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: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.
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: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:Kinga Hadzsiev, A. Tárnok, G. Kosztolányi, and K. Méhes
In a prospective study, the occurrence of malignancies in children referred to genetic counseling for congenital malformations, in their sibs, parents and grandparents was registered in 120 families by means of personal interviews. One hundred-and-twenty age matched subjects, admitted for acute respiratory infections or trauma, served as controls. No difference in the occurrence of tumors or leukemias between the two groups was found when the values of patients, sibs, and parents were compared. At the same time, the grandparents of probands with malformations had had significantly more malignancies than the grandparents of the controls. This may be explained by the fact that grandparents lived beyond the age of the usual onset of common cancers and leukemias.
Authors:W.J. Chi, Z.Y. Wang, J.M. Liu, C. Zhang, Y.H. Wu, and Y.J. Bai
Nitrogen (N) is an important nutrient for plant growth and yield production, and rice grown in paddy soil mainly uses ammonium (NH4+) as its N source. Previous studies have shown that N status is tightly connected to plant defense; however, the roles of NH4+ uptake and assimilation in rice sheath blight disease response have not been studied previously. Here, we analyzed the effects of different N sources on plant defense against Rhizoctonia solani. The results indicated that rice plants grown in N-free conditions had higher resistance to sheath blight than those grown under N conditions. In greater detail, rice plants cultured with glutamine as the sole N source were more susceptible to sheath blight disease compared to the groups using NH4+ and nitrate (NO3–) as sole N sources. N deficiency severely inhibited plant growth; therefore, ammonium transporter 1;2 overexpressors (AMT1;2 OXs) were generated to test their growth and defense ability under low N conditions. AMT1;2 OXs increased N use efficiency and exhibited less susceptible symptoms to R. solani and highly induced the expression of PBZ1 compared to the wild-type controls upon infection of R. solani. Furthermore, the glutamine synthetase 1;1 (GS1;1) mutant (gs1;1) was more susceptible to R. solani infection than the wild-type control, and the genetic combination of AMT1;2 OX and gs1;1 revealed that AMT1;2 OX was less susceptible to R. solani and required GS1;1 activity. In addition, cellular NH4+ content was higher in AMT1;2 OX and gs1;1 plants, indicating that NH4+ was not directly controlling plant defense. In conclusion, the present study showed that the activation of NH4+ uptake and assimilation were required for rice resistance against sheath blight disease.
Authors:W. Abera, H. Shimelis, J. Derera, M. Worku, and M. Laing
Productivity of maize (Zea mays L.) is curtailed by a number of stress factors, predominantly by diseases and insect pests. The Northern leaf blight disease of maize caused by Exserohilum turcicum (Pass.) Leonard and Suggs inflict significant yield losses in the humid tropical regions. The objectives of this study were to determine the leaf blight response of 50 elite maize inbred lines developed for the mid-altitude, sub-humid tropics and to select promising parents for resistance breeding. Inbred lines were evaluated in the field using a 5 × 10 alpha lattice design with three replications. Plants were artificially inoculated at the 4–6 leaf stages during 2011 and 2012. Data on disease severity and incidence, AUDPC and yields were recorded. Inbred lines had significant differences for E. turcicum reactions, and were classified into resistant, intermediate or susceptible categories. The mean disease severity ranged from 2.04% for the inbred line 136-a to 3.25% (Kuleni-C1-101-1-1-1). The upper leaf area infection of inbred lines 143-5-I and 136-a was 3.3%, while the line Kuleni-C1-101-1-1-1 displayed 100% infection. Further, 136-a developed the lowest AUDPC score at 238, whereas Kuleni-C1-101-1-1-1 had the maximum at 700. Overall, inbred lines CML202, 144-7-b, 139-5-j, 136-a, 30H83-7-1-1-1-2-1, ILoo’E-1-9-1-1-1-1-1 and 142-1-e, were identified as promising sources of resistance against E. turcicum. The selected elite inbred lines would be recommended for use in general varietal development, disease management and to enhance maize productivity, in the mid-altitude sub-humid tropics.
Authors:L. G. Puskás, L. Tiszlavicz, Zs. Rázga, L. L. Torday, T. Krenács, and J. Gy. Papp
. J., Bonora, E., Oberhollenzer, F., Muggeo, M., Xu, Q., Wick, G., Poewe, W., Willeit, J. (2001) Chronic infections and the risk of carotid atherosclerosis: Prospective results from a large population study. Circulation 103 , 1064