Hormonal regulation for callogenesis and organgenesis of Artemisia absinthium L

Callus cultures were induced from leaf and stem explants of Artemisia absinthium, at different auxin and cytokinin concentrations. Moderate concentrations of growth regulators either in combination or insingle in MS medium produced friable, light green and non-embryogenic callus from both explants. These totipotent cells gave rise to shoots when transferred to same or different growth regulator containing medium as second subculture. Complete rooting was achieved on full and half strength basal MS medium supplemented with different auxin concentrations. Synergetic effect of plant growth regulator plays an important role in callus induction and cell differentiation

Comparison of transgenic plant production for bacterial blight resistance in Pakistani local rice (Oryza sativa L.) cultivars

The study was carried out to improve bacterial leaf blight resistance in three rice cultivars (Basmati - 370, DR - 82 and IR - 6) by Agrobacterium mediated transformation system. Three week-old scutellum derived calli were infected with Agrobacterium strain EHA101, containing binary vector pTCL5 which has Xa 21 gene. Different levels of acetosyringone were tested to enhance transformation efficiency. Acetosyringone at 300 ìM showed 56.6% GUS expression with 100 and 200 ìM acetosyringone showing 13.3 and 30.0% GUS expression, respectively. Maximum transformation efficiency was obtained using DR - 82 with calli exposed to 300 ìM acetosyringone for 2 min. Direct hygromycin selection with 48 h ofco-cultivation was superior to pre-selection in all three cultivars. Transient GUS expression was 51.4% while stable GUS expression in calli was 18.8%. PCR analysis confirmed the presence of the Xa 21 gene in transformed regenerated plants. Stable varietal transformation efficiency was DR - 82 > Basmati-370 > IR - 6. Resistance of transgenic plants against Xanthomonas oryzae pathovar oryzae was evaluated with various strains/isolates at the seedling stage. All PCR positive transgenic plants of DR - 82 and Basmati - 370 were resistant with lesion areas less than 5% of the inoculated leaf area. The tested transgenic plants were resistant to all the indigenous and exotic strains tested due to the broad spectrum protection provided by the Xa 21 gene

Evaluation of anticancer activity of Debregeasia Salicifolia extract against estrogen receptor positive cell line

Crude methanol extract and fractions of Debregeasia salicifolia stem were examined for their anticancer activity. To determine anticancer activity, different concentrations of crude extract were tested on MCF- 7 cancer cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. D. salicifolia extract showed a significant antiproliferative activity and a dose dependent effect was observed. Minimum inhibition of 25.31% was shown by extract at concentration 10 ìg/ml and maximuminhibition (99%) was observed at 500 ìg/ml. Hexane, chloroform, ethyl acetate, methanol and aqueous fractions were also tested at a  concentration of 200 ìg/ml. Hexane, chloroform and ethyl acetatefractions appeared to be most active with 90 to 99% activity. These results indicate the possible potential use of D. salicifolia as antineoplastic agent. Preliminary phytochemical screening revealed the chemical composition of D. salicifolia extract containing flavonoids, anthraquinones and tannins.Anticancer properties of D. salicifolia can be linked with the presence of these chemicals.Key words: Anticancer, cytotoxic, Debregeasia salicifolia, MCF-7 cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, phytochemical

Biological activities of Rumex dentatus L: Evaluation of methanol and hexane extracts

Rumex dentatus L. (Plygonaceae) extracts were evaluated for antibacterial, antifungal, cytotoxic, antitumor and allopathic potential. The leaf, stem and root extracts were prepared in methanol and hexane by simple maceration. The methanol extracts of root and shoot were found effective against all the bacterial strains tested. Zone of inhibition ranged between 9.7 to 12.1 mm. While the hexane extracts inhibited fungal growth (up to 80%) more efficiently than the methanol extracts. Concentration of different the extracts of R. dentatus effectively inhibited tumor induction on the potato discs produced by wild type Agrobacterium strains At10 and At6. The root extracts either in methanol or hexane showed LD50 values below 1000 ppm in brine shrimp mortality assay. The methanol extracts of leaf and stem inhibited radish seed germination (70 and 61% respectively) and root length more than the hexane extracts. The R. dentatus methanol extract showed presence of alkaloids, saponins, anthraquinones and tannins while flavonoids were also found in both methanol as well as hexane extract

What molecular mechanism is adapted by plants during salt stress tolerance?

Salt stress harmfully shocks agricultural yield throughout the world affecting production whether it is for subsistence or economic outcomes. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyper-osmolarity and ion disequilibrium. Salt tolerance and yield stability are complex genetic traits that are difficult to establish in crops since salt stress may occur as a catastrophic episode, be imposed continuously or intermittently and become gradually more severe at any stage during development. Molecular biology research has provided new insight into the plant response to salinity and identified genetic determinants that effect salt tolerance. Recent confirmation that many salt tolerance determinants are ubiquitous in plants has led to the use of genetic models, like Arabidopsis thaliana, to further dissect the plant salt stress response. Since manyof the most fundamental salt tolerance determinants are those that mediate cellular ion homeostasis, this review will focus primarily on the functional essentiality of ion homeostasis mechanisms in plantsalt tolerance. The transport systems that facilitate cellular capacity to utilize Na+ for osmotic adjustment and growth and the role of the Salt-Overly-Sensitive (SOS) signal transduction pathway in the regulation of ion homeostasis and salt tolerance will be particularly emphasized. The objective of the review is to know “What molecular mechanism is adopted by plants during salt stress tolerance?” A conclusion will be presented that integrates cellular based stress signaling and ion homeostasis mechanisms into a functional paradigm for whole plants and defines biotechnology strategies for enhancing salt tolerance of crops

An Energy Performance Evaluation of Commercially Available Window Glazing in Darwin’s Tropical Climate

A total of 40% of the world’s energy produced is utilized to maintain thermal comfort for the occupants of the building. Governments are taking measures collectively to regulate energy efficient buildings to reduce carbon emissions globally. Windows account for more than half of total energy losses in the buildings. The employment of energy efficient glazing in the construction industry is not common in Australia. This paper investigates several types of commercially available windows and their effectiveness in the hot and humid climate of Darwin. Although extensive literature is available for cold regions, these windows have not been studied in hot and humid climates such as the climate in Darwin. Building cooling loads of an academic building were calculated using Autodesk Revit Architecture and Carrier HAP. Double glazed variants offered approximately a 5% reduction in cooling loads and had a payback period of nearly 7 to 9 years, depending on the type of gas used to fill the pane cavity. The results indicate that triple glazed, or aerogel-based windows will provide about 11–12 % of energy saving in cooling loads. These can be a viable alternative and have a payback period of 11 years, while their average service life expectancy is 30 years. It was found that the feasibility of efficient glazing depends on market price, building usage, and energy efficiency of an overall building envelope

Haptic Perception of Object Curvature in Parkinson's Disease

The haptic perception of the curvature of an object is essential for adequate object manipulation and critical for our guidance of actions. This study investigated how the ability to perceive the curvature of an object is altered by Parkinson's disease (PD).Eight healthy subjects and 11 patients with mild to moderate PD had to judge, without vision, the curvature of a virtual "box" created by a robotic manipulandum. Their hands were either moved passively along a defined curved path or they actively explored the curved curvature of a virtual wall. The curvature was either concave or convex (bulging to the left or right) and was judged in two locations of the hand workspace--a left workspace location, where the curved hand path was associated with curved shoulder and elbow joint paths, and a right workspace location in which these joint paths were nearly linear. After exploring the curvature of the virtual object, subjects had to judge whether the curvature was concave or convex. Based on these data, thresholds for curvature sensitivity were established. The main findings of the study are: First, 9 out 11 PD patients (82%) showed elevated thresholds for detecting convex curvatures in at least one test condition. The respective median threshold for the PD group was increased by 343% when compared to the control group. Second, when distal hand paths became less associated with proximal joint paths (right workspace), haptic acuity was reduced substantially in both groups. Third, sensitivity to hand trajectory curvature was not improved during active exploration in either group.Our data demonstrate that PD is associated with a decreased acuity of the haptic sense, which may occur already at an early stage of the disease

Clinical implication of HLA class I expression in breast cancer

<p>Abstract</p> <p>Background</p> <p>Human leukocyte antigen (HLA)-class I molecules on tumor cells have been regarded as crucial sites where cytotoxic T lymphocytes (CTL) can recognize tumor-specific antigens and are strongly associated with anti-tumor activity. However, the clinical impact of HLA class I expression in breast cancer has not been clarified.</p> <p>Methods</p> <p>A total of 212 breast cancer patients who received curative surgery from 1993 to 2003 were enrolled in the current study. HLA class I expression was examined immunohistochemically using an anti-HLA class I monoclonal antibody. The correlation between HLA class I positivity and clinical factors was analyzed.</p> <p>Results</p> <p>The downregulation of HLA class I expression in breast cancer was observed in 69 patients (32.5%). HLA class I downregulation was significantly associated with nodal involvement (p < 0.05), TNM stage (p < 0.05), lymphatic invasion (p < 0.01), and venous invasion (p < 0.05). Patients with preserved HLA class I had significantly better disease-free interval (DFI) than those with loss of HLA class I (p < 0.05). However, in multivariable analysis, HLA class I was not selected as one of the independent prognostic factors of disease-free interval.</p> <p>Conclusion</p> <p>The examination of HLA class I expression is useful for the prediction of tumor progression and recurrent risk of breast cancer via the antitumor immune system.</p

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)