Ghorban Ali Nematzadeh

Identification and cloning of the Cu/Zn superoxide dismutase gene from halophyte plant Aeluropus littoralis.

Reactive oxygen species (ROS) derived from molecular oxygen under biotic and abiotic stress such as salinity which have deleterious effects on cell metabolism. The toxic effect of ROS counteract by enzymatic as well as non-enzymatic antioxidant system. Superoxide dismutase (SOD) has a potential role for elimination of ROS. Halophytes respond to salt stress at different levels and can be a model for increasing salt tolerance in crop plants. Thus salt tolerance gene isolation and cloning of gene as well as subsequent transformation are first step for sensitive crop improvement. Aeluropus littoralis is a halophyte plant from poaceae family can be as a beneficial plant with high potential for creal breeding. There was no report on isolation of SOD gene from A. littoralis and little genomic study of this plant carried out. In this study a novel gene from A. littoralis isolated. This gene amplified by reverse transcription-PCR and cloned in E. coli pTZ57R/T cloning vector. The AlSOD gene sequence contained 456bp and the deduced transcripts encoding 152 amino acids shared a high homology with those putative CuZnSOD of higher plants like Zea mays and Oryza sativa.

Uptake and translocation of cadmium and nutrients by Aeluropus littoralis

To our knowledge there has been no research on Aeluropus littoralis as a halophyte plant, when grown in soil contaminated with cadmium (Cd). Hence, the ability of A. littoralis to take up Cd and some nutrients was investigated in a pot experiment. Five levels of soil Cd concentration were tested (15, 30, 60, 120 and 240 mg Cd kg−1 soil). Plants were harvested at three different times and analyzed for Cd, N, P, K, Mg, Mn, Cu, Fe and Zn concentrations. Plant biomass decreased as a result of excess Cd. Cadmium concentration in plant shoots increased with increasing Cd supply, significantly affecting the plant nutrient content. An excess Cd supply increased macronutrient and decreased micronutrient concentrations in the plant. Although, the research process will become more complicated, this new approach may help to investigate the tolerance of A. littoralis to Cd stress for use in phytoremediation.

Salinity response pattern and isolation of catalase gene from halophyte plant Aeluropus littoralis

The role of the antioxidant defense system in salt tolerance of Aeluropus littoralis has not been yet reported; therefore in the present study, the changes of catalase (CAT) activity in this halophyte plant was investigated and CAT gene was isolated. The leaves of treated and control plants were harvested at various times, starting 1 day prior to initiating treatment, then periodically at 72-h intervals for 21 days. The data collected showed that CAT activity increased significantly with time in plants treated with 200, 400, and 600 mM NaCl when compared with the control plants. Maximum enzyme activity was observed between the 6th and 12th day at all NaCl concentrations. CAT gene was isolated and cloned via pTZ57R/T cloning vector in Escherichia coli. CAT gene encoded 494 amino acids and had also high homology of 90, 87, 86, and 86% with CAT genes from Zea mays, Oryza sativa, Triticum aestivum, and Hordeumvulgare, respectively.

Glyceraldehyde-3-phosphate Dehydrogenase Gene from Halophyte Aeluropus lagopoides: Identification and Characterization

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which plays an important role in central carbon metabolism, was studied in Aeluropus lagopoides, which is an important perennial grass found in drought-stricken areas and deserts from Africa to South Asia. Aeluropus lagopoides is an ideal candidate plant system to identify novel or enhanced stress tolerance mechanisms. The GAPDH has stable expression under different conditions and it is a typical housekeeping gene in prokaryotes and eukaryotes. So far, there are no reports about identification of housekeeping genes for gene expression analysis in Aeluropus lagopoides. Thus in the present study, a GAPDH cDNA was cloned and sequenced from this plant. Our results revealed that the open reading frame (ORF) (1014 bp) encoded a polypeptide of 337 amino-acid residues. The deduced amino acid sequence indicated a protein with a molecular weight of 364.95 kDa and estimated isoelectric point value of 7.06. Multiple alignments of putative amino acid sequences indicated high similarity between Aeluropus lagopoides GAPDH and analogous protein derived from other plants, particularly monocots. Nucleotide blast and phylogenetic analysis revealed that this plant had maximum identity with Cleistogenes songorica. Results of this experiment can help us do transcriptional analysis by qRT-PCR to identify stress-tolerance mechanisms.

Antioxidant responses of halophyte plant Aeluropus littoralis under long-term salinity stress

Salinity influences the agricultural production all over the world. This constrain, similar to others biotic and abiotic stresses generate the reactive oxygen species such as superoxide, hydrogen peroxide and hydroxyl radicals. In the evolution process of halophyte plants the mechanisms to detoxify ROS, such as antioxidant enzymes, have been developed. Aeluropus littoralis is a special halophyte that selected to our research, so the plants treated with NaCl at different salt concentration (0, 250, 450 and 650 mM) for a period 45 days. Leaves and roots (separately) collected and their proteins extracted for superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) activity assay. Meanwhile the electrolyte leakage of leaves analyzed and increased at 450 and 650 mM of NaCl concentrations. Superoxide dismutase and catalase showed same pattern for changing in enzymatic activities (increasing activity by salt stress in roots and decreasing in shoot at 450 and 650 mM stress), also peroxidase and ascorbate peroxidase activity almost increased in all stress conditions.

Phytochemical, Antioxidant and Biological Activities of the Essential Oil of Astragalus alopecurus Pall. Fruits from Northern Iran

Abstract This research investigates the chemical componds of Astragalus alopecurus Pall. fruits essential oil, and evaluates the antimicrobial effects of fruits on different plant pathogens. The essential oil of Astragalus alopecurus Pall. fruits was analyzed by GC/MS. Antimicrobial effect was examined on 14 microorganisms, containing eight bacteria and six fungi, utilizing disk diffusion and MIC methods. Astragalus alopecurus Pall. fruits were also exposed to screening for feasible antioxidant activity with utilizing 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and guaiacol peroxidas, superoxide dismutase and catalase enzymes. Forty four compositions were recognized representing 94.13% of the total oil; with α-pinene (18.41%), humulene epoxide II (12.84%) and α-humulene (11.81%) being the major ingredients. The essential oil indicated considerable activity on Staphylococcus aureus (MIC = 50 μg/mL) and Pyricularia oryzae (MIC = 12.5 μg/mL). Moreover, the analysis of free radical scavenging activities of the Astragalus alopecurus Pall. fruits indicated antiradical activity of 146.59 μg/mL in DPPH, 3.853 mmol activity/mg protein in guaiacol peroxidase, 1.655 U/mg protein in superoxide dismutase and 28.644 μmole activity/mg protein in catalase. In addition, the phytochemical analysis demonstrated medium to well amounts of phenolic (53.61 mg/g), flavonoid (115.64 mg/g) and alkaloid (0.11 mg/g) compositions in Astragalus alopecurus Pall. fruits. Gained results propose that this plant can applay as a potential source of biocide for inexpensive and environmentally friendly disease control methodes.