Early physiological response of potato plants to entomopathogenic fungi under hydroponic conditions

Endophytic entomopathogenic fungi are promising agents for the promotion of plant growth, the activation of immunity, and protection against phytopathogens. However, physiological changes in plants after treatment with fungi are insufficiently studied. We investigated the effect of potato inoculation with conidia from Metarhizium robertsii and Beauveria bassiana on the growth (fresh and dry weight, length of shoots and roots, counts of stolons and leaves, and total surface area of leaves) and physiological parameters (pigment contents, free proline and malondialdehyde content, and activity of antioxidant enzymes) at the initial stage of the plant–fungus interaction (seven days) under hydroponic conditions. The results showed that the fungi could act as an immune-modulating factor for plants based on the increase in malondialdehyde and proline contents. At the same time, we observed growth retardation and a decrease in the content of photosynthetic pigments, which may be caused by a tradeoff between plant growth and the immune response

Evaluation of the metabolism properties of choline kinase alpha in neoplasms of the parathyroid glands. A pilot study

BACKGROUND: Primary hyperparathyroidism (PHPT) is a widespread endocrine disease characterized by excessive production of parathyroid hormone (PTH) due to parathyroid gland hyperplasia (PGH) or tumor lesions (adenoma or cancer of the parathyroid gland (PG) in 80% and 1–5% of cases respectively). Choline kinase α–alpha (XKα) overexpression is described in tumors of different localization, but there is no data on its expression in PG tumors. AIMS: To study the character of XKα expression in PG neoplasms and its relationship with clinical, laboratory, and visualization characteristics (positron emission tomography combined with computed tomography (PET/CT) with 18F–fluorocholine (18F–FC)). MATERIALS AND METHODS: The material for the study was based on tissue samples from 10 patients of 34–70 years old (Me = 61.5; [48; 66]), with a laboratory–confirmed diagnosis of PHT. An immunohistochemical study (IHC) was carried out on materials from 2 patients with hyperplasia of the main cells, from 5 patients with adenoma of PG, from 1 patient with atypical adenoma and 1 with carcinoma of PG; in 1 case the metastasis of cancer of the neck with lymph node was examined. RESULTS: The expression of XKα is spotted in all types of PG cells (chief cells: active and inactive forms), transitional forms between the chief cells and oxyphil; oxyphil cells, but it was most intense in active chief cells. The expression of XKα was observed in neoplasms of PG of various degrees of malignancy. In the most numerous group of PG formations with a favorable prognosis (11 samples from 7 patients), no statistically significant correlation (p> 0.05) was obtained between the intensity expression of the XKα, of the PTH and the proliferative activity index Ki–67, the level of radiopharmaceutical accumulation in PET/CT with 18F–FC (SUVmax) and laboratory data (PTH, Ca, Ca++). CONCLUSIONS: In the majority of investigated cases, moderate and intensive expression of the XKα was detected in PG cells. A small amount of studied cases does not allow us to identify the connection between the intensity of XKα expression and the malignant potential for the formation of PG

Fungus Metarhizium robertsii and neurotoxic insecticide affect gut immunity and microbiota in Colorado potato beetles

Fungal infections and toxicoses caused by insecticides may alter microbial communities and immune responses in the insect gut. We investigated the effects of Metarhizium robertsii fungus and avermectins on the midgut physiology of Colorado potato beetle larvae. We analyzed changes in the bacterial community, immunity- and stress-related gene expression, reactive oxygen species (ROS) production, and detoxification enzyme activity in response to topical infection with the M. robertsii fungus, oral administration of avermectins, and a combination of the two treatments. Avermectin treatment led to a reduction in microbiota diversity and an enhancement in the abundance of enterobacteria, and these changes were followed by the downregulation of Stat and Hsp90, upregulation of transcription factors for the Toll and IMD pathways and activation of detoxification enzymes. Fungal infection also led to a decrease in microbiota diversity, although the changes in community structure were not significant, except for the enhancement of Serratia. Fungal infection decreased the production of ROS but did not affect the gene expression of the immune pathways. In the combined treatment, fungal infection inhibited the activation of detoxification enzymes and prevented the downregulation of the JAK-STAT pathway caused by avermectins. The results of this study suggest that fungal infection modulates physiological responses to avermectins and that fungal infection may increase avermectin toxicosis by blocking detoxification enzymes in the gut

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Comparative analysis of the immune response of the wax moth Galleria mellonella after infection with the fungi Cordyceps militaris and Metarhizium robertsii

Entomopathogenic fungi form different strategies of interaction with their insect hosts. The influence of funga

The effect of population density of Lymantria dispar (Lepidoptera: Erebidae) on its fitness, physiology and activation of the covert nucleopolyhedrovirus

After high population densities of insect defoliators there is often a dramatic decrease in their abundance due to various limiting factors. Here, we compared gypsy moth larvae (Lymantria dispar L.) reared singly and in crowded conditions. We compared a number of physiological parameters of these insects and the effect of L. dispar population density on the activation of covert baculovirus infections in the larvae. It was found that the population density of gypsy moth larvae did not affect the mortality due to the activation of the covert virus infection or the total mortality. On the other hand, solitary-reared larvae were heavier, took longer to develop, and showed a four-fold higher concentration of dopamine in their haemolymph than larvae reared in groups. Thus, we demonstrated that an increase in the population density of larvae per se facilitates some changes in fi tness and innate immunity traits but is not related to the activation of covert baculovirus infection. We suggest that an increase in population density does not increase the risk of epizootics triggered by the activation of covert baculovirus infection and that researchers should pay more attention to studying density-associated factors, such as starvation

Orthosteric and/or Allosteric Binding of α-Conotoxins to Nicotinic Acetylcholine Receptors and Their Models

α-Conotoxins from Conus snails are capable of distinguishing muscle and neuronal nicotinic acetylcholine receptors (nAChRs). α-Conotoxin RgIA and αO-conotoxin GeXIVA, blocking neuronal α9α10 nAChR, are potential analgesics. Typically, α-conotoxins bind to the orthosteric sites for agonists/competitive antagonists, but αO-conotoxin GeXIVA was proposed to attach allosterically, judging by electrophysiological experiments on α9α10 nAChR. We decided to verify this conclusion by radioligand analysis in competition with α-bungarotoxin (αBgt) on the ligand-binding domain of the nAChR α9 subunit (α9 LBD), where, from the X-ray analysis, αBgt binds at the orthosteric site. A competition with αBgt was registered for GeXIVA and RgIA, IC50 values being in the micromolar range. However, high nonspecific binding of conotoxins (detected with their radioiodinated derivatives) to His6-resin attaching α9 LBD did not allow us to accurately measure IC50s. However, IC50s were measured for binding to Aplysia californica AChBP: the RgIA globular isomer, known to be active against α9α10 nAChR, was more efficient than the ribbon one, whereas all three GeXIVA isomers had similar potencies at low µM. Thus, radioligand analysis indicated that both conotoxins can attach to the orthosteric sites in these nAChR models, which should be taken into account in the design of analgesics on the basis of these conotoxins