The Physiological,Biochemical, and Molecular Modifications of Chickpea (Cicer arietinum L.) Seedlings Under Freezing Stress

Journal of Plant Growth Regulation - Fall cultivation of field crops such as chickpea is prone to the risk of freezing stress. It is required to identify the mechanisms through which plants can...     

A rapid protein structure alignment algorithm based on a text modeling technique

Structural alignment of proteins is widely used in various fields of structural biology. In order to further improve the quality of alignment, we describe an algorithm for structural alignment based on text modelling techniques. The technique firstly superimposes secondary structure elements of two proteins and then, models the 3D-structure of the protein in a sequence of alphabets. These sequences are utilized by a step-by-step sequence alignment procedure to align two protein structures. A benchmark test was organized on a set of 200 non-homologous proteins to evaluate the program and compare it to state of the art programs, e.g. CE, SAL, TM-align and 3D-BLAST. On average, the results of all-against-all structure comparison by the program have a competitive accuracy with CE and TM-align where the algorithm has a high running speed like 3D-BLAST.     

Chlorophyll fluorescence parameters and drought tolerance in a mapping population of winter bread wheat in the highlands of Iran

The usefulness of fluorescence parameters as drought tolerance selection criteria for winter bread wheat in the highlands of Iran was studied. A population of 142 recombinant inbred lines, derived from a cross between two common wheat varieties, Azar2 (winter type) and 87Zhong291 (facultative type), was used to analyze the correlation between grain yield and chlorophyll fluorescence parameters at the grain-filling stage under drought stress and supplementary irrigation conditions during 2006–2007 and 2007–2008 seasons at Maragheh experiment station of the Dryland Agricultural Research Institute (DARI) using a RCBD with three replications. The results showed significant differences among the lines in the grain yield and all fluorescence parameters under rainfed and irrigation conditions. The values of chlorophyll content, F ₀, F _m, F _v, F _v/F _m, LWP, YPEC, NPQ, and PI in the drought-tolerant genotypes were significantly higher than those in drought-sensitive genotypes under drought stress. Significant differences were observed between slope coefficients under drought, but not under supplementary irrigation conditions except NPQ (P = 5%). It was concluded that chlorophyll content, F ₀, F _m, F _v, F _v/F _m, LWP, YPEC, NPQ, and PI could be used as additional indicators in screening wheat germplasm for drought tolerance.     

Delta-6 desaturase makes a different fatty acid profile of seed oil in Iranian borage (Echium amoenum Fisch. and Mey.)

Iranian borage (Echium amoenum) from Boraginaceae is a valuable medicinal plant native to Iran and Syria. We determined fatty acid profile and individual fatty acid contents in E. amoenum seed oil using gas chromatography. Nevertheless, the cumulative amount of ω-6 and ω-3 fatty acids in E. amoenum (78.5 %) was in great accordance with those of other species of Echium, Stearidonic acid (SDA, C18:4ω3) and gamma-linolenic acid (GLA, C18:3ω6) constituted only 9.7 % of seed oil in this plant. This observation elucidated the weak activity of delta-6 desaturase (D6DES) in E. amoenum compared with D6DESs of other species. As D6DES enzyme is responsible for converting linoleic acid (LA, C18:2ω6) and alpha-linolenic acid (ALA, C18:3ω3) to GLA and SDA, we isolated coding sequence of D6DES gene and characterized primary structure of the translated protein to probably find some evidences explaining the weak activity of D6DES enzyme in E. amoenum. Gene sequence from E. amoenum showed a high identity of 94–96 % with the other Echium species and the amino acid homology increased by 98 %. All the expected signatures including cytochrome b5 domain and three conserved histidine-rich motifs were found in the translated amino acid sequence. Protein alignment revealed that all the conserved motifs in D6DES sequence from E. amoenum are coincident with its counterparts from other Echium species. However, secondary structure of the enzyme deduced from its primary structure using computational simulation represented obvious differences with D6DES proteins of the other species.     

Evaluation of phenolic and flavonoid compounds in pollen grains of three Citrus species in response to low temperature

Low temperature during the reproductive stage causes sterility of pollen grains and reduces yield. Phenolic compounds function as stress indicators because they accumulate to high levels in many plant tissues in response to a wide range of biotic and abiotic signals. Branches with unopened flowers were collected from trees of three Citrus species (C. reticulata, C. sinensis and C. paradisi) and exposed to different temperatures (5, 10, 15, 20 and 25 °C) for six hours. The highest amount of polyphenol and flavonoids was observed at 5 °C and then their content reduced with increasing temperature in all species. Total phenols and flavonoids content in control temperature as well as all treatments showed that C. paradisi has lower amounts of these compounds than the two other species. HPLC analysis demonstrated that low temperatures, particularly 5 °C, induce flavonoids accumulation as both peak number and flavonoid levels for retention times in pollen grains of all species. The comparison of the HPLC patterns of the three species showed that flavonoid extracts in pollen of C. paradisi decrease in peak number and flavonoids levels for retention times in both control and treatments. Citrus reticulata showed an increase of eight- and two-fold in peaks of one and four, respectively, at 5 °C. Peaks of one and six in C. sinensis increased about four- and three-fold, respectively, at 5 °C compared to the control. In C. paradisi, the levels of peaks two to four were near to the baseline in control samples. With temperature reduction, peak two showed no significant increase but the levels of peaks one, three and four in samples exposed to 5 °C increased approximately three-, three- and four-fold, respectively. ?     

Serum IL-10 involved in morphine tolerance development during adjuvant-induced arthritis

Opioid receptors play an important role in modulation of hyperalgesia in inflamed tissues, but chronic morphine application induces such side effects as tolerance. There is near communications between cytokines and mu opioid receptor expression. This study was aimed to assess the role of serum IL-10 in morphine tolerance development during adjuvant-induced arthritis. Adjuvant arthritis (AA) was induced on day 0 by single injection of Complete Freund’s Adjuvant (CFA) into the rats’ hindpaw. Hyperalgesia, edema, and spinal mu opioid receptor (mOR) variations were assessed on 0, 7, 14, and 21 days of the study. For assessment of the morphine tolerance development, morphine effective dose (4 mg/kg) was administered from the 14th day after CFA injection and continued until the morphine post-dose paw withdrawal latency (PWL); it did not significantly differ from the baseline. For assessment of the effects of IL-10 on tolerance induction, a neutralizing dose (ND50) of anti-IL-10 was administered daily during different stages of the study. AA induction in the right hindpaw of rats resulted in unilateral inflammation and hyperalgesia within 21 days of the study. Anti-IL-10 antibody administration in the AA rats induced marked elevation of hyperalgesia compared to the AA control group. Our data also indicated that morphine effective anti-hyperalgesic dose significantly decreased in the AA rats compared to the control group, which this symptom was aligned with spinal mu opioid receptor (mOR) expression increase during AA. Moreover, there was a significant difference in morphine tolerance induction between the AA and control rats, and our results also demonstrated that IL-10 played an important role in tolerance-induction process. It can be concluded that morphine tolerance slowly progressed when administered morphine effective dose was reduced during AA chronic inflammation. On the other hand, it seems that increased level of serum IL-10 may affect morphine tolerance development during inflammation.     

Use of textile waste water along with liquid NPK fertilizer for production of wheat on saline sodic soils

A field experiment in collaboration with a private textile industry (Noor Fatima Fabrics Private (Ltd.), Faisalabad) was conducted to evaluate the effect of disposed water from bleaching unit, printing unit and end drain for improving growth and yield of wheat under saline sodic soil. Textile waste water along with canal water (control) was applied with and without liquid NPK fertilizer. The application of liquid NPK fertilizer with end drain waste water increased plant height, spike length, flag leaf length, root length, number of tillers (m^?2), number of fertile tillers (m^?2), 1000 grain weight, grain yield, straw yield and biological yield up to 21, 20, 20, 44, 17, 20, 14, 44, 40 and 41%, respectively compared to canal water (control). Similarly, the NPK uptake in grain was increased up to 15, 30 and 28%, respectively by liquid fertilizer treated end drain water as compare to canal water with liquid fertilizer. Moreover, concentration of different heavy metals particularly Cu, Cr, Pb and Cd was decreased in grains by application of waste water along with liquid NPK. The result may imply that waste water application along with liquid-NPK could be a novel approach for improving growth and yield of wheat in saline sodic soils.     

Fluid particle diffusion through high-hematocrit blood flow within a capillary tube

Fluid particle diffusion through blood flow within a capillary tube is an important phenomenon to understand, especially for studies in mass transport in the microcirculation as well as in solving technical issues involved in mixing in biomedical microdevices. In this paper, the spreading of tracer particles through up to 20% hematocrit blood, flowing in a capillary tube, was studied using a confocal micro-PTV system. We tracked hundreds of particles in high-hematocrit blood and measured the radial dispersion coefficient. Results yielded significant enhancement of the particle diffusion, due to a micron-scale flow-field generated by red blood cell motions. By increasing the flow rate, the particle dispersion increased almost linearly under constant hematocrit levels. The particle dispersion also showed near linear dependency on hematocrit up to 20%. A scaling analysis of the results, on the assumption that the tracer trajectories were unbiased random walks, was shown to capture the main features of the results. The dispersion of tracer particles was about 0.7 times that of RBCs. These findings provide good insight into transport phenomena in the microcirculation and in biomedical microdevices.