Using of GGE biplot in determination of genetic structure and heterotic groups in wheat (Triticum aestivum L.)

The present study was undertaken to analyze diallel data using GGE biplot model to gather information about genetic interrelationships among parents and identification of heterotic combinations for yield and yield components in bread wheat varieties. For this purpose, 8 bread wheat genotypes tested across in half-diallel crosses design, GGE biplot technique was used. Parents included the genotypes of Kouhdasht, Karim, Ehsan, Mehregan, N-92-9, Line 17, N80-19 and Atrak. The hybrids obtained from the one-way cross (28 hybrids) in agricultural years of 2016-17 were evaluated as randomized complete block design in two replications on the research farm of Gonbad Kavous University. The evaluated traits included the grain yield, weight of spike grains, number of grains in spike and number of spikes. Additive main effects and genotype × environment interaction (GGE) were employed in the evaluation of genotypes; analyses showed significant (P< 0.01) G × E, (genotype × environment interaction) with respect to plant seed yield. GGE biplot analysis showed that Karim was as the best general combiners for grain yield, number grain per spike and grain weight per spike, whereas Ehsan had the highest GCA effects for number of spikes. Ehsan and Karim had higher specific combining ability than other genotypes. The studied genotypes for this trait were divided into two heterotic groups where the first group included the genotypes of Kouhdasht, N-92-9, N80-19 and Atrak and the second group contained the genotypes of Line 17, Mehregan and Karim. Mehregan line had a weak combining ability with all testers and N-92-9 had also more power than others. Based on the biplot, the Karim genotype with high general adaptation was introduced as the ideal genotype in terms of grain yield, spike number, grain number per spike and grain weight, so the Karim genotype can be adapted to obtain high yield hybrids.

The effect of type II toxin-antitoxin systems on methicillinresistant Staphylococcus aureus persister cell formation and antibiotic tolerance

Persister cells are defi ned as a subpopulation of bacteria in a dormant state with the ability to reduce bacterial metabolism and they are involved in antibiotic tolerance. Toxin-antitoxin (TA) systems have been previously suggested as important players in persistence. Therefore, this study aimed to study the involvement of TA systems in persister cell formation in methicillin-resistant Staphylococcus aureus following antibiotic exposure. Using TADB and RASTA database, two type II TA systems including MazF/MazE and RelE/RelB were predicted in S. aureus. The presence of these TA genes was determined in 5 methicillin-resistant S. aureus isolates and the standard strain S. aureus subsp. aureus N315 using PCR method. To induce persistence, isolates were exposed to lethal doses of ciprofl oxacin and the expression of the studied TA system genes was measured after 5 h using Real-Time PCR. According to our results, all the studied isolates harbored the TA system genes. S. aureus was highly capable of persister cell formation following exposure to sub-MIC of ciprofl oxacin and RT-qPCR showed a signifi cant increase in the expression of the MazEF and RelBE loci, indicating their potential role in antibiotic tolerance. Considering the importance of antibiotic tolerance, further studies on persister cell formation and TA systems involved in this phenomenon are required to effi ciently target these systems.

TU-DAMD employment for molecular characterization of Salvia judaica and Salvia palaestina species

Genetic diversity in perennial Salvia judaica Boiss (Judean sage) and Salvia palaestina Benth (Palestinian sage) species using touch-up directed amplification of minisatellite region DNA (TU-DAMD) has been performed in two separated sets; in the first set (set A) the initial annealing temperature was increased from 50 °C to 55 °C, whereas, in the second one (set B), it increased from 55 °C to 60 °C by 0.5 °C/cycle during the first 10 PCR amplification cycles. Fifteen DAMD primers have been tested for each set. Set (A) produced 89.39% polymorphism level (P%) with polymorphic information content (PIC) average of 0.33 and marker index (MI) average of 3.96. Whereas, in set (B) these values were recorded to be 94.02%, 0.34 and 3.98 for P%, PIC and MI, respectively. Data showed that the two mentioned sets successfully highlighted high polymorphism level between the two studied Salvia sp. This work studies genetic diversity of S. judaica and S. palaestina species using TU-DAMD test as a novel molecular marker.

Insights on carbapenem-resistant Acinetobacter baumannii

Acinetobacter baumannii (A. baumannii) is an important nosocomial pathogen, which may be a causative agent in a wide-range of human pathologies. Carbapenems are usually considered the last safe and effective choice of drugs for the treatment of Gram-negative infections. The emergence of carbapenem-resistant A. baumannii (CRAB) is a critical public health issue as they leave clinicians with limited therapeutic options. In this study, phenotypic methods were used to characterize sixty-two (n = 62) A. baumannii isolates, which were included based on their suspected non-susceptibility to meropenem. Minimum inhibitory concentrations (MICs) of meropenem, levofloxacin, gentamicin, sulfamethoxazole/trimethoprim, tigecycline were determined using E-tests, while colistin MICs were determined using broth microdilution. The isolates were subjected to the modified Hodge test (MHT), the modified carbapenem-inactivation method (mCIM) and the imipenem/EDTA combined disk test (CDT). Efflux pump overexpression was studied using agar plates containing phenylalanine-arginine β-naphthylamide (PAβN). Assessment of biofilm-formation was carried out using the crystal violet tube-adherence method. 64.5% of the strains showed meropenem MICs in the resistant range (>8 mg/L), resistance rates were similarly high to the other tested antibiotics. The MHT and mCIM assay were positive in 79.0% and 67.7% of cases, respectively; the presence of an MBL was suggested for 29.0% of isolates. Efflux-pump overexpression was seen in 12.9% of isolates. 54.8% of the isolates were characterized as strong biofilm-producers. Microbiology laboratories have an important role in differentiating the distinct mechanisms by which these pathogens develop the CRAB phenotype, as plasmid-borne carbapenemases are significant from the standpoint of public health microbiology.

Action of Ganoderma lucidum mycelial growth filtrates on Erysiphe diffusa and embryotoxicity assessment in a chicken embryo model

This work aimed to evaluate the antimicrobial effect of Ganoderma lucidum mycelial growth filtrates (MGF) on the phytopathogen Erysiphe diffusa and their potential effects on the embryonic development of Gallus gallus. The antimicrobial activity was evaluated on E. diffusa spores by the microdilution broth method. To evaluate embryotoxic and teratogenic effects, fertile eggs of G. gallus received injections of solutions containing the filtrates of G. lucidum through the air chamber. After three days of incubation, we opened the eggs and evaluated egg viability, embryo survival, malformation occurrence, embryonic staging and heart rate. Live embryos were prepared using whole mount technique and the morphological analysis was performed. We used the generalized linear model to fit embryotoxicity and teratogenicity data. We verified that G. lucidum MGF showed inhibitory activity in vitro against E. diffusa and the minimum inhibitory concentrations ranged from 5 to 10 mg/mL. We could also observe that the filtrates did not present embryotoxic or teratogenic effects on the early embryonic development of G. gallus, but induced significant differences in the embryonic mean heart rate and on the stage of embryonic development.

Insights on carbapenem-resistant Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa) is ubiquitous in nature, and may be a causative agent in severe, life-threatening infections. In >60% of cases, β-lactam antibiotics are used in the therapy of P. aeruginosa infections, therefore the emergence of carbapenem-resistant P. aeruginosa (CRPA) is a significant clinical concern. In this study, phenotypic methods were used to characterize fifty-four (n = 54) P. aeruginosa isolates, which were included based on their suspected non-susceptibility to meropenem. Minimum inhibitory concentrations (MICs) of meropenem, ceftazidime, cefepime, ciprofloxacin, gentamicin, were determined using E-tests, while colistin MICs were determined using broth microdilution. The isolates were subjected to the modified Hodge test (MHT), the modified carbapenem-inactivation method (mCIM) and the imipenem/EDTA combined disk test (CDT). AmpC and efflux pump overexpression was studied using agar plates containing cloxacillin and phenylalanine-arginine β-naphthylamide (PAβN), respectively. Assessment of biofilm-formation was carried out using the crystal violet tube-adherence method. 38.9% of the strains showed meropenem MICs in the resistant range (>8 mg/L). Efflux-pump overexpression and AmpC-hyperproduction was seen in 44.4% and 35.2% of isolates, respectively. 88.8% of the isolates were characterized as strong biofilm-producers. On the other hand, the presence of carbapenemases was suspected in a minority (16.7%) of tested isolates. As safe and effective therapeutic options in carbapenem-resistant Gram-negative infections are severely limited, characterization of these isolates using phenotypic and molecular-based methods is important to provide insights into the epidemiological features of these pathogens.

Perturbation of the mucosa-associated anaerobic gut microbiota in streptozotocin-induced diabetic rats

Our aim was to map the gut region-specific differences of the mucosa-associated microbiome distribution in a streptozotocin-induced diabetic rat model. Tissue samples from the duodenum, ileum and colon were collected 10 weeks after the onset of hyperglycaemia to analyse the mucosa-associated microbiota using next-generation DNA sequencing. Striking differences were observed in the mucosa-associated microbiota of the duodenum between diabetic and control rats. A significant invasion of the aerobic genus Mycoplasma was apparent in diabetes, and the abundance of the anaerobic phylum Firmicutes decreased massively. It is noteworthy that insulin treatment eliminated the Mycoplasma invasion in the duodenum and apparently restored the anaerobic environment in the mucosa. In the ileum the abundance of the phylum Firmicutes increased in the diabetic samples. Although the proportion of the phylum Proteobacteria decreased moderately, its composition changed significantly, and insulin treatment induced only minor alterations. In the diabetic samples of colon, the abundance of the phylum Firmicutes decreased slightly, the relative number of the bacteria in the phylum Bacteroidetes increased strongly as compared to the control values, and after insulin treatment this increase was more significant. Chronic hyperglycaemia has the most prominent effect on the mucosa-associated microbiota in the duodenum.

A comparative study on Acorus calamus (Acoraceae) micropropagation and selection of suitable population for cultivation in Iran

In addition to various medicinal properties, Acorus calamus (sweet flag) is used in health, food, and perfume industries. Since this species is a rare plant in Iran, its propagation and cultivation are of the great importance. The aim of this study was to investigate the effects of different plant growth regulators on micropropaga-tion of this plant and to select the appropriate population. The root, the rhizome and the leaf explants of three populations (Arzefon, Pelesk, and Alandan) were cultured on MS medium supplemented with different concentrations of α-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP) for callus induction and plant regeneration. The results showed that only rhizome explant resulted in direct plant regeneration. Among different treatments, the 1 mg/l treatment of BAP and NAA - with the highest mean number of regenerated plants (3.75 ± 0.85), the highest percentage of grown explants (91.6%) and maximum average length of regenerated plants (12.06 ± 0.32 cm) - was the best treatment for regeneration of sweet flag. The highest mean number of root (6.6 ± 0.1) was observed in Alandan population in 1 mg/l treatment of indole-3-butyric acid (IBA). According to the present study, Alandan population is suitable for cultivation purposes in Iran.

PhD Abstracts

Abstracts of the Annual Conference of Doctoral School of Biology, University of Szeged – 2021.

A purified lectin with larvicidal activity from a woodland mushroom, Agaricus semotus Fr.

This study investigated the larvicidal activity on Culex quinquefasciatus of lectin purified from fresh fruiting bodies of woodland mushroom, Agaricus semotus. A. semotus lectin (ASL) was purified via ion-exchange chromatography on DEAE-cellulose A-25 and size exclusion chromatography on Sephadex G-100 matrix. Molecular weight (16.6 kDa) was estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The effects of temperature, pH, metal chelation- and larvicidal activity of ASL were also investigated. The ASL indifferently agglutinated the erythrocytes of the human ABO blood system and was stable at acidic pH and below 50 °C whereas 66% of its activity was lost at 60 °C with complete inactivation at 70 °C. ASL is a metalloprotein requiring barium ion as chelation of metals by 50 mM EDTA rendered the lectin inactive, while the addition of BaCl2, among other metal salts, restored the activity. ASL showed larvicidal activity against C. quinquefasciatus larvae after 24 h with a mortality of 5 and 95% at 5 and 25 mg/mL respectively, and LC50 of 13.80 mg/mL. This study concluded that purified A. semotus lectin showed impressive larvicidal activity, which could be exploited in its development as an insecticidal agent.