Browse

You are looking at 91 - 100 of 5,610 items for :

  • Biology and Life Sciences x
  • All content x
Clear All

The effect of Azospirillum brasilense Sp7 (Sp7) on maize (Zea mays, Mill cv. B73) seedlings was compared when using two common carriers to deliver Sp7 to the seed: phosphate buffered saline (PBS) and magnesium sulfate (MgSO4). Seedling height, leaf chlorophyll levels, and root growth parameters were analyzed with WinRHIZO® at an early vegetative stage of plant development. Scanning and transmission electron microscope (SEM & TEM) analysis showed that carrier components do not effect bacterial binding to plant roots. MgSO4 + Sp7 caused a significant increase in the abundance of thick lateral roots, but stunted plant height, compared to other treatment groups, while relative chlorophyll contents (SPAD) significantly increased in seedlings inoculated with PBS + Sp7, revealing that the two inoculation carriers differentially affect the Sp7-associated plants.

Restricted access
Biologia Futura
Authors: Muhammad Saad, Helen Mary, Umar Amjid, Ghulam Shabir, Kashif Aslam, Shahid Masood Shah and Abdul Rehman Khan

Tartary buckwheat, known for its rich source of health beneficial secondary metabolites, is cultivated in many areas of the world. Among different environmental factors, photoperiod strongly influence its growth, flowering time, and ultimately the yield. In this context, epigenetics could contribute significantly in the regulation of plant response against changing environment. Therefore, with the aim to study the involvement of DNA methylation in photoperiod mediated plant response, genome-wide DNA methylation analysis was performed in two accessions (A1 and A2) of Tartary buckwheat using three photoperiodic treatments, i.e., 10-hr light/day (T1), 12-hr light/day (T2), and 14-hr light/day (T3). Flowering time and plant fresh weight data revealed that accessions A1 and A2 prefer T1 and T2 treatments, respectively. Total DNA methylation ratio increased with the increase in photoperiod in accession A1 but decreased under same conditions in accession A2. Full methylation increased significantly while intensive decrease in hemimethylation was noted from T2 to T3 in A1, whereas full methylation strongly increased and hemimethylation strongly decreased from T1 to T2 in A2. Overall, the DNA methylation events appeared more frequently than demethylation events. This study reports for the first time an accession-/genotype specific pattern of shift in the DNA methylation under different photoperiodic treatments that will pave the way toward identification of specific genes involved in the regulation of plant response against photoperiodic stress.

Restricted access

Treatment of barley grain with gibberellic acid (GA3) during malting promotes abnormal proteolysis and rapid rootlets growth affecting malt quality. This study investigated the potential of ethylene treatment as an alternative by comparing the amylase activity, total starch and total reducing sugars of germinating ‘Puma’ barley seeds treated with ethylene, 1-methylcyclopropane (1-MCP), GA3, daminozide (B-nine), GA3 + 1-MCP, ethylene + B-nine and the control after 24, 48 and 72 h from soaking. Ethylene had no effect on amylase activity. B-nine reduced amylase activity by 16 and 9.6% compared to the control after 48 and 72 h, respectively. The amylase activity of ethylene + B-nine treated seeds was higher (13.3 and 4%) than B-nine treated seeds after 48 and 72 h. This suggest that endogenous GA is important for normal amylase activity and, ethylene stimulates amylase activity where GA synthesis is inhibited. Ethylene and GA3 treatments reduced starch (83.3 mg g−1 and 76.7 mg g−1, respectively) and increased reducing sugars (16.0 and 17.1 µg ml−1, respectively) compared to the control (115.3 mg g−1 starch and 12.1 µg ml−1 reducing sugars) after 72 h. It was concluded that, ethylene may replace GA3 treatment without interfering with starch changing processes during barley malting.

Restricted access
Acta Phytopathologica et Entomologica Hungarica
Authors: S. Kribel, S. Qostal, A. Ouazzani Touhami, K. Selmaoui, A. Mouria, R. Benkirane, El. H. Achbani and A. Douira

Thirty Trichoderma isolates isolated from compost, various crops and soil with roots of adjacent sites to the phosphate mines of Morocco, were tested in vitro for their potential to solubilize phosphorus from phosphate rock. The qualitative assessment of phosphate solubilization by Trichoderma isolates was performed on Modified Pikovskaya Agar (MPA) solid medium. The visual observation of the 3- and 6-day-old cultures did not show any clear zone around the colony. However, all the isolates were able to grow on the culture medium 3 days after incubation, the maximum recorded diameter was 58.6 mm for isolate TR-B 98 (3) and the minimum value was 34.8 mm for isolate TS-EM-98 (2). After 6 days, they showed good radial growth that exceeded 79.8 mm with variable appearance of the mycelial density such as the isolates TS-B 98, TS-EM-98 (1) and TR-CB 2000 (1) that presented, respectively, high, regular and low mycelial density. Also, the Trichoderma isolates produced variable number of conidia on MPA medium. Quantitative estimation on the Modified Pikovskaya Broth (MPB) liquid medium showed a variable potential of the Trichoderma isolates to solubilize phosphate when the amount of soluble phosphorus remained low in the liquid medium without the fungus (0.26 mgL−1). The maximum concentration of soluble phosphorus was 11.92 mgL−1 with percentage of soluble phosphorus equal to 95.39% recorded by the isolate TR-TB 2000 after 9 days of incubation, followed by the isolates TR-B 98 (3), TS-B 98 and TR-EM 2 respectively, 11.20, 10.47 and 9.61 mgL−1 and 89.6, 83.76 and 76.38%. In addition, treatments with Trichoderma isolates provided a lower final broth pH which varied between 6.81 for TOL isolate and 3.40 for TS-B-2000 (2) compared to initial pH (7.2). The isolates that proved potent for phosphate solubilization displayed the highest fresh and dry weights such as TR-TB 2000 (FW = 4.11 g and DW = 2.56 g), while the lowest fresh and dry weight were noted in the weakest isolates for phosphate solubilization such as T27 (FW = 1.025 g and DW = 0.58 g).

The high solubilization potential of Trichoderma isolates can be exploited for the solubilization of fixed phosphorus present in the soil, thus improving soil fertility and plant growth.

Restricted access
Biologia Futura
Authors: Esra Aciman Demirel, Mumin Alper Erdoğan, Bilge Piri Cinar and Oytun Erbas

Introduction

Agomelatine is a potent MT1 and MT2 melatonin receptor agonist and a 5-HT2C serotonin receptor antagonist. The purpose of this study was to show the convulsion-reducing effect of agomelatine, in both clinical and electrophysiological terms, in a pentylenetetrazole (PTZ)-induced experimental epilepsy model in rats.

Methods

The anticonvulsant activity of agomelatine (25 and 50 mg/kg) was evaluated in rat models of PTZ (35 and 70 mg/kg) and compared with the control groups.

Results

Agomelatine administration at doses of 25 and 50 mg/kg resulted in a statistically significant decrease in convulsion scores and time to onset of myoclonic jerks compared to the control groups. In addition, comparison of the two doses employed showed that high-dose agomelatine (50 mg/kg) was significantly more effective than the lower dose. In addition to previous studies, we investigated the anticonvulsant effect of agomelatine using electroencephalogram (EEG). Administration of agomelatine at doses of 25 and 50 mg/kg in PTZ-induced seizures caused a significant decrease in the percentage of peak at EEG.

Discussion

Our results suggest that agomelatine has anticonvulsant activity shown in PTZ-induced seizure model. The results also give some evidences that agomelatine can use on epileptic seizures, but more studies are needed.

Restricted access

Cochliobolus sativus, the causal agent of common root rot (CRR), is a devastating fungal pathogen of barley that can cause significant yield losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, CRR-resistant barley germplasm was developed by crossing three resistant-by-susceptible cultivars currently used in Europe and West Asia. Following greenhouse evaluations of 150 doubled haploid lines derived from these crosses, 40 lines were evaluated under artificial infection conditions using incidence and severity parameters during two consecutive seasons. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to resistant which were consistent in both seasons. However, five promising lines had slightly lower CRR disease than the others. Additionally, significant differences (P <0.05) in mean incidence and severity values were found among lines, with values being consistently higher in the susceptible ones. However, CRR severity increased linearly as incidence increased in both seasons. All together, the present study suggests that, the newly identified resistance lines can serve as potential donors for ongoing CRR resistance breeding program to generate high-yielding commercial barley cultivars, and that the positive correlation between CRR parameters I and S may be beneficial for many types of studies on this disease.

Restricted access
Biologia Futura
Authors: Gaigai Du, Liyuan Wang, Huawei Li, Peng Sun, Jianmin Fu, Yujing Suo, Weijuan Han, Songfeng Diao, Yini Mai and Fangdong Li

Background and aims

Persimmon (Diospyros kaki) is an economically important fruit tree species with complex flowering characteristics. To obtain accurate expression pattern analysis results, it is vital to select a reliable gene for the normalization of real-time quantitative polymerase chain reaction data. The aim of this study was to identify the optimal internal control gene among six candidate genes for gene expression analysis in different persimmon organs and developmental stages.

Materials and methods

This analysis was conducted using geNorm and NormFinder software to show differences in the stability of the six reference genes among tissues and floral developmental stages of the same plant.

Results

Although genes that exhibited moderate expression in NormFinder revealed slightly different expression stabilities than those obtained by geNorm, both sets of results showed that GAPDH was the best reference gene in different organs and floral buds at different developmental stages, whereas 18SrRNA was the least stable gene.

Conclusions

Based on the overall ranking, GAPDH is the most suitable reference gene and is highly recommended for gene expression studies in different organs and different developmental stages of persimmon. This study provides useful reference data for future gene expression studies and will contribute to improving the accuracy of gene expression results in persimmon.

Restricted access

Introduction

Hepatocellular carcinoma (HCC) is found within the first five most common tumors worldwide. Sorafenib is an approved agent in HCC treatment. Sertraline is a selective serotonin reuptake inhibitor. The aim of the study is to investigate the combination of sertraline and sorafenib at hepatocellular cancer cell proliferation and death.

Methods

HepG2 cells were treated with drugs and viability test XTT was performed. Cells were stained with hematoxylin and eosin for histological examination or with anti-Bcl-2 antibody and Hoechst 33258 for immunofluorescence.

Results

Viability results supported dose-dependent antiproliferative effect for both sertraline and sorafenib. Microscopic evaluation of stained cells exerts morphological changes.

Discussion

This is the first study to show that sorafenib and sertraline have synergistic effect in hepatocellular cancer.

Restricted access

Introduction: The study was performed to estimate the prevalence and determinants of occurrence of sexually transmitted infections (STIs) in paratroopers and navy soldiers by anonymously analyzing medical records from the medical departments of two large German barracks in order to assess the need for medical STI prevention.

Methods: Medical records from 80 paratroopers and 80 navy soldiers were screened for records of STI. Results were anonymously collected next to information on risk factors, as well as diagnostic and therapeutic management, and comparatively assessed.

Results: Proportions of suspected STIs were 17.5% and 20%, and proportions of diagnosed STIs were 13.9% and 11.3% for paratroopers and navy soldiers, respectively. Chlamydia trachomatis, human papillomavirus, and genital scabies were observed in paratroopers and navy soldiers, while Gardnerella vaginalis, herpes simplex virus, Molluscum contagiosum virus, Neisseria gonorrhoeae, and Trichomonas vaginalis were additionally identified in navy soldiers.

Conclusions: Although clinical hints for STIs were frequently observed, clinical management was usually restricted to syndrome-based antibiotic treatment without detailed diagnostic workup, leaving room for procedural improvement. Ongoing need for medical STI prevention in the military could be confirmed.

Open access

Bacillus thuringiensis (B.t) is well known for its biocontrol potential against a variety of insects. Nematicidal potential of ten B.t isolates was tested against root-knot nematodes (Meloidogyne javanica (Treub) Chitwood) in vitro, under greenhouse as well as in field conditions. Eggs and second stage juveniles (J2) were exposed to 5 and 25% concentrations of bacterial cell-free aqueous extracts up to 96 h. B.t isolates showed lesser degrees of nematicidal activity at 5% concentration. However, some B.t isolates (B.t-14, B.t-16 and B.t-64) greatly reduced egg hatching and increased J2. All B.t isolates revealed suppressed egg hatching and increased mortality of J2 at 25% concentration. Soil applications with most of the B.t isolates under greenhouse and field conditions significantly improved height and fresh weights of root-knot nematode parasitized okra (Abelmoschus esculentus (L.) Moench). Some isolates, including B.t-64 reduced the number of galls and egg masses. B.t-64 reduced gall formation up to 70% under greenhouse conditions. However, 29% of decrease was observed in field conditions. Similarly, B.t-64 treated plants showed a 56% decreased in eggs/egg mass in a field experiment. Population of root-knot nematodes in the rhizosphere was decreased up to 61% in the field experiment as compared to control.

Restricted access