Authors:S. Popovski, K. Kos, B. Jakovac Strajn, and F.A. Celar
The genus Fusarium consists of multiple diverse species, which, as a result of their frequency in nature and pathogenicity, are significant in agriculture, as well as in human and veterinary medicine. In the course of field trials, by using standard phytopathological methods, and performing analyses of 19 different varieties of wheat and a portion of infected grains gathered from two distinct locations in Slovenia, we have determined the presence of various phytopathogenic species of the genus Fusarium. Because of the reliability, the experiment was performed in two consecutive years, 2012 and 2013. A laboratory analysis was conducted with an ELISA test on all grain samples for the determination of deoxynivalenol (DON) concentration. The results show that the main differences in the infection levels (F. culmorum + F. graminearum; FC + FG) of wheat samples were found in Jable (humid area), at the same time showing higher levels of DON content than Rakičan (dry area). Such a statement is supported by correlation test, where correlation is evident between FC + FG and DON in every variation. The data for both wheat types (awned and awnless) together showed that the grain in Jable is statistically significant more infected by FC + FG when compared to that in Rakičan. Moreover, our descriptive analysis confirms that the infection rate of grain with FC and FG shows a strong correlation with the emergence of DON.
Authors:J. Schmid, K. Hoenes, M. Rath, P. Vatter, B. Spellerberg, and M. Hessling
In this study, the photoinactivation of Legionella by visible light is investigated. The success of this approach would offer new prospects for technical water disinfection and maybe even for therapeutic measures in cases of Legionella infections. Therefore, Legionella rubrilucens was dispensed on buffered charcoal yeast extract medium agar plates and illuminated with different doses of violet light generated by 405 nm light-emitting diodes (LEDs). A strong photoinactivation effect was observed. A dose of 125 J/ cm2 reduced the bacterial concentration by more than 5 orders of magnitude compared to Legionella on unirradiated agar plates. The necessary dose for a one log-level reduction was about 24 J/cm2. These results were obtained for extracellular L. rubrilucens, but other Legionella species may exhibit a similar behavior.
Authors:H. Mahmoudi, M. Salari, M. Ghayeb Zamharir, and M. Ghorbani
A safflower disease was observed in the fields of South Khorasan (Iran) in 2017–2018. Affected plants had extensive fasciation, bushy growth, small leaves, phyllody and shortened internodes. Polymerase chain reaction (PCR) assays were performed using universal phytoplasma primers pairs P1/P7, R16mF1/mR1 and M1/M2 to detect putative phytoplasma (s). Nested PCR analyses showed that all symptomatic plants were positive for phytoplasma infection, while asymptomatic plants were negative. Nucleotide sequence analysis and RFLP analyses of PCR-amplified 16S rDNA sequences indicated that safflower fasciation in Iran was associated with a phytoplasma that belonged to the peanut witches' broom group (16SrII). Phylogenetic analysis confirmed that safflowers fasciation phytoplasma (SaP) must be classified in ‘Candidatus phytoplasma aurantifolia’ (16SrII) taxonomic group. To our knowledge, this is the first documentation of a phytoplasma associated with safflower fasciation in Iran and the world.
We compared the haematological and biochemical values within a population of yellow-legged gulls (Larus michahellis) in the Chafarinas Islands (Northern Africa), in non-breeding (February) and breeding (May) animals. We collected blood samples from 51 adults. We found that according to the haematological data, there was a significant variation in haemoglobin content, and a higher proportion of heterophils, thrombocytes, and Haemoproteus infection in breeding individuals with a lower level in basophils. Blood biochemistry showed a higher level in plasmatic proteins, calcium, phosphorus, thiobarbituric acidreactive substances and alkaline phosphatase as well as alanine aminotransferase activity in breeding animals while cholesterol and phospholipid levels showed a lower level. There was also a sexual difference in triglycerides, albumin, thiobarbituric acid-reactive substances and alkaline phosphatase activity. Hence, the haematological and blood chemistry values of yellow-legged gulls showed some differences between breeding and non-breeding individuals as well as between sexes.
The recent review summarizes the major achievements in discovery of role of phytoglobins in mediation of nitric oxide generated cellular functions in higher plants. Genes encoding non-symbiotic hemoglobins have been cloned from several plant species. The expression pattern of these genes show tissue-specificity that is also under the control of stress factors like hypoxia. The nitric oxide has pivotal role in signalling pathway specifically in hypersensitive reactions and programmed cell death. Production of transgenic tobacco plants overexpressing the alfalfa hemoglobin showed altered necrotic symptoms after treatment with nitric oxide generating compounds or infection by necrotic pathogens. The present review helps to outline the similar relation between hemoglobin and nitric oxide in plants as it was found in animal cells.
Authors:J. Palazzini, V. Fumero, N. Yerkovich, G. Barros, M. Cuniberti, and S. Chulze
Fusarium graminearum (Schwabe) is reported as the main causal agent of Fusarium head blight in Argentina. The disease causes great losses in humid and semi-humid regions of the world, reducing grain yield and quality. During 2012/13 harvest season, a severe epidemic occurred in Argentina. The aims of this work were to determine the F. graminearum incidence and deoxynivalenol accumulation in wheat grain and flour samples obtained from two of the main wheat growing regions from Argentina. Levels of the pathogen and deoxynivalenol content were correlated in heads, grains and flour. Out of 69 wheat grain samples, 55 (79.7%) showed deoxynivalenol levels between 0.4 and 8.5 μg/kg. Fusarium graminearum was the main species isolated, the isolation frequency ranged from 30 to 52% of the total grains analyzed. Correlations were observed between deoxynivalenol content, % of F. graminearum infection, presence of the pathogen in heads, grain and flour.
Authors:P. Kannan, B. Shanmugavadivu, C. Petchiammal, and W. Hopper
Wrightia tinctoria leaf hexane, methanol and ethanol extracts were screened against skin bacteria and dermatophytes by in vitro. The extracts were tested using agar dilution method and broth micro dilution method. Methanol and ethanol extracts showed antibacterial activity; the MIC was 0.5 mg/ml for Bacillus subtilis and Staphylococcus epidermidis; 0.25 mg/ml for Staphylococcus aureus. The hexane extract showed antifungal activity against Trichophyton rubrum and Trichophyton tonsurans at 2 mg/ml. The MIC of 2 mg/ml was observed for methanol extract against Trichophyton mentagrophytes and IC50 (2 mg/ml) was determined for Trichophyton rubrum and Epidermophyton floccosum. To summarise Wrightia tinctoria leaves possessed potent antimicrobial properties against dermatophytic microbes. In particular, methanol and ethanol extracts were active against bacteria and hexane extract was active against dermatophytic fungi, suggesting that the active principles may be useful in the topical treatment of superficial skin infections.