مجله سلول و بافت
سال چهارم شماره 2 (تابستان 1392)

Plants produce a big group of secondary metabolites which are used as medicinal compounds. According to recent estimates، global market value of herbal medicines، including medicinal plants and their products، significantly has been increasing. Considering to the fact that most of the world market for medicinal plants، production and supply of secondary metabolites derived from these plants are concerned and the plant secondary metabolites are of high economic value. Chemical synthesis of these metabolites is an expensive process. So production of metabolites by different biotechnological methods such as cell culture is a useful alternative. Molecular recognition and elicitor-plant receptors interaction is a complex process requiring for signal transduction. Biotic elicitors induce secondary metabolites and hypersensitive responses by activation of defense mechanisms. Manipulation of cell culture media by elicitors is an important strategy for inducing secondary metabolism and production of valuable metabolites. Molecular recognition and elicitor-plant receptors interaction is a complex process requiring for signal transduction. Following perception of elicitor signals، rapid defense responses can be organized as follows: increase of ionic currents across the plasma membrane، reactive oxygen species (ROS) production، activation of defense gene expression، structural changes in the cell wall and phytoalexin production. In this study، different aspects of increasing the production of secondary metabolites in cell culture of plants by biotic elicitors is investigated.

Plant production from tissue culture is of high importance from genetic engineering point of view، so in this study، optimization of tissue culture conditions for callus production and plant regeneration of Salsola arbuscula were examined. Seeds were planted MS medium and after two months، roots، stems (internodes) and leaves explants were transferred to the MS medium with different concentration of 2،4-D and Kinetin hormones for production callus. Plant regeneration was also examined on the various media. Results showed that the best medium to induce callus production were medium of MS + 2،4-D (1 mg/L) + Kin (1 mg/L) and the best explants were roots. So، direct shoot regeneration produced in the medium MS + Kin (1 mg/l) and MS + Kin (0. 5 mg/L). Despite production of callus on medium containing only 2،4-D، combined two hormones، auxin and cytokinin، increased the rate of callus production. Also direct shoot regeneration has occurred in medium without auxin. So، production rate of callus and plant regeneration are dependent on amount of external plant growth regulators، and also، amount of external plant growth regulators significantly dependent to genotype and amount of internal plant hormones.

Chromene derivatives are able to growth inhibition and induce apoptosis in different cell types. In this study، we reported a derivative of 4-aryl-4H-chromenes with differentiation and apoptotic activity against NB4، Acute Promyelocytic Leukemia (APL) cell. Matherial and The cells were seeded in 24-well plates at 1×105 cells/well and treated with 1−12 nM of the 2-amino- 4- (3-bromo 4، 5 dimethoxy – phenyl) -3- cyano -7- (dimethylamino) -4H-chromene (3-BMPC). This compound inhibited growth and viability of the cells in dose- and time-dependent manner. 3-BMPC was found to be highly active growth inhibitor with IC50 of 3 nM (72 h) as determined by trypan blue exclusion test. Wright-Giemsa staining and latex particle phagocytosis assay were used to study differentiated cells. Apoptosis was also detected by fluorescent microscope and DNA fragmentation assay. Results indicated that at low concentrations (3 nM) and after 48 h of treatment، NB4 cells were differentiated to monocyte/macrophage lineage. Results of Hoechst 33258 staining also revealed that the compound induced apoptosis at respective IC50 value after 72 h of treatment. Regarding these results، this compound can be proposed as effective agents for more investigation in leukemia treatment

Diabetes as a metabolic disorder affects different tissues and organs، among them the female reproductive tract such as uterus may be a vulnerable organ. This study was undertaken to study the effects of hyperglycemia and insulin therapy on uterus structure، estrous cycle and serum levels of pituitary and ovarian hormones in Wistar rats. Twenty-four female Wistar rats (180-200g) were randomly divided in: control، sham (Citrate buffer i. p)، hyperglycemic (Streptozotocin; 60 mg/kg، i. p) and hyperglycemic+insulin (insulin 20 IU/Kg/day; s. c). At the end of experiment (36 Days) and in diestrus stage، all rats were weighted and blood samples were collected. Thereafter، their right uterus horn was taken out، weighted and then the middle third part of uterine horn was sampled and fixed (Bouein). After histological preparation، the histological and histomorphometrical examination of uterus was performed. Although in comparison with control and hyperglycemic+insulin groups، in hyperglycemic rats body weight، uterus weight and volume، endometrium and myometrium volume were dramatically decreased (p<0. 001) and the serum level of progesterone significantly increased (p<0. 001)، vascular dilation and infiltrating cells resembling plasma cell was also observed. No significant difference was seen between control and insulin treated group for the above parameters. Insulin deficiency، oxidative stress and alteration in the HPG axis which occurs in hyperglycemic condition، may affect the uterus structure. The observed structural changes might well play a significant role in the reproductive difficulties observed during hyperglycemia

Doxorubicin (DOX) is one of the most widely used antineoplasic drugs although it is toxic for different parts of the body like reproductive organs. The aim of this study was to investigate the protective effect of nano-Zinc oxide on doxorubicin-induced reproductive toxicity. Adult male Wistar rats were divided in four groups including one control and three experimental groups. The control group received Saline (i. p). The experimental groups received Doxorubicin (6 mg/kg)، nano-Zinc oxide (5 mg/kg) and Doxorubicin following nano-Zinc oxide respectively. Treatment was performed for 3 days. 28 days after treatment، histological changes in testis were assessed. The DOX group showed disintegrated germinal epithelium، hypoplasia and deformation of cells، and increased interstitial space. Spermatocyte، spermatid and spermatozoid numbers as well as Leydig cell numbers were reduced. Also Dox increased the number of sloughing tubules while it decreased tubule differentiation index (TDI) and spermiation index (SPI). Nano-Zinc oxide treatment resulted in significant improvement of DOX-induced disorders. The protective effect of nano-Zinc Oxide is illuminated in DOX-induced male reproductive system toxicity.

In order to localize and optimize of micro propagation of Gisela 6، a valuable rootstock، the effects of medium، carbon sources، light and method of auxin application on shooting and rooting were investigated. The effect of six media، five carbon sources and three light spectra plus different concentrations of BA and IBA on growth characters including shoot regeneration and their length، were studied using lateral buds as explants.. Percentage of rooting، number and length of roots were surveyed in two 1) pulsing method using IBA and NAA at 1. 0 g. L-1 for different times; and 2) shoot planting on solid medium containing 6 concentrations of IBA and NAA independently. MS was the most suitable medium and the highest and longest shootlet numbers were produced on medium containing 30 gr. L-1 of market sugar and sucrose respectively. White and red light are more effective on shoot regeneration and shoot length respectively. The highest root induction was occurred in pulsing method in presence of 1 g. L-1 of IBA. Optimized shoot propagation was observed on MS medium containing market sugar and BAP under white light، and optimized root induction was occurred in pulsing method in presence of IBA

This research was conducted to investigate changes in single starnded DNA preferring nuclease (SSPN) activity، protein and chlorophyll contents in barley، under salt stress. Tolerant (Sahra) and sensitive (Rayhan) barley cultivars were used in a complete random plot with a factorial design، using 3 replicates at 0 and 120 mM NaCl concentrations. Nuclease activity on ssDNA was measured at pH 5. 6 and 7. 0 in the presence of 1 mM of one of the following divalent cations: Cu2+، Zn2+، Mg2+، Ca2+ and EDTA، by spectrophotometry and native-PAGE assays. The highest enzyme activity was observed in the presence of Ca2+ at 120 mM NaCl and pH 7. 0 and the lowest enzyme activity was observed in the presence of Cu2+ at 0 mM NaCl and pH 5. 6. EDTA inhibited SSPN activity. In the gel assay، 5 enzymes were revealed، amongst which 59، 47 and 43 kD enzyme at both pHs and 34 and 41 kD enzymes were revealed only at pH 7. 0. Na+ content، K+/Na+ ratio and chlorophyll and protein contents decreased significantly upon salt stress in both cultivars. Salt stress caused an increase in the nuclease activity and a decrease in protein and chlorophyll contents in both cultivars. However، these changes were significantly lower in the tolerant cultivar، compared to the sensitive one

The aim of this study was investigation of the presence DBAT gene، a key gene in the biosynthetic pathway of taxol، in yew (Taxus baccata) and its taxol producing endophytic fungus and also assessment the similarity of these sequences with sequences available in GenBank. In this study، endophytic fungi were isolated from the bark of Taxus baccata and purified، using hyphal tip method. Genomic DNA of yew tree and a taxol producing fungus (T9 isolate) was extracted. Using polymerase chain reaction، presence of DBAT gene was investigated. After sequencing، similarity of sequences obtained from yew and T9 isolate with other taxus species and endophyticn fungi sequences، available in GenBank، were compared. Using specific primers، a 125 bp fragment of DBAT gene from Taxus baccata and T9 isolate was amplified. Nucleotide and amino acid sequences alignment showed that theses sequences had a high similarity (over 98%) in fungus and host plant. Alignment results of these sequences with other species of yew trees and endophytic fungi sequences also showed very high similarity (98-100%). Besides، relatively high similarity between the nucleotides and amino acid sequences of DBAT and other acyl/aroyltransferases enzymes involved in taxol biosynthesis were observed. Based on the results، the presence of DBAT gene in taxol producing endophytic fungus and also very high homology of its sequence، in nucleotide and amino acid levels، with host plant (Taxus baccata) and other yew species and fungal endophytes were proved.

During embryonic development، both bird’s feather follicle and mammal’s hair follicle originate by a similar manner، the aim of this research was to access and compare histology، cell growth potential and inductive properties of papilla cells this organs for initiating dermal-epidermal interactions. Feather and hair follicles were provided from house pigeons and PVG rats، respectively. Some of the follicles were processed for histological examination whiles others were used to dissect out their dermal papilla. The dissected dermal papillae were cultured in vitro. The cultured cells were then implanted into papilla-depleted follicles. After 28 days the implanted follicles were histologically examined. Histological surveys revealed that despite some distinct differences، both follicles (feather and hair) share a similar histological structure. Hair’s dermal papilla cells showed a greater rate of growth as well as a higher and denser cell aggregation when compared to that of feather follicles. In contrast to hair papilla، the feather papilla cells were not able to grow a hair fiber in implanted follicles. Despite similarities in embryonic development، histological structure and cell growth in vitro، it seems that the signals coming from cultured dermal cells of a mature bird are not able to be understood by hair follicle epidermal cells and can not initiate dermal-epidermal interactions

The aim of this study was to investigate the effece of mare serum and fetal bovine serum (FBS) on meiotic and fertilization capacity of sheep oocytes in vitro Cumulus Oocyte Complexes (COCs) were recovered from ovaries using slicing method. COC’s were washed three time in maturation medium without any serum supplementation. The COC’s were randomly divided into three groups. Group 1 (n = 170) COC’s were fresh control and cultured in maturation medium without serum supplementation. Group 2 (n = 169) COC’s were cultured in maturation medium supplemented with 10% mare serum. Group 3 (n = 167) COC’s were cultured in maturation medium supplemented with 10% FBS. Cumulus expansion was the index of oocyte maturation. To fertilize the mature oocytes، 24 h after maturation oocytes were transferred to the fertilization medium and then sperm was added to the fertilization medium. Twenty four hours post-fertilization، oocytes were denuded mechanically by gentle pipeting، fixed in a mixture of acetic acid and alcohol، stained for 10 min with 1% (w/v) orcein in 45% acetic acid and examined for their fertilization potential. The rate of oocyte maturation in groups 1، 2 and 3 were 59/82%، 77/55% and 89/27%، respectively. The rate of fertilization in three groups was 19/19%، 39/64% and 50%، respectively. Significant difference was observed between three groups (p < 0. 05). The results showed that the medium contain 10% percent fetal bovine have higher in vitro maturation and fertilization of oocyte rates than mare serum and the control groups