment increased dry weight of the tomato plants by 39%, and the photosynthetic rate was increased by Priestia megaterium 9.9%. The application of Bacillus subtilis, Bacillus amyloliquefaciens, Priestia megaterium, and Bacillus licheniformis increased mean fruit weight per plant 26.78-30.70% compared to that of control. Yield per plant was increased 51.94% with the use of Bacillus licheniformis compared to that of control. The quality of the fruits in nearly every bacteria strain was improved. Bacillus pumilus and the mix of Priestia megaterium and Azotobacter chroococcum (1:1) increased the most total soluble solids in the tomato fruits (4.70° Brix), and Priestia megaterium increased content in lycopene and total carotenoids by 52.8% and 25%, respectively; Bacillus pseudomycoides increased Pectin methylesterase (PME) activity (24.94 units/mL), and Bacillusmojavensis, along with the mix of Priestia megaterium and Azotobacter chroococcum, increased Poligalacturonase (PG) activity the most (30.09 and 32.53 units/mL, respectively). Most of the bacteria strains presented an increased antioxidant activity significantly better that that of the control up to 31.25%. The results of this study confirmed that the use of PGPB as biostimulants can improve the yield and the quality of industrial tomato.

Effect of foliar and soil application of plant growth promoting bacteria on growth, physiology, yield and seed quality of maize under Mediterranean conditions.

The use of plant growth promoting bacteria (PGPB) as biostimulants favors the increase of crop productivity and the improvement of yield quality. The main objective of the present study was to investigate the effect of the PGPB biostimulants (Azotobacter chroococcum, Bacillus subtilis, Bacillus megatherium and their mixes) and the application method (foliar and soil) on the growth, the physiology, the yield and the quality of maize. The obtained results showed that A. chroococcum treatment increased the chlorophyll content up to 6.1%, the photosynthetic rate up to 18.4% and the transpiration rate up to 34.3%. The highest maize yields were performed by the treatments B. megatherium (244.67 g) and the mix of A. chroococcum and B. subtilis (1:1) (243.67 g) when applied on the soil. The Soil application of the PGPB resulted in increased yield of maize from 5.5 to 13.4% compared to control treatment. Concerning quality characteristics, B. subtilis treatment increased total solids content in harvested maize seeds by 92%, as well as crude fiber content by 46% compared to control. The results confirmed that the use of PGPB could contribute as a new cultivation practice for sustainable growth, productivity and quality of grain crops.

Electrocardiographic criteria which have the best prognostic significance in hypertensive patients with echocardiographic hypertrophy of left ventricle: 15-year prospective study.

BACKGROUND: Electrocardiography is the first-choice technique for detecting left ventricular hypertrophy in patients with arterial hypertension. It is necessary to know the probable outcome for every patient during the treatment, with the aim of improving cardiovascular event prevention. HYPOTHESIS: Certain electrocardiographic criteria for left ventricular hypertrophy may predict outcomes of patients with left ventricular hypertrophy during a 15-year follow-up. METHODS: Fifteen-year prospective study of 83 consecutive patients (53 male and 30 female; mean age 55.3 ± 8.1) with echocardiographic left ventricular hypertrophy (left ventricular mass index 170.3 ± 31.6 g/m2 ). Electrocardiographic left ventricular hypertrophy was determined by means of Gubner-Ungerleider voltage, Lewis voltage, voltage of R wave in aVL lead, Lyon-Sokolow voltage, Cornell voltage and Cornell product, voltage RV6 and RV5 ratio, Romhilt-Estes score, Framingham criterion and Perugia criterion. RESULTS: One or more composite events were registered in 32 (38.5%) patients during 15-year follow-up. Positive Lyon-Sokolow score (17.6% vs. 47.3%; P < 0.05), Lewis voltage (9.8% vs. 21.9%; P < 0.05), Cornell voltage (15.7% vs. 37.5%; P < 0.05), and Cornell product (9.8% vs. 34.4%; P < 0.01) were more frequent in a group of patients with composite events. Odd ratio for Cornell product was 4.819 (95% CI 1.486-15.627). CONCLUSION: Patients with echocardiographic left ventricular hypertrophy who had positive Lewis voltage, Lyon-Sokolow voltage, Cornell voltage, and Cornell product showed worse 15-year outcome. The strongest predictor of cardiovascular events was positive result of Cornell product.