IRANIAN JOURNAL OF BIOLOGY
Year:2010 | Volume:23 | Issue:1|Papers Count:20

The genus Ranunculus L. is the largest genus in Ranunculaceae family. This genus has a wide distribution in the world especially in temperate zone. In this study the pollen grains were examined by light microscope and polar axis (P), equatorial axis (E) and the P/E ratio were measured. Also they were studied by scanning electron microscope and the general shape in polar and equatorial view and exine sculpturing of pollen grains were determined. In present study pollen grains of annual species and three groups of perennial species, Radix rhizomatosa, Radix praemorsa and Radix grumosa were studied. It was found that the underground system character is an artificial and unappropriate trait in separating group. Thus as the groups Rhizomatosa and Praemorsa have various pollen and morphological similarities, they can be merged together.

The aim of this study was to determine stand structure and biodiversity of plant species in the Box tree site, Anjilbon. Sampling procedure was the systematic- random method. Type of woody species and their diameter of breast height (DBH ³ 2 cm) were identified and measured and also herbaceous species identified and their numbers recorded within each sampling plot. In addition, number of seedling and sapling of Box tree were recorded. Data analysis was carried out using diversity indices of Simpson, Hill’s N2, Shannon- Wiener, Mc Arthur’s N1 and Wilson and Smith’s evenness index. Species Importance Value (SIV) was calculated in the woody and herbaceous layers. The results indicated that mean richness of woody and herbaceous species were 13 and 21, respectively. In the woody species layer, mean of richness and the mentioned diversity and evenness indices were 3.857, 0.610, 2.852, 1.603, 3.174 and 0.711, and also in the herbaceous layer the mentioned parameters were 2.250, 0.559, 2.582, 1.480, 2.998 and 0.593, respectively. Structurally, mean of diameter and height of Box tree were 5.37 cm and 5 m, respectively, mean basal area equal to 3547.03 cm2, number of Box tree (DBH ³ 2 cm) equal to 3060 per hectare and (DBH<2 cm) were obtained 2523 per hectare, respectively. In the woody species layer, the highest value of SIV belonged to Buxus hyrcana (186.87 %) and the lowest value belonged to Albizia julibrissin (3.03 %), in the herbaceous layer the highest value of SIV belonged to Smilax excelsa (74.82 %) and the lowest values were in Viscum album and Arum sp. (2.94%).

Basil (Ocimum basilicum), a member of a Lamiaceae family, is used in traditional Iranian medicine. Essential oils of basil leaves are composed of phenylpropanoids which are important in treatment of headaches, diarrhea, coughs, warts, worms and kidney malfunctions. Eugenol O-methyl transferase (EOMT) is a key enzyme in phenylpropanoid pathway. It catalyzes the methylation of eugenol, to produce methyleugenol which is original phenylpropanoid compounds in basil. In this research, the level of phenylpropanoid compounds and the expression level of EOMT gene was investigated at different growth stages. The plants cultivated and harvested by hand at 5 growth steps including seedling, with 10 and 50 leaves plants, preflowring and flowering stages. Phenylpropanoid compounds were identified by Gas chromatography/Mass spectrometry (GC/MS) and the level of gene expression was monitored by Semi quantitative RT-PCR. Our results showed that plant growth and maturity both affecte on EOMT gene experession and phenolic contents. The changes observed in phenylpropanoids compound can be as a result of different levels of EOMT gene expression at different growth stage.

Embryological characteristics of Tripleurospermum disciforme were studied in this research. The flowers and buds in different developmental stages were removed, fixed in FAA70, stored in 70% ethanol, embedded in paraffin and sectioned at 7-10 μm with a microtome. Staining was carried out with PAS and contrasted with Hematoxylin. Results indicated that anthers are tetrasporangiate and anther tapetum is of the secretory type. Pollen tetrads are tetrahedral and tetragonal. Pollen grains are 2-celled when shed. Ovule is anatropous, unitegumic and tenuinucellate. Endothelium is uniseriate. Embryo sac development is of the Polygonum type. Antipodal cells increase up to 6-8 and their nuclei become polyploidy. Results of this research showed that embryogenesis of Tripleurospermum disciforme should be regarded as exceptional type. There are two type of embryogenesis. In some florets, that are hermaphroditic, embryo sac was developed as Polygonum type with increasing of antipodal cells and zygotic embryogenesis are in current. But in some florets, that are also hermaphroditic, antipodal cells were increased and they are large in size with condense cytoplasm. They are long-lived and cause to form embryo without fertilization. In these cases the egg apparatus were degenerated due to underutilization of oospher.

Parishan Wetland, a permanent freshwater lake that feds by springs and seasonal streams, is located at a distance of 12 km to the Kazeroon in Fars province. In the present work, a floristic study in the Parishan Wetland and its surroundings was carried out. According to the results, in study area about 269 species belonging to 204 genera and 68 families have been recognized. The largest family of the region is Asteraceae with 40 species. Poaceae with 24, Papilonaceae with 20 and Brassicaceae with 17 species are in the next order. Convolvulus with 6 species is the largest genus among the existing genera, while Centaurea, Euphorbia and Plantago with 3 species, and Amaranthus and Anthemis with 3 species are in the next order. Most of the identified species, i.e.124 species (461%) belong to Irano-Turanian region. Therophytes with 59.1% are the most frequent life form in the Parishan Wetland.

Shastadaisy are from composite family and it is as a part of ornamental flowers of spring and summer would plant in green spaces of cities and consumers’. Shastadaisy has capitule inflorescence the present research aims to study and review its genesis and comparison definition of ray and disk flowers. It can be suitable pattern for several species of capitule inflorescence, floral buds of shadtadaisy flowers, different phases of originating, creation of after primitive studies with stereomicroscope, fixation with FAA. More observation of inflorescence and floret has been done by SEM microscopy. Results showed that procreative meristem, dimension of meristem and its dyeability are increased and meristem during originating to the floret morphological alternation from convex shape in to the flat one and then become dented at the location of central florets which can be raised from more rapid growth of marginal florets, their shape found, pressure in to the central floret meristem. This portioning can be resulted the controlling of cells dividing and cell growth in grooved regions and cells division continues in each floret meristim portion. In progress originating phase’s meristem of each bolted floret would start new portioning in margin of the inflorescence and different parts of each floret is included as stripes sepals, 5 stamens and bolted in receptacle part. three types of ray floret are included as hormapherodit-floret, pistil-floret and sterile florets which had been existed in scattered. Pistils have bifurcate stigma, the homogeneous cells’ style, alveolus ovary and inverted ovules, disk florets originating from margine toward center and each meristem portion beginning of its floret parts formation. Pollengrains types are Tri-colporate. Originating of pollengrains in another is in-simultaneously beside one or two cells pollens. The second mitosis division is caused the formation of tri-cells pollens.

Tomato (Lycopersicum esculentum) is moderately tolerate to salinity (1/3ds/m<EC<6/1ds/m) but high salt significantly reduces crop productivity. The ability of plants to tolerante salt is determined by multiple biochemical pathways that facilitate retention and/or acquisition of water and maintain ion homeostasis. Essential pathways include those that lead to synthesis of osmotically active metabolites (ex. proline) and accumulate them especially in the cytoplasm. The other side it has been reported that calcium ameliorate detrimental effects of salinity stress. In order to study the effects of calcium on growth, compatible solutes and mineral nutrients of tomato plants leaves (Lycopersicum esculentum v. Mobile) grown under salt stress, an experiment was arranged as a factorial experiment, based on completely random design with three replicates. The salt levels included NaCl solutions with electrical conductivity, 0, 8, 10, 12 and 14 ds/m. Calcium used as CaCl2 and CaSo4 (5mM). The plants were grown hydropunically in Hogland's solution. After eight weeks shoots were harvested and shoot dry weights, solouble proteins, solouble sugars, proline and mineral nutrients (sodium and potassium) in leaves were measured. The results showed that increasing of salinity (particularly EC=10 ds/m) signifficantly decreased shoot dry weights. Salinity was raised Na+and decreased K+concentration in the leaves. Furthermore salt stress significantly increased soluble proteins, soluble sugars and proline in leaves. Calcium treatment ameliorated growth and these negative effects via reducing Na+uptake, increasing K+uptake and also with exciting synthesis and accumulation of proline. It seems that calcium plays an essential role in alleviating injury of salinity with membrane stability and maintaining membrane permeability. Therefore, it could offer an economical and simple way in ameliorating adverse effects on tomato crop production caused by high salinity.

Display of peptides on the surface of bacteria have many applications in medicine and biotechnology. Bacterial fimbriae including CS3 pili of E. coli are suitable candidates for expression of foreign epitopes on the surface of bacteria. Permissive sites of this protein, with capability to accept foreign peptides without changes and considerable effects on the structure and function of the protein can be used for expression of foreign peptides. In this study, the permissive sites of the CstH subunit of the CS3 pili were predicted at amino acids 66-67, 100-101 and 109-110 of the mature protein using secondary structure prediction procedures, prediction of disulfide bonds, determination of hydropathy of the protein, alignment of the protein sequence with the sequences in the databases, tertiary structure (modeling) and analysis of the resulted modeles for accessible regions. The results of the in-silico studies were in agreement with the previous laboratory works including display of hexahistidine, cystein reach peptide, ST toxin of enterotoxigenic E. coli and an epitope of Rotavirus NSP4 in this system.

Hybridization is one of the traditional breeding programs in aquaculture. When a new hybrid produced, it is essential to evaluate its characteristics. Different characteristics like morphometric and meristic, physiological, karyological and molecular were used to detect hybrids. Molecular methods like microsatellite is one of the most important and pioneering tools for hybrid detection. In this research, the possibility of microsatellite markers to evaluate hybridization between two important salmonid fish, female rainbow trout Oncorhynchus mykiss and the male Caspian salmon Salmo trutta caspius was tested. Microsatellite primers, Str151INRA, Str73INRA, Str85INRA, Str543INRA, Str591INRA, Strutta58, Strutta12, Ssa197, Ssa171 and OmyFgt1TUF were selected and parents genotype in single pair mating manner (for 3 pairs of fish) were analyzed through PCR. Ssa197 and Ssa171 did not have any junction site on the genome. The others (except OmyFgt1TUF) did not show polymorphism between brood fish and/or produce at least one common band between male and female, so it was impossible to use them as marker for hybrid detection. OmyFgt1TUF showed remarkable polymorphism and clear specific bands between brood fish; the progenies had complete heritage of specific bands of two parents confirming that crossing between female rainbow trout and the male Caspian salmon produce real hybrids. This research showed the possibility of using microsatellite markers to detect hybridization between two species of commercial Iranian salmonids.

Nitrate is one of the most important inorganic nitrogen sources for many plants. Many physiological investigations have led to the conclusion that plants have developed at least two nitrate uptake systems including low- and high-affinity transporter systems to cope with large variations in nitrate concentrations in soils. Molecular studies revealed gene family of NRT2 encode nitrate transporters involved in high-affinity transport systems (HATS). Based on strong correlation between NRT2.1 expression and HATS activity in Arabidopsis thaliana has been proposed AtNRT2.1 has a key role in nitrate uptake by HATS. Among the other AtNRT2 genes, AtNRT2.4 and AtNRT2.5 genes have been fallowed similar expression pattern but their function remains to be revealed. For better understanding of the role of AtNRT2.4 gene in nitrate uptake, A. thaliana wild type genotype and T-DNA mutant affected in the expression of this gene were cultivated on the sand with complete nutrient solution containing 10 mM nitrate for 35 days. Plants were subsequently starved for nitrogen and harvested 0, 10 and 17 days after N-starvation. The effect of AtNRT2.4 gene deregulation on biomass, nitrate and amino acid content and the expression of AtNRT2.1 and AtNRT2 genes was studied. For each two genotypes, shoot/root ratio and nitrate content displayed a decreasing pattern with N- starvation time. These conditions reduced plant total N%. Quantity of total amino acids showed a drastically increased level 10 days after N-starvation. Quantitative PCR analysis illustrated that starved N-conditions up-regulate the expression of AtNRT2.4 gene, while, down-regulate the expression of AtNRT2.1 gene. Results showed that apparently, 10 days N-starvation should be critical point to induce nitrate deficiency signaling pathways. Moreover, it seems that AtNRT2.4 gene has important role in this signal pathway.

Coagulase negative, methicillin resistant Staphylococci specifically Staphylococcus epidermidis are important causes of nosocomial infections. In addition, most of these isolates show multi-resistance to a number of other antibiotics including b-lactams. In this study, methicillin resistance phenotype was compared to the presence of methicillin resistance gene (mecA gene) among the isolates. Fifty five clinical isolates collected from 3 hospitals in Tehran were tested for antibiotic susceptibility using disc diffusion and minimal inhibitory concentrations (MIC) were measured for meticillin using the broth microdilution assay. Presence of the mecA gene in the clinical isolates was detected using specific primers and PCR. The disk susceptibility results showed that 50isolates (90.9 %) including 8 strains with intermediate inhibition zones were resistant to methicillin. MIC results showed 78.1 % methicillin resistance with MIC values ³4 mg/ml. MIC results for the intermediately resistant isolates revealed 5 sensitive and 3 resistant strains. PCR results showed that all methicillin resistant isolates determined by disc diffusion and MIC assays carried the mecA gene except one isolate. Surprisingly, 4 isolates with methicillin sensitive phenotype contained the mecA gene as well. The results of this study suggest that presence of the mecA gene does not necessarily account for methicillin resistance. Ultimately, gene expression which is controlled by the environment, would determine the outcome.

Leaf and stripe rust known as destructive disease of wheat word wide. One of the strategies to control these diseases is employing slow rusting gene which confers resistance in long period, different climate and against various fungi races. Through slow rusting genes have been introduced yet, Yr18/Lr34 is the most important locus because resistance derived is not broken down in most of the wheat growing areas. Indeed, Yr18//Lr34 locus confer resistance at least to six different pathogen including stripe rust, leaf rust, stem rust, powdery mildew, barley yellow dwarf virus as well as spot blotch of wheat. Chitinase belong to defense response cluster and is up-regulated post-inoculation of pathogen in the plant cells. Quantitative real-time PCR has been employed to study the expression profile of Chitinase post-inculcation of leaf and stripe rust at seedling and adult stages. Comparing of Chitinase expression profile against both pathogens has been revealed that the level of expression is increased more in resistant isoline rather than susceptible one at seedling and adult stage. The level of expression was increased 52 times relative to mock inoculation after 3 days of stripe rust inoculation at adult stage, whereas it was only 15 times more in susceptible isoline. Delay in expression of chitinase led to development of fungi mycelium in host cells of susceptible isoline.

Ionizing radiations such as gamma rays have various effects on plant cells. In this study effects of gamma radiation with doses of 60 and 80 Gy on cells from callus of potato (Solanum tuberosum L.) c.v. white desiree were investigated. After irradiation viability of callus cells was revealed by floersine diacetate staining. All irradiated cells with 60 and 80 Gy were viable. Fresh weight and dry weight of irradiated and non irradiated cells were measured. In the irradiated calli, fresh and dry weight increased when compared with non irradiated calli. The total protein of irradiate calli with 60 and 80 Gy decreased in comparison to the non irradiated calli. The DNA damages induced by 60 and 80 Gy of gamma radiation were detected by the comet assay. The results of comet assay indicated that gamma rays with 60 and 80 Gy can induce single and double strand breaks in DNA of potato callus cells.

Paraffin embedded tissue found in archives of the pathology departments are valuable resources of human specimens for molecular studies of diseases such as cancer. However, fixation and parafination steps of tissue damage nucleic acids seriously and give rise to DNA with low quality, which is unsuitable for PCR method. In this research, we investigated some usual methods of extracting and amplifying DNA from paraffin-embedded tissue in order to identify and improve their weaknesses and propose a new combined method. The efficiency of different enzymes including Taq, pfu and pwo polymerases or their mixtures in amplifying DNA extracted from paraffin embedded tissues were also compared. The results shows the efficiency of combined method is higher than previous methods and gives DNA that could be amplified more during PCR reaction.

Mouse P19 embryonic carcinoma (EC) cells are pluripotent and can be differentiated into a population consisting largely of neurons and glia cells using a concentration of 5×10-7 M of retinoic acid (RA). Thus, P19 EC cells are a good model system to study events occurring during the critical phase of neuronal differentiation in vitro. Honey bee venom (BV) from consists of mellitin, phospholipase A2, apamin and several other bioactive substances. Studies have shown that mellitin and phospholipase A2, two major components of BV, play an important role in differentiation of neurons and enhance neurite outgrowth in PC12 cell line. The purpose of this experiment was to examine effects of bee venom and RA on the induction of neuronal differentiation in P19 cell line. The cells were seeded at a density of 3×104 cells/ml in a-MEM containing 2.5% FBS and 7.5% calf serum, and incubated at 37oC in humidified atmosphere containing 5% CO2. Primary results obtained from morphological examination showed that six days after treatment with 5×10-7 M RA, P19 cells produced processes and gradually obtained neuronal phenotype until day 10 of culture and then all cells died on day11. P19 cells treated with 1, 3 mg/ml bee venom produced processes on day 6 and neurons appeared. Then they exceeded to total size until day 10 and produced elongated processes but all cells died on day 11. Using bee venom and RA together had the same but more pronounced differentiating results. It can be concluded that applying bee venom with RA have an additive effect on cell differentiation and proliferation.