Investigations of mycoviruses from Leptosphaeria species and their effects on pathogenicity

The aims of this research were to assess the incidence of dsRNA viruses in five different plant pathogenic fungi, including Hymenoscyphus fraxineus, Dothistroma septosporum, Leptosphaeria species (Leptosphaeria maculans and Leptosphaeria biglobosa) and Pyrenopeziza brassicae, as their incidence has not been reported previously in these species, and then to investigate the effects of mycoviruses on the growth and pathogenicity of the fungi. Hence, 57 L. maculans and 16 L. biglobosa isolates were screened and 11 L. biglobosa isolates possessed dsRNA elements while only one of the 45 D. septosporum isolates was found to contain a mycovirus subsequently identified as a chrysovirus. In contrast, none of the 162 H. fraxineus and 10 Pyrenopeziza brassicae isolates appeared to contain dsRNA elements. Further research was carried out on L. biglobosa because of the excellent recovery of dsRNA elements and the fact that it is also responsible for causing phoma stem canker which is an economically important disease of oilseed rape worldwide. However, not only L. biglobosa but also the more damaging L. maculans causes phoma stem canker. They are closely related and co-existing plant pathogens. Mycoviruses are a specific group of viruses that infect and replicate in fungi. They can be associated with hypovirulence or hypervirulence but are normally cryptic. Three different mycoviral dsRNAs were identified from L. biglobosa isolate C-Rox 12.8.1, ranging in size from ca. 4.0-4.9 kbp. Sequence analysis of LbMV-1 dsRNAs 1 and 2 revealed that they are most closely related to members of the family Totiviridae. However, attempts to characterise LbMV-1 dsRNA 3 failed. On the other hand, four mycoviral dsRNAs were identified from D. septosporum isolate D 752.1, ranging in size from ca. 2.8-3.5 kbp. Molecular characterisation of DsCV-1 showed that it is very similar to the chrysoviruses. To obtain information on the effects of dsRNAs on their host, cycloheximide treatment was used to eradicate dsRNA elements from L. biglobosa isolate W10. Subsequently, comparative growth experiments to assess radial growth and mycelial weight for virus-infected and virus-free W10 isolates were performed. These experiments showed that the LbMV-1 infection increased the growth of the fungus. To investigate the influence of mycoviruses on the pathogenicity of L. biglobosa, pathogenicity tests were performed using isogenic lines of the W10 isolate inoculated onto oilseed rape cotyledons and disease symptoms were analysed at different time periods; mycoviruses were found to increase fungal pathogenicity. In addition to this, effects of pre-treatment of B. napus leaves with conidia of virus-infected or virus-free L. biglobosa on infection by conidia of L. maculans and development of disease (phoma leaf spot) were studied in a controlled-environment conditions. Pre-treatment of first true leaves with virus-infected L. biglobosa decreased the phoma leaf spot lesion area on second true leaves (systemic effect) as compared to pre-treatment with virus-free L. biglobosa

Sequence determination of a satellite RNA isolated from Aspergillus foetidus

Aspergillus foetidus virus (AfV) has at least two distinct particle types, designated as AfV-fast (F) and AfV-slow (S). AfV-S includes AfV-S1, a victorivirus; AfV-S2, an unclassified satellite RNA; and AfV-S3, a previously uncharacterized dsRNA element. Here, we describe the complete sequence of AfV-S3, which is a short non-coding RNA with no known homologs. AfV-S3 is predicted to form an extended secondary structure, shares a 5’ terminus with AfV-S2, and is a satellite RNA possibly dependent on both AfV-S1 and AfV-S2. This work concludes the sequencing of the A. foetidus viromePeer reviewe

Identification, Molecular Characterization, and Biology of a Novel Quadrivirus Infecting the Phytopathogenic Fungus Leptosphaeria biglobosa.

Here we report the molecular characterisation of a novel dsRNA virus isolated from the filamentous, plant pathogenic fungus Leptosphaeria biglobosa and known to cause significant alterations to fungal pigmentation and growth and to result in hypervirulence, as illustrated by comparisons between virus-infected and-cured isogenic fungal strains. The virus forms isometric particles approximately 40–45 nm in diameter and has a quadripartite dsRNA genome structure with size ranges of 4.9 to 4 kbp, each possessing a single ORF. Sequence analysis of the putative proteins encoded by dsRNAs 1–4, termed P1–P4, respectively, revealed modest similarities to the amino acid sequences of equivalent proteins predicted from the nucleotide sequences of known and suspected members of the family Quadriviridae and for that reason the virus was nominated Leptosphaeria biglobosa quadrivirus-1 (LbQV-1). Sequence and phylogenetic analysis using the P3 sequence, which encodes an RdRP, revealed that LbQV-1 was most closely related to known and suspected quadriviruses and monopartite totiviruses rather than other quadripartite mycoviruses including chrysoviruses and alternaviruses. Of the remaining encoded proteins, LbQV-1 P2 and P4 are structural proteins but the function of P1 is unknown. We propose that LbQV-1 is a novel member of the family Quadriviridae.Peer reviewe

Comparative study for inhibitoryeffect of Benzaldehyde Derivativeson the corrosionofAl in Hydrochloric Acid:Electrochemicaland theoretical investigation.

The investigation carried out for inhibitory effect of p-Aminophenol-N-Benzylidene (p-AmphNB) andp-Anisidine-N-Benzylidene (p-AnsNB) for pure Aluminium 1M HClby means of standard gravimetric (weight loss), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The values of  indicates the competitive Chemisorption and physisorption,Potentiodynamic polarization parameters revealed the mixed mode of inhibition with predominance of cathodic inhibition.The EIS showed linear correlation with concentration of inhibitor &Rctl while Cdlinversely correlated. Quantum chemical calculations based on density functional theory (DFT) method were performed on studied inhibitors. Correlation analysis concluded that the inhibition effect of inhibitors could be explained in terms of electronic properties.

Experimental Analysis of Friction Stir Welding of Dissimilar Alloys AA6061 and Mg AZ31 Using Circular Butt Joint Geometry

AbstractThe Aluminium alloy 6061 and Magnesium alloy AZ31 plates of 6mm thickness are welded in circular butt joint geometry by friction stir welding (FSW) process, using CNC vertical milling machine. Process parameters such as welding speed and tool rotational speed play an important role to obtain a better weld joint for dissimilar metals/materials. The friction stir welding tool is one of the critical components to the success of this process. It consists of a cylindrical shoulder and a pin with different geometry. In the experimental work, the said tool has been designed with cylindrical pin having four different geometries for friction stir welding of the dissimilar circular metal plates. Friction stir welding has been carried out at welding speed varying from 10 to 40mm/min and tool rotational speed from 800 to 2000rpm. Effects of process parameters on butt welded circular joint were investigated for weld strength. In this research work, it is found that welded joint between dissimilar metals alloys Al 6061 and Mg AZ31 can be formed using friction stir welding by selecting proper tool pin profile and welding parameters. It is suggested that friction stir welding of Aluminium alloy and Magnesium alloy with circular butt joint geometry would be useful in the future for automobile applications by getting the benefits from each material in a functional way

EVALUATION OF IN VITRO ANTICANCER ACTIVITY OF SYMPLOCOS RACEMOSA BARK AGAINST HEPATOCELLULAR CARCINOMA

Objective: To investigate in vitro anticancer activity of different extracts of bark of Symplocos racemosa against hepatocellular carcinoma.Methods: Different successive extracts of Symplocos racemosa bark were prepared using hexane, chloroform, ethyl acetate, n-butanol and water and were tested in vitro for cytotoxicity using (3-4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay in rat normal liver cells (BRL-3A) and human hepatocellular carcinoma (Hep3B) cells.Results: Ethyl acetate and chloroform extract of Symplocos racemosa exhibited cytotoxicity against human hepatocellular carcinoma (Hep3B) cells in vitro with IC50 value (µg/ml) of 63.45 and 75.55 respectively and not affected the normal liver (BRL-3A) cells.Conclusion: Symplocos racemosa bark extracts showed potential cytotoxic effects on human hepatocellular carcinoma cells. The anticancer activity exhibited by ethyl acetate and chloroform extract might be due to presence of phenolics and flavonoid constituents present in the bark. Ethyl acetate extract can further be explored for possible cytotoxic activity using in vivo models of liver cancer.Â

Prevalence of childhood asthma and its immediate outcome - At tertiary care rural hospital

Introduction: Asthma is a chronic inflammatory disorder of the airways resulting in episodic airway obstruction. Globally, childhood asthma is increasing in the prevalence, despite improvements in investigation and treatment. Childhood asthma seemed more prevalent in urban population and now even in rural areas of India. Objectives: To know the prevalence, assess the risk factors, severity, and immediate outcome of the treatment offered to asthmatic children in a tertiary rural hospital. Materials and Methods: All the diagnosed asthmatic children up to 18 years were enrolled in the study. All the patients of pulmonary Koch’s, congenital heart disease and chronic lung disease were excluded from the study. Clinical profile was noted in recruited patients. Results: The prevalence of childhood asthma among children visiting to our department was 3.93%. 58 (48.33%) had age of onset before the age of 6 years. Asthma was more prevalent in boys. 116 (96.66%) children presented with complain of cough, and 118 (98.33%) children had associated breathlessness. Common precipitating factors were change in season (71.66%), pollen allergy (58.33%), air pollutieon (45.00%), and passive smoking (23.33%). Exercise-induced asthma was seen in 55% cases, diurnal variation in 60% and 28.33% children had family history of atopic disease. Majority of the patient was undernourished. The average duration of stay in persistent asthma is 1.8 times more than in intermittent asthma. Conclusion: Significant number of patient becomes symptomatic before the 6 years of age. Prevention of child from exposure to passive smoking, environmental improvement, and allergen avoidance are major aspects for prevention of asthma exacerbations

Open appendicectomy stump: invaginate or not to invaginate?

Acute appendicitis remains the most common abdominal surgical emergency. Appendicectomy is the standard treatment of acute appendicitis, which performed by open or laparoscopic approach. During open method, after removal of appendix, stump simple ligation or simple ligation and invagination. A prospective randomized study conducted at Smt SCL General Hospital, Smt NHL municipal Medical College, Ahmedabad between October 2009 to September 2011 to evaluate the necessity of appendicular stump invagination during appendicectomy. A total 110 patients were studied and randomized into two group, Group I stump simple ligation, transfixation and invagination and Group II stump simple ligation and transfixation only. There was no statically significant difference in the rate of postoperative complication and post operative hospital stay between the two groups. The mean operating time was significantly shorter in group without invagination. The rate of postoperative paralytic ileus was more in group I. We conclude that simple ligation of the appendicular stump during appendicectomy is safe, simple and shortens operating time

Identification and sequence determination of a new chrysovirus infecting the phytopathogenic fungus Dothistroma septosporum

© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, to view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.A new double-stranded (ds) RNA mycovirus has been identified in isolate Ds752-1 of the phytopathogenic fungus Dothistroma septosporum, the causal agent of Dothistroma needle blight, also known as red band needle blight or pine needle blight. Dothistroma septosporum chrysovirus 1 (DsCV-1) is a new member of the genus Alphachrysovirus in the family Chrysoviridae. The DsCV-1 genome comprises four dsRNA elements designated 1, 2, 3, and 4 from largest to smallest. dsRNA1 encodes an RNA-dependent RNA polymerase (RdRP) that is most similar to the RdRP of Erysiphe necator associated chrysovirus 3. dsRNA2 potentially encodes two hypothetical proteins, one of which is small and has no homology to known proteins, and one of which is large with significant sequence similarity to the alphachryso-P3 of other alphachrysoviruses. dsRNA3 and dsRNA4 encode a coat protein (CP) and a putative cysteine protease, respectively. This is the first report of a mycovirus infecting the fungus D. septosporum, and DsCV-1 is one of three Chrysoviridae family members found to possess genomic dsRNAs potentially encoding more than one protein.Peer reviewe