22 research outputs found
Effect of drought stress on yield, proline and chlorophyll contents in three chickpea cultivars
Drought stress is one of the major abiotic stresses in agriculture worldwide. This study was carried out to investigate the effect of drought stress on proline content, chlorophyll content, photosynthesis and transpiration, stomatal conductance and yield characteristics in three varieties of chickpea (drought tolerant Bivaniej and ILC482 and drought sensitive Pirouz). A field experiment with four irrigation regimes was carried out in a randomized complete block design with three replications. Treatments included control (no drought),drought stress imposed during the vegetative phase, drought stress imposed during anthesis and drought stress during the vegetative phase and during anthesis. All physiological parameters were affected by drought stress. Drought stress imposed during vegetative growth or anthesis significantly decreased chlorophyll a, chlorophyll b and total chlorophyll content. Proline accumulation was higher in ‘ILC482’ than in ‘Pirouz’ both under control and drought stress conditions. Photosynthesis, transpiration, stomatal conductance and yield were higher but sub-stomatal CO2 concentration was lower under drought stress conditions than under control conditions. The results showed that mesophyll resistance is the basic determinate of rate of phototosynthesis under drought stress conditions. Under drought conditions the drought tolerant variety ‘Bivaniej’ gave the highest yield whereas the drought sensitive variety ‘Pirouz’ gave the lowest yield. Drought stress at anthesis phase reduced seed yield more severe than that on vegetative stag
Effect of drought stress and subsequent recovery on protein, carbohydrate contents, catalase and peroxidase activities in three chickpea (Cicer arietinum) cultivars
Drought stress is one of the major abiotic stresses in agriculture worldwide. This study was carried out to investigate the effects of drought stress and subsequent recovery on protein, carbohydrate content, catalase (CAT), and peroxidase (POX) activities in three varieties of chickpea (drought tolerant Bivaniej and ILC482 and drought sensitive Pirouz). A field experiment with four irrigation regimes was carried out in a randomized complete block design with three replications. Treatments included control (well-watering), drought stress imposed during the vegetative phase, drought stress imposed during anthesis and drought stress during the vegetative phase and anthesis. Drought stress imposed during vegetative growth or anthesis significantly decreased soluble protein content and increased water soluble carbohydrate concentration. The tolerant variety accumulated more soluble carbohydrate than the sensitive one. Drought stress at flowering stage had significantly higher POX activity compared to than that at vegetative stage. Compared with the stress, there was significantly more soluble protein after exposure to recovery conditions but POX decreased in all three varieties. These results suggest that CAT and POX activities play an essential protective role against drought stress in chickpea. Antioxidants act as a major defense against radical mediated toxicity by protecting the damages caused by free radicals. An increase was observed in POX and CAT activity of three cultivars under stress conditions throughout the experiment. Results showed that POX acts as the major antioxidant enzyme in chickpea leaves under oxidative stress condition. So activity of this enzyme in stress condition can be used as an index for chickpea cultivars tolerance assessment
Evaluation of the Allergenicity Potential of TcPR-10 Protein from Theobroma cacao
Background: The pathogenesis related protein PR10 (TcPR-10), obtained from the Theobroma cacao-Moniliophthora perniciosa interaction library, presents antifungal activity against M. perniciosa and acts in vitro as a ribonuclease. However, despite its biotechnological potential, the TcPR-10 has the P-loop motif similar to those of some allergenic proteins such as Bet v 1 (Betula verrucosa) and Pru av 1 (Prunus avium). The insertion of mutations in this motif can produce proteins with reduced allergenic power. The objective of the present work was to evaluate the allergenic potential of the wild type and mutant recombinant TcPR-10 using bioinformatics tools and immunological assays. Methodology/Principal Findings: Mutant substitutions (T10P, I30V, H45S) were inserted in the TcPR-10 gene by sitedirected mutagenesis, cloned into pET28a and expressed in Escherichia coli BL21(DE3) cells. Changes in molecular surface caused by the mutant substitutions was evaluated by comparative protein modeling using the three-dimensional structure of the major cherry allergen, Pru av 1 as a template. The immunological assays were carried out in 8-12 week old female BALB/c mice. The mice were sensitized with the proteins (wild type and mutants) via subcutaneous and challenged intranasal for induction of allergic airway inflammation. Conclusions/Significance: We showed that the wild TcPR-10 protein has allergenic potential, whereas the insertion of mutations produced proteins with reduced capacity of IgE production and cellular infiltration in the lungs. On the other hand, in vitro assays show that the TcPR-10 mutants still present antifungal and ribonuclease activity against M. perniciosa RNA. In conclusion, the mutant proteins present less allergenic potential than the wild TcPR-10, without the loss of interesting biotechnological properties. (Résumé d'auteur
Four plant defensins from an indigenous South African Brassicaceae species display divergent activities against two test pathogens despite high sequence similarity in the encoding genes
<p>Abstract</p> <p>Background</p> <p>Plant defensins are an important component of the innate defence system of plants where they form protective antimicrobial barriers between tissue types of plant organs as well as around seeds. These peptides also have other activities that are important for agricultural applications as well as the medical sector. Amongst the numerous plant peptides isolated from a variety of plant species, a significant number of promising defensins have been isolated from Brassicaceae species. Here we report on the isolation and characterization of four defensins from <it>Heliophila coronopifolia</it>, a native South African Brassicaceae species.</p> <p>Results</p> <p>Four defensin genes (<it>Hc-AFP1</it>-<it>4) </it>were isolated with a homology based PCR strategy. Analysis of the deduced amino acid sequences showed that the peptides were 72% similar and grouped closest to defensins isolated from other Brassicaceae species. The Hc-AFP1 and 3 peptides shared high homology (94%) and formed a unique grouping in the Brassicaceae defensins, whereas Hc-AFP2 and 4 formed a second homology grouping with defensins from <it>Arabidopsis </it>and <it>Raphanus</it>. Homology modelling showed that the few amino acids that differed between the four peptides had an effect on the surface properties of the defensins, specifically in the alpha-helix and the loop connecting the second and third beta-strands. These areas are implicated in determining differential activities of defensins. Comparing the activities after recombinant production of the peptides, Hc-AFP2 and 4 had IC<sub>50 </sub>values of 5-20 μg ml<sup>-1 </sup>against two test pathogens, whereas Hc-AFP1 and 3 were less active. The activity against <it>Botrytis cinerea </it>was associated with membrane permeabilization, hyper-branching, biomass reduction and even lytic activity. In contrast, only Hc-AFP2 and 4 caused membrane permeabilization and severe hyper-branching against the wilting pathogen <it>Fusarium solani</it>, while Hc-AFP1 and 3 had a mild morphogenetic effect on the fungus, without any indication of membrane activity. The peptides have a tissue-specific expression pattern since differential gene expression was observed in the native host. <it>Hc-AFP1 </it>and <it>3 </it>expressed in mature leaves, stems and flowers, whereas <it>Hc-AFP2 </it>and <it>4 </it>exclusively expressed in seedpods and seeds.</p> <p>Conclusions</p> <p>Two novel Brassicaceae defensin sequences were isolated amongst a group of four defensin encoding genes from the indigenous South African plant <it>H. coronopifolia</it>. All four peptides were active against two test pathogens, but displayed differential activities and modes of action. The expression patterns of the peptide encoding genes suggest a role in protecting either vegetative or reproductive structures in the native host against pathogen attack, or roles in unknown developmental and physiological processes in these tissues, as was shown with other defensins.</p
Gender-based differences in risk-taking behaviors among high school students in Southeast Iran
Risk-taking behaviors among adolescents can negatively affect different dimensions of their health. This study was conducted to identify the gender-based differences in risk-taking behaviors among high school students in a Muslim population. Grade 10 students studying in high schools located in Kerman Province, Iran were enrolled through cluster sampling (n=2,676), and data were collected using a well-validated questionnaire about violence, sexual behaviors, and traffic-related conduct over the past 12 months. The tool also consisted questions regarding drug use over the past 30 days and over lifetime (i. e., current and ever use of drugs, respectively) The number of female participants was 1,407 (52.6). The boys who had girlfriends (33.0) were almost twice as many as the girls who had boyfriends (17.1). Among the respondents, 27.8 and 12.0 of the boys and girls engaged in physical fighting, respectively. Overall, the prevalence of water pipe use in the last 30 days (18.7) and over lifetime (43.5) was higher than that of the consumption of other substances. The second and third most popular substances used in the past 30 days among boys and girls were alcohol and cigarettes and cigarettes and alcohol, respectively. On the whole, marijuana figured in the lowest lifetime use among the respondents. The rate of risk-taking behaviors in female students was lower than in males, and this difference was more evident than in Western countries. This discrepancy seems to be more obvious in cases where the religious prohibition of a behavior is greater such as extramarital intimacy. © 202
�Students in public and private schools�which are at higher risk of drug use?�: a survey from Iran
Background: Recent evidence from Western countries suggests that private school students are more prone to drug use. Such an evidence is lacking in Muslim countries. The aim of this study was to examine whether the risk of drug use is higher in private schools than public schools. Methods: This cross sectional study was conducted on 650 tenth grade students of Kerman city, the center of largest province of Iran using cluster sampling. Well-validated questionnaires regarding current, lifetime substance use, and perceived use by classmates were utilized. Substances included in the questionnaire were waterpipe, cigarette, alcohol, marijuana, opium, methamphetamine, and Naas. Drug Use Tendency Scale was used to measure the attitudes of students towards drug use. Results: The response rate was 93.7. More than 82 of sample were public school students (n = 504). Current use of cigarette and marijuana was higher in private schools (12.2 and 3.0, respectively) than public schools (4.4 and 0.5, respectively) (P < 0.05). Perceived prevalence of cigarette smoking by classmates was higher among private school students. Conclusion: Despite the popular belief that private schools are better than public schools regarding the risk of substance use, students who attend private schools may be at a higher risk of turning to some drugs comparing to public schools in Iran. © 2020, The Author(s)
Is inclusion of a dummy drug necessary for estimating perceived prevalence of substance use by classmates?
Universal school-based intervention for increasing resilience, and its effect on substance use
Introduction: Universal interventions for preventing substance use are important priorities for schools. The present study aimed to evaluate the effect of a school-based educational intervention on the prevention or reduction of substance use among high school students. Methods: This quasi-experimental study was conducted on 608 grade 10 high school students in Kerman, Iran. The intervention group consisted of 310 students (134 females and 176 males) and their parents, and the control group consisted of 298 students (120 females and 178 males). Students were recruited from September 2018 to February 2019 using a multistage sampling method. The Connor-Davidson Resilience Scale (CD-RIS) and a drug use tendency tool were the instruments used to measure the effect of the intervention. The universal educational intervention, which was based on life skills training, was performed by an experienced clinical psychologist over eleven sessions for students and five sessions for their parents. The postintervention evaluation was performed 3 months later. Results: The intervention decreased students� drug use tendency (p 0.05). Conclusion: The universal resilience-enhancing secondary school-based educational intervention had no protective effect against substance use among Iranian adolescents. This finding may warrant future investigation of primary school students. © 2020 Elsevier Lt
The Perspective of Psychosocial Support a Decade after Bam Earthquake. Achievements and Challenges.
The 2003 Bam earthquake was one of the most catastrophic disasters to have struck Iran. This article summarizes the short-term and long-term psychological, social, and economic impacts of the Bam earthquake on survivors across a decade since its occurrence. Identification and definition of capability as well as recognizing the nature and extent of personal and social capabilities in a community are priceless in preventing disasters and reducing their consequent destruction. © 2013 Elsevier Inc
The effects of group reality therapy on general health among nursing and midwifery students
Background: Nursing and midwifery students experience high levels of stress, particularly during their clinical education. High levels of stress negatively affect general health. Reality therapy (RT) is a method with potential effects on stress. Objectives: The aim of this study was to evaluate the effects of group RT on general health among nursing and midwifery students. Methods: This quasi-experimental study was conducted in Autumn 2015 using a pretest-posttest design. Forty-six students were randomly allocated to an intervention (n = 23) and a control (n = 23) group. Participants in the intervention group received group RT in eight weekly sessions. The General Health Questionnaire was used for general health assessment both before and 1 month after the study intervention. The paired and the independent samples t-test and the Chi-square test were used for the data analysis. Results: There was no significant difference between the intervention and the control groups respecting the pretest mean score of general health (33.05 ± 14.91 vs. 30.34 ± 14.32; P = 0.528). However, the posttest mean score of general health in the intervention group was statistically significantly less than the control group (19.08 ± 10.27 vs. 29.39 ± 12.38; P = 0.004). Conclusion: Group RT can significantly improve general health among nursing and midwifery students. © 2020 Wolters Kluwer Medknow Publications. All rights reserved