Phylogenetic relationship and genetic differentiation of Populus caspica and Populus alba using cpDNA and ITS noncoding sequences

Populus caspica Bornm.(section Leuce and subsection Albida), one of the most endangered endemic tree species in the Hyrcanian Forest in Iran, has numerous morphological characteristics that are closely similar to Populus alba; to clarify their taxonomic relatedness and genetic differentiation and thus inform conservation strategies, we used the noncoding regions of chloroplast DNA(cpDNA; trnL-F and trnH-psbA) and the internal transcribed spacer(ITS). Leaf samples were collected from six populations across northern Iran. cpDNA and ITS fragments were amplified by universal primers using the PCR technique and directed sequencing. The results showed that P. caspica is genetically differentiated from P.alba, and two ITS variants were detected within some P.caspica individuals. Conflicts between topologies from ITS and plastid genomes were observed. High differentiation of P. caspica from the other Populus species shown in this study confirmed the diverging taxonomic status of this endangered species. We recommend in situ conservation measures(e.g., protected areas) for at least several populations of this species, especially in the plain regions of the Hyrcanian forest.     

Distribution of the enzyme rhodanese in tissues of the cat (Felis catus)

The enzyme rhodanese (EC 2.8.1.1) is an ubiquitous enzyme which is present in all living organisms, from bacteria to man. It is speculated that this enzyme plays a central role in cyanide detoxification. However, its wide tissue distribution suggests this enzyme might perform other functions beside cyanide detoxification. Although the distribution of rhodanese in different tissues of human and domestic animals has been studied, little is known about the pattern of distribution and physiological roles of this enzyme in the cat. The purpose of this investigation was to determine the enzyme levels and compare the distribution of this enzyme in different tissues of the cat. A selection of tissue samples was assayed for rhodanese activity. The protein content of tissue extracts and enzymatic activities were calculated as units per gram tissue and units per milligram protein of the tissue. Results showed that in terms of units per milligram protein of the tissue (specific activity of the enzyme), colon and rectum mucosal layers and testis were the richest sources of the enzyme followed by ovary, mucosal layer of jejunum and liver. With respect to units/gram tissue, liver followed by testis, colon and rectum mucosal layers, ovary and mucosa of jejunum exhibited highest activities. The results of this study will allow one to speculate on the involvement of rhodanese in several biochemical and physiological functions in different tissues and organs of this species.     

Influence of applied zinc and organic matter on zinc desorption kinetics in calcareous soils

Zinc (Zn) desorption from an exchange complex to solution, the release of Zn from organic matter (OM), crystalline minerals and other precipitates into the solution phase, is the process that controls Zn mobility in soils. An experiment was conducted to determine the pattern of Zn desorption and the soil characteristics affecting it. Desorption of Zn in 15 calcareous soils from southern Iran, treated with 10 mg Zn kg soil^?1 as zinc sulfate (ZnSO₄?7H₂O) and 10 g organic matter (OM) kg^?1 as feedlot cattle manure, equilibrated and extracted with diethylenetriamine pentaacetic acid (DTPA), was studied. Eight kinetic models were evaluated to describe the rate of Zn desorption of soil extracted with DTPA. There was a rapid rate of desorption during the first 4 h followed by a slower rate during the next 12 h. Two-constant rate and simple Elovich models were determined as the best models describing Zn desorption kinetics. Zinc desorption increased as Zn was applied, whereas it decreased with applied OM. The constants of the simple Elovich (β_s) and two-constant rate equations (a and b) were closely correlated with cation-exchange capacity (CEC), OM and pH, which affect Zn solubility, sorption–desorption and diffusion in soils.     

Ameliorative effect of selenium on tomato plants grown under salinity stress

The ability of selenium (Se) to counteract salt inhibitory effects in crop plants, especially in tomato, is still poorly documented. In order to examine the impact of Se addition on the growth, some biochemical parameters related to osmotic adjustment and antioxidant defense of salt-stressed tomato, a two-factorial experiment was conducted in a greenhouse. The plants were supplied with NaCl (0, 25, or 50 mM) and Se (0, 5, or 10 μM), individually or simultaneously. The results showed that salinity had a deleterious impact on plant biomass and physiological parameters studied. The application of Se alleviated this adverse effect by improving the integrity of cell membranes and by increasing leaf relative water content under stress conditions. Moreover, the application of 10 μM Se significantly increased the photosynthetic pigments concentration under salt stress. Salt stress also caused an inhibition of catalase activity, but its activity was restored in the presence of Se. The free radical scavenging activity significantly increased in plants subjected to 25 mM NaCl and supplied with 5 µM Se, compared to NaCl-alone treatment. Both physiological and biochemical results indicate that 10 µM Se treatment can increase plant performance under salt stress, especially under high NaCl concentration.

Abbreviations: CAT: catalase; Chl: chlorophyll; DPPH: 2,2-diphenyl-1-picrylhydrazyl; DW: dry weight; FW: fresh weight; POD: peroxidase; REL: relative electrolyte leakage; RWC: relative water content; free radical scavenging activity (FRSA); TW: turgid weight     

The response of drought-tolerant sugar beet to salinity stress under field and controlled environmental conditions

Abstract

Thirty-four sugar beet drought-tolerant half-sib families were screened in greenhouse experiment under saline (16?dSm^?1) and normal conditions, and a subset of 10 tolerant genotypes were selected for evaluating of yield-related traits, Na⁺, K⁺, and α-amino-N nitrogen contents under saline field condition (12?dSm^?1). Drought-tolerant genotypes showed a different tolerance level under salt stress. Significant correlation was observed between EP2_s and STIEP2 in greenhouse with root yield (RY) in saline field condition. It should be possible that a simple measurement at 16?dSm^?1 in the greenhouse can be used as main part of sugar beet salt-tolerant breeding program. In total, genotypes SBSI-DR I-HSF14-P.23 (# 16) and 436B-HSF9-P.27 (# 26) were recognized as salt- and drought-tolerant genotypes with low Na⁺ and K⁺ contents in root and high white sugar content (WSC) and RY in field. A larger panel of genotypes to validate this kind of association is necessary.     

Effect of water stress and nickel application on yield components and agronomic characteristics of canola grown on two calcareous soils

A greenhouse experiment (5 × 2 × 2 factorial arranged in randomized-complete-design with three replicates) was conducted to assess the combined effects of nickel (Ni) and drought stress on growth and yield parameters of canola (Brassica napus L. var. Talaye) grown on two calcareous soils of loamy and sandy clay textures. Treatments consisted of five Ni levels (0, 0.05, 0.1, 0.5 and 1 mg Ni kg^?1 soil) and two levels of water status 100% and 60% field capacity (FC and 0.6FC, respectively). Growth parameters and yield components of plants decreased at drought-stress conditions. Almost all of the studied growth/yield parameters of canola grown on loamy soil were significantly more than those of the sandy clay soil, probably due to the increased capability of loamy soil for supplying the plant water/nutrient requirements. Nickel could positively affect some of the mean growth and yield parameters (e.g., grain yield) over both of the water status conditions. Nevertheless, some of the traits not only increased by Ni fertilization but also decreased compared to that of the control. The positive responses of canola was observed with higher amounts of applied Ni in the sandy clay soil than in loamy soil, e.g., the maximum grain yields of canola grown on loamy and sandy clay soils were obtained with applications of 0.5 and 1 mg Ni kg^?1, respectively. Generally, results demonstrated that Ni could not mitigate the negative effects of drought stress on canola growth or yield components.     

Quantum dot/polyvinyl alcohol composite nanofibers membrane as highly sensitive fluorescence quenching-based sensors

Nanofibrous membranes are intensively applied to fabricate advanced intelligent devices like highly sensitive sensors due to their flexibility, high porosity, high surface area and good mechanical and chemical stability. In this work, fluorescent cadmium telluride (CdTe) quantum dots (Q.Ds) were synthesized and then uniformly embedded in poly vinyl alcohol (PVA) nanofibers by electrospinning technique to serve as reversible quenching fluorescence-based sensor to detect the traces of benzene, toluene and xylene vapors selectively at room temperature. Fluorescence analysis suggested that Q.Ds preserve their original fluorescent property in solid nanofiber as if they were in solution. Scanning electron microscopy images showed the uniform diameter of nanofibers. In addition, Fluorescence and transmission electron microscopy (TEM) measurements confirmed the uniform distribution of the Q.Ds into nanofibers structures. The main mechanism of quenching based sensor was designated as electron transfer from thiogalycolic acid (TGA) — capped Q.D surface to target volatile organic compounds (VOC’s) vapors. Fabricated sensor showed selectively sensing upon trace of different target vapors due to the difference in the electronegativity of various VOC’s molecules. For example exposure to more electron withdrawing toluene molecules induces severe quenching effect on fluorescence intensity of Q.D (about 25 %) over xylene exposure. Moreover, it was observed that reducing the diameter of nanofibers enhanced the sensitivity of sensor.     

Interaction between LINC-ROR and Stemness State in Gastric Cancer Cells with Helicobacter pylori Infection

Background:LINC-ROR, as a cancer-related lncRNA, has vital roles in stem cell survival, pluripotency, differentiation, and self-renewal in hESCs. However, cancer-related molecular mechanisms, its functional roles, and clinical value of LINC-ROR in GC remain unclear. In this study, we aimed to investigate probable interplay between LINC-ROR with SALL4 stemness regulator and their role with the development of the disease. Methods:The mRNA expression profile of LINC-ROR and SALL4 was assessed in tumoral and adjacent non-cancerous tissues of GC patients, using quantitative real-time PCR. Results:Significant LINC-ROR underexpression and SALL4 overexpression were observed in 55.81% and 75.58% (p < 0.0001) of samples, respectively. The expression of LINC-ROR and SALL4 were significantly correlated with each other (p = 0.044). There was an association between the underexpression of LINC-ROR and sex, stage of tumor progression, tumor type, and location of tumor (p < 0.05), and H. pylori infection with SALL4 expression (p = 0.036). There were also significant correlations between concomitant mRNA expression of SALL4 and LINC-ROR in tumors located at distal noncardiac, positive for H. pylori infection, tumors with invasion into the muscle layer of the stomach, and grade II tumor (p < 0.05). Conclusion:The clinical results of the SALL4-LINC-ROR association propose a probable functional interaction between these markers in tumor maintenance and aggressiveness. Our study can help to understand one of the mechanisms involved in the progression of GC through the function of these regulators. Key Words: LINC-ROR, Non-coding RNA, SALL4     

Identification and Characterization of Metallo-β-Lactamases Producing Pseudomonas aeruginosa Clinical Isolates in University Hospital from Zanjan Province,Iran

Background: Infectious by Pseudomonas aeruginosa has spread worldwide and metallo-beta-lactamases (MBL) are being reported with increasing frequency. The aim of this study was to investigate the antibiotic susceptibility and distribution of bla_VIM and bla_IMP genes in P. aeruginosa isolates from Zanjan Province of Iran. Methods: A total of 70 P. aeruginosa isolates were identified from patients admitted at intensive care units. The antimicrobial susceptibility was tested by disk diffusion (Kirby-Bauer) method and for production of MBL using double-disk synergy test (DDST). After DNA extraction, the presence of bla_VIM and bla_IMP genes and class 1 integron were detected by PCR. RESULTS: Most of the isolates were resistant to meropenem, cefotaxime and imipenem (IPM). Also, 44/70 (62.85%) IPM resistant isolates were confirmed by DDST. Of the 44 clinical isolates, 41 (93%) isolates showed MIC≥4 µg/ml for IPM. Based on the DDST results, 36 (87.8%) were confirmed to be MBL producers. PCR amplification showed that 23/41 (56%) carried bla_VIM and 10/41 (24.3%) possessed bla_IMP gene. Also, 31/44 (70.5%) isolates contained class 1 integron gene. Conclusion: Our results highlight that the genes for Verona integron-encoded metallo-β-lactamase, IPM β-lactamases and class 1 integrons were predominantly present among the IPM-resistant P. aeruginosa tested in our province and also the frequency of bla_VIM type is higher than bla_IMP. This is the first report of P. aeruginosa strains producing bla_IMP with high frequency from Zanjan province of Iran. Key Words: Pseudomonas aeruginosa, Beta-lactamases, PCR