Progress in Biological Sciences
Volume:2 Issue: 2, Summer and Autumn 2012

The genus Astragalus L. (Fabaceae) is reviewed from both phyloenetic and taxonomic points of view. As the largest genus of flowering plants it has attracted many researchers, but much work remains to be done. A short taxonomic history with special focus on infrageneric classification of the genus, a list of phylogenetic studies including the applied markers and sampling strategies as well as a short discussion on evolution of morphological characters are presented.

Spiders are poorly studied in Iran, based on the latest studies the spider fauna of Iran includes 394 species in 126 genera belonging to 36 families. Considering the climatic and geographical variation of Iran, it can be assumed that Iran has a rich spider fauna compared to the adjacent countries. The present study seeks to take a new step in the ongoing active research of Iranian spider fauna. Therefore, the spider fauna of Golestan Province were studied here. The main purpose of this study is to present new data on twenty-five new faunistic records for Golestan Province. According to previous studies 90 spider species were known in Golestan. This study was conducted during a period of two years. Samplings were performed using hand collecting and pitfall traps. As a result, twenty five species were identified as new records for Golestan Province, ten of which are new records for Iran including Araneus marmoreus Clerck, 1757, Cyclosa sierra Simon, 1870, Gibbaranea sp., Singa semiatra L. Koch, 1867, Castianeira arnoldii Charitonov, 1946, Drassyllus praeficus (L. Koch, 1866), Drassodex sp., Alopecosa cf. albofasciata (Brullé, 1832), Metellina cf. mengei (Blackwall, 1870), and Parasteatoda lunata (Clerck, 1757). Furthermore, the family Corinnidae and the genus Castianeira, were recorded for the first time from Iran.

Metal ions are the main impurities of water and media ingredients used in fermentation processes. In this research, the effect of Ca+2, Co+2, Cu+2, Fe+2, Mg+2, Mn+2 and Zn+2 as chloride and sulfate salts was studied on the clavulanic acid production and Streptomyces clavuligerus growth. All chloride salts had negative effect on clavulanic acid production and no clavulanic acid was produced in the media containing more than 1.5 mM ZnCl2 and 18 mM FeCl2. CuCl2 and CaCl2 increased biomass production, while the other chloride salts decreased it. Concentration of clavulanic acid in the 0.2 mM MnSO4 containing medium was 1.21 times more than that of control. There was no significant difference in antibiotic concentration in the medium containing 0.41 mM MgSO4 and control. Other sulfate salts decreased antibiotic production. MgSO4, CuSO4 and FeSO4 increased the biomass, while other sulfate salts decreased it. Minimum and maximum specific consumption rate of glycerol were seen in the medium containing CuSO4, and MnSO4, respectively.

This study was carried out to investigation the possibility of using Triadimefon (TRD) in order to decrease the adverse effects of salt stress on Medicago plant. Triadimefon is a member of Triazol compounds which enhances stress tolerance through physiological processes. Two cultivars of Medicago sitiva including Hamedani and Yazdi were used in this study. Plants were treated with 1, 2 and 4 mg/l TRD and 0, 100 and 140 mM NaCl. Salinity reduced fresh and dry weight of plants in both cultivars with the result of higher reduction in cv. Hamedani significantly. Salt stress also increased proline, MDA and H2O2 contents and also the activity of SOD and P5CS, and the level of P5CS ranscripts, while decreased the activity of CAT and POX in both cultivars. When plants were treated with TRD and NaCl, less proline, MDA and H2O2 accumulation occurred. Interaction of NaCl and TRD increased SOD but reduced P5CS and CAT activity. Both NaCl and TRD treatments increased P5CS transcription in cultivar Yazdi while showed less effect in Hamadani cultivar. Interaction of TRD and NaCl alleviated the negative effects of salt stress on plant growth, especially at 2 mg/l TRD. The results of the present study showed that 2 mg/l TRD was the most effective level to alleviate the negative effects of NaCl treatment on Medicago sativa plants.

MicroRNAs (miRNAs) are short, endogenous non-coding RNAs that function as guide molecules to regulate transcription of their target messenger RNAs. Several methods including low-density qPCR arrays are being increasingly used to profile the expression of these molecules in a variety of different biological conditions. Reliable analysis of expression profiles demands removal of technical variations in data, which is achieved via applying normalization techniques. Most normalization techniques have been developed for mRNA microarrays and new and modified methods should be used or miRNA studies in general and RT-qPCR miRNA arrays in particular, because of low number of miRNAs. Here, we introduce a new method based on Procrustes superimposition of arrays to be normalized on a reference array. To assess the performance of our normalization method, we compared this method to the common miRNA normalization methods. Removal of technical variation was assessed by robust modeling of mean square error (MSE) in different subsets of real miRNA datasets before and after applying normalization. We show that our method outperforms the other normalization methods in concurrent reduction of technical variation and retention of biological variability.

The p21 belongs to the CIP/KIP family of CDK inhibitors involved in cell cycle arrest at specific stages of the cell cycle progression. DNA methylation is the best studied epigenetic mark that have been evidently associated to chromatin condensation, and repression of gene transcription. The CpG island hypermethylation in promoter region of certain genes occurs in cancer cells and affects tumorigenesis. The aim of the current study was to assess DNA methylation pattern of p21 gene promoter region in the MCF7, T47D, MDA-MB-231 and MDA-MB-468 human breast carcinoma cell lines. The methylation status of cancer associated gene, p21waf1/cip1 was analyzed at CpG sites in the promoter region using a sensitive methylation-specific PCR (MSP) technique. The total genomic DNA from each cell line was isolated and subjected to the sodium bisulfite treatment to differentiate between methylated and unmethylated CpG islands. Then MSP was performed using designed primers for methylated (M-MSP) and unmethylated (U-MSP) forms of CpG islands in the promoter region of p21 gene. The results of the MSP indicated that promoter of p21 gene was consistently unmethylated in tested human breast cancer cell lines. Therefore, methylation inactivation of the p21waf1/cip1 does not commonly happen in all cancer cell lines.

Fusarium graminearum is causal agent of economically catastrophic disease of cereal Fusarium Head Blight (FHB) around the world. In addition to causing a loss of yield, this fungus causes serious threats to humans and animals due to the contamination of grain with the trichothecene mycotoxin. TRI101 gene, a Fusarium spp. gene, encodes an enzyme that transfers an acetyl group to the C3 hydroxyl of trichothecenes. We introduced TRI101 gene from F. graminearum to tobacco to test its usefulness for decontamination of mycotoxins. The acetyltransferase activity of this gene was detected in transgenic plants. The growth pattern of T1 seedling was examined at present of deoxynivalenol (DON) and crude extract of mycotoxin. A significant difference in growth rate was seen in plants expressing TRI101 as compared to wild type in DON assay. There was no significant difference in growth rate of the wild type and transgenic plants in presence of a mixture of mycotoxins. According to the results, it seems although FgTRI101 enzyme is suitable for detoxification of DON, more studies are required to evaluate its performance in detoxification of mixture of Fusarium toxins.

Genetic transformation studies were carried out to standardize a protocol for Agrobacterium -mediated genetic transformation of three economically important strawberry (Fragaria x ananassa Duch) cultivars Kurdistan’, Camarosa’, and ‘Paros’. Shoot regeneration frequency 72, 65 and 30% was obtained on MS (1) basal medium supplemented with 2% glucose and 4 mg/l TDZ for Camarosa, Kurdistan and Paros, respectively. To optimize the concentration of kanamycin for these cultivars, we observed the responses of leaf explants to different concentration of kanamycin (0-100 mg/l) in the media. Our results showed that 75 mg/l was an effective concentration of kanamycin. For genetic transformation, Agrobacterium tumefaciens strain C58C1RifR (pGV2260) harbouring the binary vector pTJK136 containing uidA gene with intron along with kanamycin resistance gene (npt-II) was used. After five days pre-incubation and 72 h co-cultivation, transformed cells (explants) were able to grow on the selective regeneration medium containing 75 mg/l kanamycin and 500 mg/l cefotaxime, while, control explants failed to grow. The regenerated putative transgenic shoots were analyzed by histochemical GUS assay and PCR analysis. Transformation efficiency based on inoculated explants number was 2, 1 and 3% for ‘, Camarosa’, ‘Paros ’, and ‘Kurdistan’, respectively. The standardized protocol would be useful for Agrobacterium-mediated genetic transformation of these cultivars with important agronomic genes.

PROSITE database contains a set of entries corresponding to protein families, which are used to identify the family of a protein from its sequence. Although patterns and profiles are developed to be very selective, each may have false positive or negative hits. Considering false positives as items that reduce the selectiveness of a pattern, then, the more selective pattern we have, a more accuracy in protein family detection we will get. In this paper, we have provided a method for improving the PROSITE patterns by reconstructing them in a manner that they not only still match to true positive hits, but also match to less false positive hits. From 973 PROSITE patterns, 283 have been improved by our method. We have applied the provided method on the PROSITE database and the improved resulting database is available at http://cbp.ut.ac.ir/iPROSITE.

Septoria tritici blotch (STB), caused by the ascomycete fungus Mycosphaerella graminicola (asexual stage: Septoria tritici), is one of the most important foliar diseases of wheat. In this research, quantitative expression analysis of five candidate genes for the induction of resistance to STB (PR-1, Bsi, Msr, Per, and Ppi) was conducted in the wheat cultivars ‘Seri 82’ (susceptible) and ‘Frontana’ (resistant). The study used a randomized complete block design with three replications and five time-points (0, 3, 6, 12, and 24hours after inoculation). Evaluation of the expression of five candidate genes by real-time PCR showed that expression of Per, pr-1, Bsi, Msr genes was higher than 5, 3, 3 and 2 fold in treatment vs. control samples in ‘Frontana’ at 12 hours after inoculation respectively. The results indicated the effectiveness of these genes in the conferral of resistance to STB in wheat.

Cyanobacteria are well known for their production of a multitude of highly toxic substances. The genus Stigomena is regarded as good candidates for producing biologically active secondary metabolites, which are highly toxic to humans and other animals. The carcass of a dog was found at the shore of Lake Ali-Abad, Iran. Biomass from the discovery site appeared to be of cyanobacterial nature. We identified the strain as freshwater bloom-forming representative of the Stigomena genus on the basis of its 16S rRNA sequence. It carried the mcyE gene, as well as a potential cryptic hassallidin gene cluster. These results suggest that microcystin-induced liver damage may have significantly ontributed to the death of the dog. This case is thus the first reported incident of potential microcystin intoxication in a dog in Iran.

The rodents’ fauna of boundary zones of Iran are still poorly known. In this research rodents fauna of Khaf township in northeast of Iran have been reported mainly based on pellets of birds of prey. Alive samples and also rodent’s remains from pellet materials of birds of prey in the present study was collected from 46 localities in Khaf, northeast of KhorasanRazavi province and different specimens were collected during the period of April, 2011 until September, 2012. A total of 718 prey bird pellet material and six complete (living) samples were identified based on morphological methods on external anatomy (in complete samples), teeth, cranial and dentary bones (in pellets) and as a result of the study, the rodents fauna of Khaf consists of twelve species belonging to nine genera and three families including; 1) dae (Allactaga elater), 2) Cricetidae (Cricetulus migratorius), 3) Muridae (Tatera indica, Gerbillus nanus, Meriones persicus, Meriones libycus, Meriones crassus, Meriones meridianus, Rhombomys opimus, Mus musculus, Nesokia indica), and also one species of Lagomorpha (Ochotonidae: Ochotona rufescense) and Soricomorpha (Soricidae: Crocidura gmelini).

of high-quality vegetable and industrial oil. 9 RAPD primers, 6 AFLP primer combinations and 12 agro-morphological traits were used to assess the genetic diversity of 20 accessions of saf flower representing global germplasm variability. Jacquards’ similarity coef ficient were used to understanding the genetic relationships among ccessions, for AFLP and RAPD markers and Euclidian similarity coefficient for agromorphological markers. UPGMA clustering algorithm was used for all markers. RAPD and AFLP markers grouped accessions into two main clusters whereas dendrogram of morphology data delineated the accessions into three clusters. Correlation coef ficient comparisons between similarity matrices and co-phenetic matrices obtained with the three markers revealed that AFLP displayed no congruence vis-a-vis RAPD and agromorphological data.

Ornithine is a non-proteinogenic amino acid, which plays an essential role in the metabolism of plants. Regard to the chirality of the molecule, physiological response of the plant cells to its two enantiomers have not been widely investigated yet. In the present study, suspension-cultured tobacco cells were treated with 1 mM of D- and Lenantiomers of ornithine in normal conditions as well as under stress of 50 mM NaCl. Differential effects of L- and D-enanthiomers were observed either in normal or under salinity stress conditions. L-ornithin adversely affected the growth of tobacco cells in normal conditions and its detrimental effect was intensified by salinity. Treatment with D-ornithine however, not only did not change the growth but also alleviated it under salt stress. Physiological response of tobacco cells to D-ornithine in normal conditions was accompanied by increasing of polyamines. Under salinity stress however, D-ornithine treatment increased the activity of major antioxidant enzymes i.e., superoxide dismutase, catalase, and peroxidase and also increased proline content of the cells, all together resulted in lowering H2O2 and maintenance of cells membrane integrity. The results suggested that D-ornithine is a potent compound for activation of anti-oxidant system of plant cells and alleviation of stress condition.

Bioconversion of cellulosic material into bioethanol needs cellulase complex enzymesthat contain endoglucanase, exoglucanase and beta glucosidase. One of the most important organisms that produce cellulases is the filamentous fungi, Trichoderma reesei which able to secrete large amounts of different cellulases. These enzymes are probably the most widely used cellulases industrially, however, the cellulases excreted from fungi are not stable at high pH or high temperatures. In this study methylotrophic yeasts, Pichia pastoris and Hansenula polymorpha were used for the comparative heterologous production of endoglucanase II. Two synthetic egII genes with P. pastoris and H. polymorpha codon preferences were transferred into the yeasts. In addition, both expression vectors contained the pre-pro-sequence of Saccharomyces cerevisiae mating factor alpha to allow secretion of protein. Enzymes characterization demonstrated increasing thermal stability in both recombinants EGII compare with native enzyme from T. reesei and the Hansenula enzyme was more stable than Pichia in higher temperature. Biochemical properties determination on different substrates showed higher binding site affinity in Pichia than Hansenula and native one. We can conclude that P. pastoris and H. polymorpha are appropriate hosts for expression and production of endoglucanase with improved thermal stability.