Rosna Mat Taha

TiO2/Chitosan-NH4I(+I2)-BMII-Based Dye-Sensitized Solar Cells with Anthocyanin Dyes Extracted from Black Rice and Red Cabbage

Dye sensitized solar cells (DSSCs) were fabricated using anthocyanin dye and polymer electrolyte with ammonium iodide (NH4I) salt. The study was designed to focus on increasing the efficiency of the DSSC. DSSC using 26.9 wt. % chitosan-22 wt. % NH4I(

The relationship between polyploidy and organogenetic potential in embryo- and root-derived tissue cultures of Vicia faba L.

The cell cycle was examined in embryo and root explants of Vicia faba in culture to test whether or not polyploidy and aneuploidy affected organogenetic potential. Nuclear DNA contents and the mitotic index were measured in the 0–1 mm apical segment of primary roots of 5-day old seedlings and at various times following transfer to modified MS in darkness or Chus N6 medium in an 8 h light/16h dark cycle (N6-MS programme) at 20°C. Mature embryos were dissected and cut longitudinally. Each half was cultured on the N6-MS programme. Root explants grown on MS in darkness developed into callus but there was no subsequent organogenesis. Only on the N6-MS programme were new roots initiated from root-derived callus. Using the N6-MS programme, embryo-derived callus became green and after 3 to 4 months, produced roots and shoots. Approximately 40% of these cultures regenerated plantlets. Polyploidy occurred within 24 h of culture irrespective of both tissue source and culture protocol. Variations in chromosome number from 2n=2x=12 were also routinely observed. Thus, calluses had the ability to initiate roots and shoots regardless of persistent polyploidy and aneuploidy. Compared with the baseline of cell cycle data for roots in vivo, the proportions of cells in the different cell cycle phases remained constant. Thus, in V. faba induction of organogenesis seems more related to culture protocols than to specific changes to the cell cycle. The mitotic index was significantly lower in vitro compared with meristems of intact roots.

Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

The membranes 55 wt.% chitosan-45 wt.% , 33 wt.% chitosan-27 wt.% -40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.% -50 wt.% buthyl-methyl-imidazolium-iodide (BMII) exhibit conductivity of , , and S , respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO//polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

Plant Regeneration and Cellular Behaviour Studies in Celosia cristata Grown In Vivo and In Vitro

Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants.

Effect of Picloram, Additives and Plant Growth Regulators on Somatic Embryogenesis of Phyla nodiflora (L.) Greene

The present study describes the plant regeneration via somatic embryogenesis in suspension culture der ived from the leaf and stem explants of Phyla nodiflora . The medium type, plant growth regulators, complex extract (coconut milk and malt extract) and anti-oxidant (activated charcoal, ascorbic acid, Polyvinylpyrrolidone and cacid) markedly influenced the embryo regeneration of P. nodiflora . MS with 2,4-D and activated charcoal (10 mg/L) ga ve the highest stimulation of embryogenic callus growt h. Optimized callus was transfered into suspension culture, which showed the globular, heart shaped embryos in MS with 2,4-D + BA + picloram (0.1 mg/L), coconut m ilk (10 ml/L), citric acid (100 mg/L) on 6 th subcultures. Further development stages such as to rpedo and cotyledonary stage embryos and fostered maturation of embryos we re observed at 8 th and 10 th subculture. However, the high frequency embryo germination and plantlet (45 plant s/20 mg cotyledonary stages embryos) formation was obtained in half-strength MS medium without growth regulator s from cotyledonary embryos. All the plantlets esta blished in the field exhibited morphological characters simila r to those of the mother plant.

Optimization of Extraction Parameters by Using Response Surface Methodology, Purification, and Identification of Anthocyanin Pigments in Melastoma malabathricum Fruit

Anthocyanins not just have various benefits in food industry but also have been used as natural colourants in cosmetic, coating products and as potential natural photosensitizers in solar cell. Thus, the main purpose of this study was to obtain information on the maximum yield of anthocyanin that can be recovered from Melastoma malabathricum fruit. Factors such as extraction temperature, extraction time, and solid to liquid ratio were identified to be significantly affecting anthocyanin extraction efficiency. By using three-level three-factor Box-Behnken design, the optimized conditions for anthocyanin extraction by acidified methanol (R 2 = 0.972) were temperature of 60°C, time of 86.82 min, and 0.5 : 35 (g/mL) solid to liquid ratio while the optimum extraction conditions by acidified ethanol (R 2 = 0.954) were temperature of 60°C, time of 120 min, and 0.5 : 23.06 (g/mL) solid to liquid ratio. The crude anthocyanin extract was further purified by using Amberlite XAD-7 and Sephadex LH-20 column chromatography. Identification of anthocyanins revealed the presence of cyanidin dihexoside, cyanidin hexoside, and delphinidin hexoside as the main anthocyanins in M. malabathricum fruit.

Irradiation effect on in vitro organogenesis, callus growth and plantlet development of Gerbera jamesonii

The present work was carried out to study the effects of gamma irradiation on in vitro growth of explants, callus and the formation of shoots and plantlets. Irradiation is known to exhibit or inhibit the differentiation of cells and growth of plants in vitro, which helps in producing new plant varieties. Gamma irradiation is one of the physical mutagens that are widely used for mutation breeding. A gradual decline was observed in the number of shoots regenerated from irradiated petiole explants compared to control. Numbers of shoots regenerated from irradiated petiole explant cultured on Murashige & Skoog medium supplemented with 2.0 mg L-1 BAP and 0.5 mg L-1 NAA was reduced to 6.6±0.9 from 7.5±0.4 (control) when explants were exposed to 20 Gray of irradiation dose. Similar observation was reported on effects of gamma irradiation on in vitro propagated plantlets. Gradual decline was observed based on plant height as the dose of gamma irradiation increased. A significant decline was observed in the fresh weight of irradiated callus compared to control. In this case, growth responses of callus were strongly influenced by the radiation dose. The fresh weight of callus was reduced to 76.4±2.2% compared to 89.7±0.5% of control when callus tissues were exposed to 20 Gy.

Production of gymnemic acid depends on medium, explants, PGRs, color lights, temperature, photoperiod, and sucrose sources in batch culture of Gymnema sylvestre.

Gymnema sylvestre (R.Br.) is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA). The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L) and KN (0.5 mg/L). Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w) was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w). Maximum GA production (58.28 mg/g d.w) was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors.

Effects of benzylaminopurine and naphthalene acetic acid on proliferation and shoot growth of pineapple ( Ananas comosus L. Merr) in vitro

This study was conducted to evaluate the pineapple regeneration and shoot growth as affected by 6- benzylaminopurine (BAP) at 2.0 mg/l and naphthalene acetic acid (NAA) at 0.2 mg/l in vitro. BAP and NAA at the concentration of 2.0 and 0.2 mg/l were used in this study. BAP at 2.0 mg/l significantly affected the production of shoots per explant, shoot length and weight. Total shoot length was higher in BAP (2 mg/l) than in control (MS medium without hormone) and NAA (0.2mg/l) after 10, 20, 30, 40, 50 and 60 days incubation period. Total shoot length was highest in BAP in all incubation periods. Total shoot weight was higher in BAP (2 mg/l) and lower in NAA (0.2 mg/l) as compared to MS medium without hormone. The results showed that BAP at the concentration of 2 mg/l was effective for pineapple shoot growth and development. Key words: Pineapple regeneration, shoot growth, 6-benzylaminopurine, naphthalene acetic acid.

Antioxidant and antibacterial activities of ethanolic extracts of Asparagus officinalis cv. Mary Washington: Comparison of in vivo and in vitro grown plant bioactivities.

Medicinal plants are important elements of indigenous medical system that have persisted in developing countries. Many of the pharmacological principles currently used as anticancer agents were first isolated from plants. However, some important anticancer agents are still extracted from plants because they cannot be synthesized chemically on a commercial scale due to their complex structures that often contain several chiral centers. The aim of this study was to test different extracts from the leaves of Moringa or drumstick tree ( Moringa oleifera ) for activity against leukemia and hepatocarcinoma cells in vitro . The extracts could kill majority (70 - 86%) of the abnormal cells among primary cells harvested from 10 patients with acute lymphoblastic leukemia (ALL) and 15 with acute myeloid leukemia (AML) as well as a culture of hepatocarcinoma cells (75% death), but most significantly by the hot water and ethanol extracts. In conclusion, M. oleifera may have potential for use as source of natural treatment for diseases such as cancer.