نشریه زیست شناسی کاربردی
سال سی و پنجم شماره 2 (تابستان 1401)

Discovering and describing the critical role of proteins in contrast to disease and defects causing by their inactivity is a major interest for scientific studies. Amyloid aggregation and the diseases caused by them, known as neurodegenerative diseases, reveal new aspect of proteins roles in pathogenicity. Due to lack of clear treatment to these age-related diseases, prevention of amyloid formation would be the most practical way to deal with them.

In this research, we analyzed the effects of Heracleum persicum Desf. ex Fisch., C.A.Mey. & Avé-Lall. and Nigella sativa L. alcoholic extracts on insulin amyloid formation. Human insulin (HI) amyloid formation was analyzed under specific pH and temperature conditions by Thioflavin T (ThT) assay and scanning electron microscopy (SEM) while treating with different concentrations of H. persicum and N. sativa alcoholic extracts.

Our results reveal that the alcoholic extracts of H. persicum and N. sativa have significant preventing effects on HI amyloid formation. Considering the long history of these medicinal plant usage in Iranian and Islamic cultures and the presence of antioxidant and anticonvulsant compounds in them, and according to the data obtained from this study, we strongly suggest that these two herbs are suitable candidates as sources of amyloid aggregation prevention compounds.

Although nickel is an essential element for plants, it has toxic effects at high concentrations. White clover (Trifolium repens) is a widely cultivated forage crop with high biomass. On the other hand, nickel pollution on farms has increased. Accordingly, in this study, the effects of nickel treatments (at 0, 10, 50, 100, 200, 500, and 1000 μM levels) were investigated on seed germination characteristics of the plant in a growth chamber and then on biochemical and physiological parameters in hydroponic culture, in a completely randomized statistical design. The results showed that seed germination, percent and speed, seed vigor, and seedling length increased and decreased with low and high levels of nickel, respectively. Seedlings' death was observed at 100 μM and higher concentrations of nickel. Concentrations of 10 and 50 μM of nickel harmed biochemical parameters including chlorophyll, carbohydrate, protein, and peroxidase activity and raised the amounts of carotenoids. By increasing levels of nickel treatments, roots, and shoots nickel concentrations increased. In comparison to the control, treatments of 10 and 50 μM nickel concentrations led to an increase and decrease in stem dry weight, shoot length, leaf area, and leaf dry weight, respectively. It seems that 10 μM and 50 μM concentrations of nickel function as suitable and toxic levels for the growth of this plant, respectively. It also seems that white clover is a nickel-sensitive plant and not able to tolerate and accumulate nickel, and it is not a proper candidate for phytoremediation.

Rutilus is one of the most important genera of the Leuciscidae family, whose members are distributed from Eastern Siberia to Western Europe. It has always been difficult for researchers to identify the species and populations of this genus due to the similarity of morphologic characters and the existence of intermediate populations. Although several studies conducted base on morphology characters of members of this genus, the molecular systematic and phylogeny of Rutilus in the southern Caspian Sea have not been studied. Therefore, in order to investigate the status of Rutilus members in the southern Caspian Sea, a study was performed using the COI gene sequence. Samples of members of this genus were purchased from the of beach of Bandar-e-Turkmen, Bandar-e-Gaz, Babolsar, Nour, Ramsar, Bandar-e-Anzali and Astara. After amplifying the COI gene, the fragment was sequenced. Using the sequences results and other sequences in the NCBI gene bank, phylogeny trees were plotted by the Bayesian inference method, Maximum likelihood estimation, and haplotype network. According to the results, the sequenced specimens from the southern basin of the Caspian Sea were placed in the R. frisii clade. Also, the presence of R. rutilus and R. kutum species in the studied areas was not confirmed. Due to the insignificant difference in COI gene and phenotypic diversity, it seems the differences due to ecological plasticity, tolerance to salted waters coupled degrees of salinity, having resident and migratory populations among members of this genus.

Seed production is one of the key factors in the seed regeneration of plants and trees and is widely used in regeneration, forest development, afforestation and especially seedling production in nurseries. Therefore, it is very important to select quality and ripe seeds with suitable physical shape. The aim of this study was to investigate the effect of altitude factor on the physical properties of pistacia seeds in Sustan Reserve, which is one of the four pistacia reserves in West Azerbaijan Province. The reserve was divided into 4 altitude classes including 1515, 1615, 1715and 1815 meters above sea level. Also, in order to increase the altitude, the reserve area was divided into one-hectare sample plots (100 m * 100 m) In each sample piece, Three seed-giving trees including the diameter, the smallest diameter and a medium diameter were selected (Slope, direction and soil factor were equalized). A total of 60 trees were selected and 5 clusters from each tree were randomly collected in the north, south, east, west and center of the crown and the physical characteristics of the seeds included: cluster length, ‌ number of fruits per cluster, fruit length, fruit width, Fruit weight, grain weight and seedlessness percentage in each altitude class were evaluated. Data were analyzed using Excel and SPSS software and the means were compared and the analysis of variance was performed using F-test, Duncan multiple comparison test and Kruskal-Wallis test. The results showed that all traits except the percentage of seedless at different altitudes above s

The combination of biological and chemical insecticides is very important to control wheat thrips ‎and reduce the dose of chemical insecticides. Therefore, in this study, insecticidal activity of botanical ‎‎(Tondexir and Palizin) and microbial pesticides (Bacillus thuringiensis (B.t)) in comparison with chemical ‎‎(Thiacloprid and Thiacloprid+Deltamethrin) insecticides on wheat thrips was investigated.‎‏ ‏A completely ‎randomized experiment was performed with three replications and five concentrations of each insecticide. ‎Based on the lowest LC50, a chemical insecticide and a botanical insecticide were selected. Their LC15 and ‎LC30 concentrations were combined with microbial insecticide and 48 h later, the mortality was calculated. ‎Mortality increased with increasing concentrations of chemical and botanical insecticides. The lowest ‎amount of LC50 was related to Thiacloprid+Deltamethrin and Palizin which were used in combination with ‎microbial insecticide. The highest mortality (76.67%) was related to the combination treatment of ‎B.t+Thiacloprid+Deltamethrin LC15, which can be recommended after field studies as a alternative‏ ‏of ‎chemical insecticides‏ ‏to protect wheat against thrips.‎

This study was done to investigate the effects of gamma irradiation on lethal dose 50% (LD50) of honey bee venom.

Venom samples were irradiated at doses of 0,2,4,6 and 8 kGy . Malondialdehyde level and true protein concentration were determined pre- and post-irradiation. Protein subunits of venom was detected by polyacrylamide gel electrophoresis. Allergen compounds were measured using HPLC technique. Lethal dose 50% (LD50) was determined using in vivo trial. Eighty hamsters were allocated to 5 treatments and 4 replicates in a CRD design. Venom solution at dose of 0.5, 0.75, 1 and 2 mg/Kg BW were injected intra peritoneal and mortality recorded then LD50 was computed by Spearman–Karber method. In the final of study, hamsters liver samples collected and fixed in 10% formalin. Liver samples were sliced, fixed and stained by hematoxylin and eosin. Data were analyzed by SAS Software.

The results showed that true protein content and malondialdehyde level in irradiated samples had no differ with the control group (P>0.05). Electrophoresis patterns and HPLC results showed that irradiation at doses of 4 and 6 kGy decreased phospholipase amount and increase the low subunits of protein (P<0.05). Irradiation at doses of 6 and 8 kGy increased LD50 by 34%. Based on the histology results, irradiation of honey bee venom at dose of 4 and 6 kGy could decrease the inflammation of hepatocytes and vein hyperemia in liver.

Irradiation at dose of 6 kGy by removing allergens can be used to reduce the toxicity of bee venom.

Owing to the high cytotoxicity, introduction of anticancer pharmaceuticals to the encironment via pharmaceutical and hospital effluents is regarded a major health threat for eukaryotes. Exploring bacterial cells, as prokaryotic organisms, could be a novel approach for the removal of these compounds. Therefore, in this study, we aimed to isolate and identify oxaliplatin degrading bacteria from pharmaceutical wastewater samples and to evaluate their oxaliplatin removal potential as single and multi-species systems.

Bacterial isolation was performed using the membrane filtration method and the inhibitory effect of the drug for the isolated bacteria was evaluated in 96-well plates. Finally, oxaliplatin removal efficacy of the single and multi-species bacterial populations was determined using the High-Pressure Liquid chromatography (HPLC).

A total number of five bacterial species, including Enterobacter agglomerans, Citrobacter youngae, Xenorhabdus nematophilis, Bacillus lichineformis and Moraxella spp.able to degrade oxaliplatin were isolated. The highest and least oxaliplatin degrading potential was observed for B. lichiniformis (52%) and E. agglomerans (21%), respectively. Also, the multi-species treatment containing B. lichineformis, X. nematophilis, E. agglomeran showed the highest oxaliplatin removal efficacy (79%).

This work reveals that the bacteria isolated from pharmaceutical effluents could be employed for oxaliplatin removal and could be considered as a novel approach for the reduction of pharmaceutical pollutants.

To evaluate the chilling tolerance of three commercial kiwifruit cultivars (Hayward, Golden and Red) this study was carried out as a factorial experiment using randomized block design with three replications from January to May, 2019. The first factor was kiwifruit cultivars that included three cultivars of Hayward, Golden and Red; the second factor was 3 levels of chilling [including: b1) 4 ºC, b2) -6 ºC and b2) -16 ºC] and the third factor was three phonological stages of kiwifruit cultivars including: dormancy of buds, swelling of buds and fruit-set stages. The evaluated traits included Na, K, Ca, Mg, electrolyte leakage and proline. The results revealed that Ca, Mg, electrolyte leakage index and proline content of fruit-set stage were the highest and in the dormant buds and the swelling bud stage, the difference were not statistically significant. According to the results, the highest amounts of Ca and proline content were obtained at -6 ° C. The results also showed that the highest proline content and the lowest electrolyte leakage were related to Golden cultivar. Since increasing the electrolyte leakage shows the sensitivity to cold stress, so it can be concluded that Golden cultivar was more resistant to cold than the other examined cultivars.

Lepidium draba peroxidase (LDP) belonging to the class III plant peroxidases that its amino acid sequence shows over 90% similarity with horseradish peroxidase (HRP).

In this study, after expression and purification of LDP, its immobilization conditions were optimized on the Zinc metal-organic framework (Zn-MOF) using glutaraldehyde as a cross-linking agent for firm binding. Then physicochemical properties, kinetic parameters and stability of the immobilized enzyme were compared with the free one.

The best conditions for enzyme immobilization with 67% yield were optimized at concentration of 0.02 g of Zn-MOF, 0.75mg/ml and 1.2 dM of glutaraldehyde, after 3h incubation. The results showed that the specific activity of the immobilized enzyme increased more than doubled that of free enzyme and its Km was reduced by 49% compared to the free one for TMB substrate. Also its kinetic stability reduced against pH and temperature in compared to the free enzyme.

Conventional morphological identification methods, although reasonably effective in identifying different species of Aspergillus, are generally ineffective in identifying the races and populations of Aspergillus species; it is also true about Aspergillus flavus, which is one of the most important Aspergillus species in Economic and health. In this study, in addition to morphological identification based on microscopic and macroscopic traits of Aspergillus flavus isolates from five dried fruit products, Twenty standardized primers based on ISSR method were used to study the populations of this species. Statistical Multivariate analyzes based on ISSR findings, show different populations from different sources and different locations of Aspergillus flavus can be distinguish from each other with use of this method.