فهرست مطالب

  • Volume:1 Issue:1, 2015
  • تاریخ انتشار: 1393/12/10
  • تعداد عناوین: 7
|
|
  • Mitra Emam *, Mohammaed Hasan Assare Pages 1-6
    Eucalyptus globulus is an important rapid-growing trees in Eucalypts that applied for agroforestry and tree improvement programs. It has been used as a source of pulp in paper industry, essential oil and honey production. Asexual propagation with conventional methods such as cutting and graft wasnot possible or obtained success was very low, because of hard proliferation of adventitious roots. Then this study was focused on micropropagation of Eucalyptus globulus through mature trees. Apical and axillary buds from adult elite trees in forests of northern Iran were collected in different seasons. The method for sterilization and regeneration was optimized by comparing different combination of plant growth regulators. The highest number of induced axillary shoots was obtained in 0.5 mgl-1 of BA plus 0.5 mgl-1 of Kin after four weeks. Elongated shoots excised at 1.5 cm in length were rooted in 1/4 strenght of macroelements in MS medium with 0.5 mgl-1 of IBA plus 0.5 mgl-1 of NAA and activated charcoal (2.5 gl-1). These plants were transferred in sterile soil at greenhouse condition and successfully established in the field after gradual acclimation.
    Keywords: Micropropagation, Eucalyptus globules, Mature trees, Bud culture
  • Shima Hosseinkhani Hezave, Mehri Askary *, Fariba Amini, Morteza Zahedi Pages 7-18
    Air pollution is the most important environmental problem of last century that threatens the health of living organisms, especially plants. SO2 is one of the main air pollutants that can cause to imbalance in growth and physiological function of plant in high concentrations. Symbiosis of Rhizobium bacteria with alfalfa can cause increasing plant growth and plant resistance to abiotic stresses. In order to study the effects of rhizobia inoculation on alfalfa antioxidants activity and capacity under air SO2 pollution, 35 days plants (noninoculated and inoculated with native or standard Rhizobium meliloti) exposed to the different concentrations of SO2 (0 as a control, 0.5, 1, 1.5 and 2 ppm) for 6 consecutive days (2 hours per day). Results showed inoculation had no significant effect on antioxidants activity and capacity of alfalfa plant. Different concentrations of SO2 pollution had a significant effect on alfalfa antioxidant system. Increasing SO2 stress increased antioxidant activities (I%) and decreased antioxidant capacities (IC50) of alfalfa leaves significantly in comparison to the control plants (under 0 ppm) as well as increased Superoxide dismutase, catalase and Guaiacol peroxidase activity. Inoculation of alfalfa plant with Rhizobium meliloti reduced significantly the negative effects of high concentration of SO2 on antioxidants activity and capacity. In fact, the rate of this change of antioxidant system under SO2 pollution in inoculated plants was lower than in the noninoculated plants. Therefore inoculation with Rhizobium strains could alleviate the effect of SO2 pollution on antioxidant system.
    Keywords: Alfalfa, Antioxidant activity, capacity, Rhizobium, SO2 pollution
  • Sedigheh Kelij *, Ahmad Majd, Ghorbanali Nematzade, Parisa Jonoubi Pages 19-24
    Lignin is one of the major characteristics of plant secondary cell wall that provides structural rigidity for the cells and tissues and hydrophobicity to tracheary elements. Internode tissues of Aeluropus littoralis as a halophyte grass were sampled at different developmental stages (from the first to the fifth internodes ) and under different NaCl concentrations. The influences of NaCl and internode maturity on lignin content and activities of phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD) were investigated. Salt stress induced the activities of PAL and CAD and increased the lignin content. Data indicated that the highest level of PAL activity was found at the first internode and CAD activity in the apical and young parts of stem was higher than the old and basal parts of it. Lignin accumulation correlated positively with PAL and CAD activities under salt stress, but during internodal maturation lignification correlated negatively with PAL and CAD activity. The results suggest that induction of PAL and CAD activities and consequently increasing of lignin deposition at internode tissues can be a strategy for high salinity tolerance in this halophyte.
    Keywords: Phenylalanine ammonia lyase, Cinnamyl alcohol dehydrogenase, salt stress, Development, Aeluropus littoralis
  • Nahid Khosronezhad, Syed Golam Ali Jorsarayi, Abasalt Hosseinzadeh * Pages 25-30
    Reduced sperm quantity and motility are primary causes of infertility in men. Before researchers showed that, Nsun7 gene has roles in sperm motility of mouse, that creation defect in this gene is cause infertility. This gene in human located in chromosome 4, with 12 exons and a hot spot exon (exon7). Our aim is study of the mutations of the exon7 in the normospermic and asthenoteratospermic men. For this, 30 semen samples including fertile and asthenoteratospermic men were collected from IVF center. Semen analysis was performed according to WHO guidelines. A Phenol-chloroform method was used for total DNA extraction from sperm. The exons 7 amplified by forward primer Sun7-F: 5’-GACAAATCTCGAAGTCTTGCTG; and reverse primer Sun7-R: 5’-ACATCCTATTTTTGTGAAAAGGGT. The PCR products direct sequenced and analyzed for mutations. Analyses of PCR direct sequences showed transition mutation (C26232T) in asthenoteratospermic men. This mutation doesn't see in fertile men. We probably that, low semen parameters of the asthenoteratospermic men can be close correlate with these mutations. Thus, analyses of exon 7 direct sequence candidate as a one of diagnosis genetic markers of infertility.
    Keywords: Nsun7, Sperm motility, Mutation, Infertile men, asthenoteratospermic
  • Fereshteh Mir Mohammad * Pages 31-34
    Accumulation of gene changes and chromosomal instability in response to cellular DNA damage lead to cancer. DNA damage induces cell cycle checkpoints pathways. Checkpoints regulate DNA replication and cell cycle progression, chromatin restructuring, and apoptosis. Checkpoint kinase 2 (chk2) is activated in response to DNA lesions. ATM phosphorylate chk2. The activated Chk2 kinase can phosphorylate the substrates, including the Cdc25 phosphatases, p53, PML, E2F-1, and Brca1, which has been associated with DNA repair, cell cycle arrest or induction of apoptosis. Also, Chk2 is a tumor suppressor gene that maintains genomic integrity and it has been suggested as an anticancer therapy target.
    Keywords: Chk2, DNA damage, Cancer cell, Therapy, Apoptosis
  • Mojtaba Mohseni *, Hoda Ebrahimi, Mohammad Javad Chaichi Pages 35-44
    Ethanol producing bacteria are useful in industrial production of biofuel. There are interesting for screening of active bacteria from natural resources and introduce to biofuel industries. The present study aims to isolation of ethanol producing bacteria with characterization, optimization, and evaluation of their ethanol productivity. Samples from various fruits, plant saps and soils were screened for isolation of ethanol producing bacteria then evaluate to find the highest ethanol producer. Of all the 37 ethanol producing isolates, 6 highest producers were selected for characterization. Bacterial growth and ethanol production conditions were optimized based on pH, temperature, agitation, time and initial glucose concentration. Most isolates were occurred single or in pairs. All of isolates were motile and catalase positive but failed to hydrolyze gelatin and produce H2S. Among them, Zym6 was exhibited highest ethanol yield 6.28 gL-1 with optimum pH 6 and growth temperature 35 ˚C. In addition, Zym5 and Zym6 were exhibited highest ethanol yield 19.52 gL-1 and 18.75 gL-1 with xylose and tryptophan, respectively. Thus the optimum condition for ethanol production was a medium composed of pH 6, growth temperature 35 ˚C for 24-48 hours and xylose and tryptophan as carbon and nitrogen sources.
    Keywords: Bacteria, Biofuel: Ethanol, isolation, natural resources
  • Mahsa Razaz, Alireza Naqinezhad *, Arman Mahmoodi, Abasalt Hosseinzadeh, Rouhangiz Abbas Pages 45-54
    Abstract. Natural populations of Carpinus orientalis Mill. Shrub lands occur mainly in high and middle altitudes of the Hyrcanian forests, N. Iran, particularly on steep rocks and forest outcrops. There are some discrepancies on the intra-specific delimitation of this important woody species. The aim of the current study was to examine the anatomical variation of stems and leaves of sixteen populations of Carpinus orientalis collected in four north and northeastern provinces of Iran for the first time. Also this study show that anatomical characters of stem showed the highest correlation to climatic factors include temperature, altitude and precipitation and midrib anatomical characters did not show any relationship.
    Keywords: anatomical characters, Carpinus orientalis, Hyrcanian forest, populations