14 research outputs found

    High frequency Agrobacterium mediated genetic transformation in rubber tree via. vacuum infiltration

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    In a tree species like Hevea brasiliensis, genetic transformation offers a viable approach for crop improvement within a short period. Hevea being highly recalcitrant to in vitro culture, an efficient transformation protocol is necessary for generating large number of transgenic plants with stable foreign gene expression. After several modifications in the initial transformation protocol, the transformation frequency was increased to 14 per cent using proliferated anther callus. Therefore, vacuum infiltration was attempted for enhancing the transformation frequency. In the present work the conditions for vacuum infiltration viz. vacuum pressure and period of infiltration were standardized. Vacuum infiltration at 30 psi pressure for 10 minutes was found to be ideal for getting high frequency transformation in H. brasiliensis. Irrespective of the gene constructs experimented, transformation frequency was significantly improved by adopting vacuum infiltration. Employing this technique, the transformation efficiency of MnSOD gene construct with FMV34S promoter could be enhanced from 14 to 50 percent

    Induction of callus and plant regeneration in Vicoa indica

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    Callus cultures were initiated from the stem and leaf explants of aseptically grown Vicoa indica. A simple method is described for plant regeneration from callus and the rapid multiplication of the plants thus obtained. Callus initiation was optimum in Gamborg B5 (B5) basal medium containing either 2.0mgl12.0 mg\hspace{2mm} l^{-1} naphthaleneacetic acid (NAA) with 0.2mgl10.2 mg\hspace{2mm} l^{-1} kinetin (Kn) or 2.0mgl12.0 mg\hspace{2mm} l^{-1} 6-benzylaminopurine (BAP) with 0.2mgl10.2 mg\hspace{2mm} l^{-1} NAA. The calli initiated on B5 medium were able to proliferate on both Murashige and Skoog (MS) and B5 basal medium. Shoot primordia were obtained from greenish callus on passage to B5 basal medium containing 3.0mgl13.0 mg\hspace{2mm} l^{-1} BAP and 1.0mgl11.0 mg\hspace{2mm} l^{-1} Kn. On further subculture onto B5 medium containing 0.2mgl10.2 mg\hspace{2mm} l^{-1} Kn the shoot primordia developed into plantlets

    Hypothermia due to limbic system involvement and longitudinal myelitis in a case of Japanese encephalitis: a case report from India

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    Santhosh Narayanan,1 NK Thulaseedharan,1 Gomathy Subramaniam,2 Geetha Panarkandy,1 VK Shameer,1 Arathi Narayanan1 1Department of General Medicine, 2Department of Radiodiagnosis, Government Medical College, Kozhikode, Kerala, India Abstract: Japanese encephalitis (JE) is an infectious encephalitis prevalent in Asia. It usually presents with fever, headache, convulsions and extrapyramidal symptoms. Limbic system involvement and hypothermia though common in autoimmune encephalitis have never been reported in JE. We report a case of an 18-year-old girl with no previous comorbidities who presented to us with a history of fever and headache for 1 week duration. She developed bilateral lateral rectus palsy and asymmetric flaccid weakness of all four limbs, after 2 days of admission, which was followed by altered sensorium and intermittent hypothermia. Neuroimaging revealed longitudinal myelitis extending from pons till the L1 level along with bilateral thalamic hemorrhage in brain. Cerebrospinal fluid (CSF) was positive for IgM antibody to JE virus. She was treated with supportive measures, but she developed intractable hypothermia and seizures and succumbed to illness after 2 weeks of admission. Keywords: Japanese encephalitis, hypothermia, limbic syste

    Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production

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    Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used e.g. as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l-1 sucrose, 0.5 mg l-1 of the auxin 1-naphthalene acetic acid and 0.5 mg l-1 of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230 %) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures
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