101 research outputs found
Chemistry of hydrazine adducts of bicyclo [3.3.1] nonadiene diones and an approach to the synthesis of some bridged heterocyclic annulenes
No full textThe literature concerning polyamines and some bridged cyclic amines of biological importance is reviewed. The structure of the dihydrazone 4,9dimethyl-2,3,7,8-tetraazatetracyclo[7.3.1.0.4,1206,10]trideca-l,6-dieneprepared by the reaction of hydrazine with 4,8-dimethylbicyclo[3.3.1]nona3,7-diene-2,6-dione was established. This hydrazone has two double bonds at bridgehead positions (anti Bredt). The reduction of 4,9-dimethyl-2,3,7,8-tetraazatetracyclo[7.3.1.0.4,1206,10]trideca-l,6-diene to give the dihydrazine 1,6-dimethyl-2,3,7,8-tetraazatetracyclo[7.3.1.0.4,1206,10]tridecane was investigated. Reduction of the dihydrazone using lithium aluminium hydride and aluminium chloride gave the dihydrazine but lithium aluminium hydride alone or aluminium chloride alone induced the ring cleavage of the dihydrazone to afford tricyclic dihydro pyrazoles. The oxidation of the dihydrazine and reaction with aldehydes were also examined. The oxidation gave the bridged bisazoalkane 1,6-dimethyl-2,3,7,8-tetraazatetracyclo[7.3.1.0 4,1206,10]trideca-2,7-diene and the reactions of the dihydrazine with aldehydes gave products with further cyclisation. In Part Two, the literature of bridged heterocyclic annulenes is reviewed. Aspects of the chemistry of the readily available bridged l,5-benzodiazepine 4,6-dimethyl-5,2,8-ethanylylidene-5H-1,9-benzodiazacycloundecine are described. The allylic bromination of this bridged 1,5-benzodiazepine gave the dibromide 4,6-dibromomethyl-5,2,8-ethanylylidene-5H-1,9-benzodiazacycloundecine in good yield. Transformations of this dibromide by a series of nucleophiles gave products with formation of extra carbocyclic rings, and extra heterocyclic rings with incorporation of one or two further nitrogen groups. The chemistry of these bridged systems was extensively studied and led to a synthesis of a benzo[14] annulene.</p
Agrobacterium tumefaciens-mediated transformation of axillary bud callus of Hibiscus rosa-sinensis L. ‘Ruby’ and regeneration of transgenic plants
No full textHibiscus rosa-sinensis L. is a popular ornamental species valued for its large brightly coloured ephemeral flowers and has a range of health-promoting properties. The value of H. rosa-sinensis could be improved even further if there were ways to prolong the display life of its short-lived flowers, and to improve its frost tolerance. Development of an efficient plant transformation and regeneration procedure that allows introduction of genes into the plant will greatly facilitate this. Here we outline a transformation and regeneration procedure that is the first to produce transformed H. rosa-sinensis plants successfully. We first optimised callus induction and shoot regeneration efficiency. The highest shoot regeneration frequency of 66.7 % was achieved in the cultivar ‘Ruby’ when callus induced from axillary buds using a basal medium supplemented with 2.22 μM benzylaminopurine and 2.47 μM β-naphthoxyacetic acid was cultured on shoot regeneration medium. The frequency of shoot regeneration from callus was lower in ‘Ben James’ and absent in ‘Bright Light’, indicating genotypic differences. When axillary bud-derived callus of ‘Ruby’ was co-cultured with Agrobacterium tumefaciens harbouring a β-glucuronidase (GUS) reporter plasmid, 49 % of calli produced shoots on selection media. All tested plantlets were confirmed as transformed based on the presence of the GUS transgene in the genomic DNA and GUS activity measurements. Roots were induced on transgenic plantlets using half-strength basal medium supplemented with 2.85 μM indole-3-acetic acid. This simple protocol can be used to improve the ornamental, agronomic and health-promoting traits of H. rosa-sinensis hitherto recalcitrant to A. tumefaciens-mediated transformation
Factors affecting somatic embryogenesis in eight Italian grapevine cultivars and the genetic stability of embryo-derived regenerants as assessed by molecular markers
No full textEmbryogenic cultures have been used in cryopreservation, genetic transformation, propagation, virus elimination, induced mutagenesis and in many other biotechnological applications, providing excellent opportunities for biotechnology advances in grapevine. Unfortunately the efficiency of somatic embryo- genesis (SE) is genotype-dependent in addition to showing interaction with explant type used and the plant growth regulator (PGR) composition. In order to identify the interaction of these parameters in SE, we tested eight wine grapevine cultivars, three explant types (ovary, anther/filament and stigma/style) and four PGR combinations in a statistically designed experiment. The genotype was the major deter- mining factor, with embryogenic response varying from 0.1 to 5.1% (about 50-fold difference). For PGR composition of the medium, embryogenesis ranged between 0.5 and 3.3% (a ≈7-fold difference). The explant type was the least important factor with embryogenesis ranging between 0.8% (anther/filament) and 2.3% (ovary)—only a ≈3-fold change. Anther/filament, that had generally been considered to be the most promising explant, surprisingly gave the lowest embryogenesis percentage. Genetic homo- geneity of plants developed from in vitro SE was assessed in comparison to mother plants using six inter-simple sequence repeat and ten random amplified polymorphic DNA primers that produced repro- ducible and clear bands ranging from 150 to 3500 bp. The amplification products were monomorphic across all the regenerated plants and their respective mother plants confirming the genetic homogeneity of the regenerants and demonstrating the suitability of SE for in vitro grapevine germplasm conservation and propagation
Most Discussed Topics - in parliament in August 2023
No full textThis infographic is available in English, Sinhala and Tamil.This Infographic shows the most discussed topics in the 9th Parliament in August 2023 and the MPs who contributed the most to those topics. Topics and contributors are National Heritage, Media and Sports (Buddhika Pathirana - SJB), Governance, Administration and Parliamentary affairs (Chaminda Wijesiri - SJB), Trade and Industry (Ranjith Siyambalapitiya - SLPP), Economy and Finance (Ranjith Siyambalapitiya - SLPP) and Rights and Representation (Ramesh Pathirana -SLPP)
Most Active MPs in Parliament in August 2023
No full textThis infographic is available in English, Sinhala and Tamil.This Infographic shows the Most Active MPs of the 9th Parliament in August 2023. They are Buddhika Pathirana, Ranjith Siyambalapitiya, Premanath C. Dolawatte, Susil Premajayantha, and Lakshman Kiriella. Buddhika Pathirana is the most contributed MP in the Parliament in August 2023
Understanding The Significance Of Pre-Treatment In The Post-Cryopreservation Survival Of Kiwifruit Shoot Tips Through Biochemical And Ultrastructural Studies
No full textThe number of vegetatively propagated species conserved by cryopreservation is increasing thanks to the development of vitrification-based methods in recent years. Although the most economically important horticultural crop in New Zealand is kiwifruit (Actinidia spp.), there is currently no cryopreserved collection of its genetic resources. The field collections of kiwifruit are limited to a few countries and are at a high risk of genetic erosion due to diseases such as Pseudomonas syringae pv. actinidiae. An alternative method of ex situ conservation is through in vitro collections but these are prone to contamination and somaclonal variation, and require maintenance through subculture. Cryopreservation is considered the only method available for the long-term preservation of clonally propagated species while maintaining their genetic fidelity. As cryopreservation outcomes can be species and genotype-specific, understanding biochemical and cell ultrastructural changes during cryopreservation is important for the successful development of protocols for the establishment of a kiwifruit germplasm collection in cryo-storage. Among different vitrification-based cryopreservation techniques, droplet vitrification is becoming the preferred method for many species, as it ensures fast freezing and thawing rates that are vital for vitrification of tissue, but it has not been tested in kiwifruit yet. This research aimed to develop a droplet vitrification protocol for kiwifruit using A. chinensis ‘Hort16A’ as a model, by optimising different pre-treatments to enhance the survival after cryopreservation and assessing the levels of enzymatic and non-enzymatic oxidative markers as well as quantification of oxidative damage and ultrastructural changes. Cold acclimation of donor plants at 4 °C for 2 weeks followed by daily increasing sucrose preculture (0.25, 0.5, 0.75 and 1.0 M) of 1-2 mm shoot tips and supplementation of ascorbic acid (0.4 mM) in all media throughout the procedure registered 40 % regeneration after cryopreservation against 0 % regeneration in shoot tips without any pre-treatment. One-hour treatment of shoot tips in a modified vitrification solution at 0 °C is another important step in the protocol. All the antioxidant markers showed a significant increase in pretreated shoot tips compared to non-pretreated shoot tips throughout the steps, especially 24 h after recovery from cryopreservation. Oxidative damage markers, lipid peroxides and protein carbonyls were significantly lower in pretreated shoot tips than in non-pretreated shoot tips after cryopreservation. suggesting better protection as a result of pre-treatment and ascorbic acid supplementation. Transmission electron microscopic images of the ultrastructure after cryopreservation showed damage in cell organelles of all cells of non-pretreated shoot tips whereas, some cells in pretreated shoot tips had structural integrity confirming the results of oxidative marker assays and recovery after cryopreservation. These observations show that pre-treatment is necessary to ensure survival after droplet vitrification of Actinidia species. Testing the applicability of this protocol to other A. chinensis genotypes and then to other Actinidia species, and further research to improve it would pave the way for the establishment of a cryopreserved Actinidia collection
Plant Biotechnology and Crop Improvement
No full text“Plant Biotechnology and Crop Improvement" compiles research and reviews from a Plants Special Issue, showcasing diverse studies on plant biotechnology's latest breakthroughs. To tackle global challenges like climate change and food security, biotechnology supplements traditional breeding. As the need for sustainable, resilient crop varieties becomes increasingly urgent, this reprint showcases the transformative potential of biotechnological interventions in enhancing crop productivity, nutritional quality, and sustainability. Exploring mutagenesis, genomics, gene editing, metabolomics, and synthetic biology revolutionizes agriculture. Crops from various continents, enhancing nutrition in staple crops, such as wheat, cassava, sweet potato, and beans can be discovered or lesser-known species like African tef or prickly pear can be explored. Ethical, socio-economic, and environmental impacts are discussed, offering a balanced view of genetic modification. This reprint is highly recommended for researchers, students, policymakers, and industry professionals as it provides insights into the forefront of plant biotechnology, guiding towards a more sustainable agricultural future
Contribution in Parliament - June 2024
No full textThis infographic is available in English and Sinhala.This infographic shows the overall contribution of MPs in 9th parliament in June 2024. As per the analysis, 71 MPs did not contribute at all during June 2024. This infographic indicates the top 5 contributors of the month. They were Susil Premajayantha (SLPP), Sajith Premadasa (SJB), Buddhika Pathirana (SJB), Kanchana Wijesekara (SLPP) and Ranjith Siyambalapitiya (SLPP)
Auteur theory and Director Pa. Ranjith: Deconstructing the Reality
No full textFilm is one of the mediums which reflect the directors’ ideology. A film director through her/his film conveys the opinion and ideology to the target audience. In comparison to other media, film has gained popularity throughout history and has evolved over time. Director is the pioneer for illustrating how films can deconstruct the reality of society in various fields. The director sets his/her plot to build and convey directors’ own ideology in the natural setting. The researcher has used descriptive content analysis to analyze the selected films of director Pa. Ranjith to analyze the qualitative data. As the theoretical framework of this study, the researcher uses the Auteur Theory, which examines the control of the author over his/her media productions. This research mainly focuses on finding out how director Pa. Ranjith deconstructs the reality through his films based on auteur theory. The hypothesis of this research is that director Pa. Ranjith uses many strategies and techniques to convey his idea to the audience. Through directors’ films, the audience can find out how the director brings the idea to the target audience using real issues like caste, religion, nationality, etc through Auteur theory. Pa. Ranjith’s selection of theme, plot, characterization and language differentiates him from other Tamil directors. Auteur theory helps to discern Pa. Ranjith’s ideology about issues he has chosen. Pa. Ranjith’s films which reflect Tamil society and Tamil culture create awareness and expectation of reality for people who become victimized by the social structure, culture and tradition including the caste and class statutes, and challenges of so called lower caste people for survival in Tamil society.
DOI: http://doi.org/10.31357/fhss/vjhss.v07i01.1
Most discussed topics in Parliament in April 2024
No full textThis infographic is available in English and Sinhala.This Infographic shows the most discussed topics in the 9th Parliament in April 2024 and the MPs who contributed the most to those topics. Topics and contributors are Justice, Defence and Public Order (Tiran Allas - SLPP), Governance, Administration and Parliamentary Affairs (Madhura Withanage - SLPP), Health (Ramesh Pathirana - SLPP), Economy and Finance (Ranjith Siyambalapitiya - SLPP), and Rights and Representation (S. Viyalanderan - SLPP)
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