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51.
52.
Plant Growth‐promoting Fungus Penicillium oxalicum Enhances Plant Growth and Induces Resistance in Pearl Millet Against Downy Mildew Disease
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Plant Growth‐promoting Fungus (PGPF) Penicillium oxalicum was isolated from rhizosphere soil of pearl millet and was tested for its ability to promote growth and induce systemic resistance in pearl millet against downy mildew disease. The fungal isolate P. oxalicum UOM PGPF 16 was identified as P. oxalicum using ITS sequencing and morphological analysis and sequence was deposited at NCBI with accession number KF150220. Pearl millet susceptible seeds were treated with three different inducers (CS, CF and LCF) of PGPF P. oxalicum and all the inducers significantly reduced the downy mildew disease and enhanced plant growth. Among the inducers tested, CS treatment recorded highest seed germination of 91% and 1427 seedling vigour followed by LCF and CF treatments. The vegetative growth parameter and NPK uptake studies under greenhouse conditions revealed that the CS treatment of P. oxalicum remarkably enhanced the parameters tested when compared to control plants. A significant disease protection of 62% and 58% against downy mildew disease was observed in plants pretreated with CS of P. oxalicum under greenhouse and field conditions, respectively. The spatio‐temporal studies revealed that inducers P. oxalicum required a minimum of 3 days for developing maximum disease resistance which was maintained thereafter. The maximum Peroxidase (POX) activity (62.7 U) was observed at 24 h in seedlings treated with CS of PGPF P. oxalicum and the activity gradually reduced at later time points after pathogen inoculation. Chitinase (CHT) activity was significantly higher in inducer treated seedlings when compared to control seedlings inoculated with pathogen after 48 h and remained constant at all time points. 相似文献
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T. S. Suryanarayanan T. S. Murali N. Thirunavukkarasu M. B. Govinda Rajulu G. Venkatesan R. Sukumar 《Biodiversity and Conservation》2011,20(5):913-928
Fungal endophytes of tropical trees are expected to be exceptionally species rich as a consequence of high tree diversity
in the tropics and the purported host restriction among the endophytes. Based on this premise, endophytes have been regarded
as a focal group for estimating fungal numbers because their possible hyperdiverse nature would reflect significantly global
fungal diversity. We present our consolidated ten-year work on 75 dicotyledonous tree hosts belonging to 33 families and growing
in three different types of tropical forests of the NBR in the Western Ghats, southern India. We conclude that endophyte diversity
in these forests is limited due to loose host affiliations among endophytes. Some endophytes have a wide host range and colonize
taxonomically disparate hosts suggesting adaptations in them to counter a variety of defense chemicals in their hosts. Furthermore,
such polyphagous endophytes dominate the endophyte assemblages of different tree hosts. Individual leaves may be densely colonized
but only by a few endophyte species. It appears that the environment (the type of forest in this case) has a larger role in
determining the endophyte assemblage of a plant host than the taxonomy of the host plant. Thus, different tropical plant communities
have to be studied for their endophyte diversity to test the generalization that endophytes are hyperdiverse in the tropics,
estimate their true species richness, and use them as a predictor group for more accurate assessment of global fungal diversity. 相似文献
55.
Davis RM Matsumoto S Bernardo M Sowers A Matsumoto K Krishna MC Mitchell JB 《Free radical biology & medicine》2011,50(3):459-468
Nitroxides are a class of stable free radicals that have several biomedical applications including radioprotection and noninvasive assessment of tissue redox status. For both of these applications, it is necessary to understand the in vivo biodistribution and reduction of nitroxides. In this study, magnetic resonance imaging was used to compare tissue accumulation (concentration) and reduction of two commonly studied nitroxides: the piperidine nitroxide Tempol and the pyrrolidine nitroxide 3-CP. It was found that 3-CP was reduced 3 to 11 times slower (depending on the tissue) than Tempol in vivo and that maximum tissue concentration varies substantially between tissues (0.6-7.2mM). For a given tissue, the maximum concentration usually did not vary between the two nitroxides. Furthermore, using electron paramagnetic resonance spectroscopy, we showed that the nitroxide reduction rate depends only weakly on cellular pO(2) in the oxygen range expected in vivo. These observations, taken with the marked variation in nitroxide reduction rates observed between tissues, suggest that tissue pO(2) is not a major determinant of the nitroxide reduction rate in vivo. For the purpose of redox imaging, 3-CP was shown to be an optimal choice based on the achievable concentrations and bioreduction observed in vivo. 相似文献
56.
Ponde DE Su Z Berezov A Zhang H Alavi A Greene MI Murali R 《Bioorganic & medicinal chemistry letters》2011,21(8):2550-2553
EGFR is over-expressed in several solid tumors including breast, prostate, pancreas, and lung cancers and is correlated to the metastasic potential of the tumor. Anti-EGFR receptor-binding peptidomimetics (AERP) were examined to assess the small molecule’s potential use as tumor-specific imaging agents. The aim of this work was to design and characterize the binding specificity of the radiolabeled peptidomimetics to EGFR over-expressing cell lysate and to A431 xenograft tumors. Our newly designed peptidomimetic, AERP, was conjugated to DTPA and labeled with 99mTc. The in vivo tumor accumulation of [99mTc] DTPA-AERP-2 was 1.6 ± 0.1 %ID/g and tumor to muscle ratio was 5.5. Our studies suggest that this novel peptidomimetic, AERP-2, warrants further development as an EGFR specific tumor-imaging agent. 相似文献
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Bauer J Büttner P Murali R Okamoto I Kolaitis NA Landi MT Scolyer RA Bastian BC 《Pigment cell & melanoma research》2011,24(2):345-351
Oncogenic BRAF mutations are more frequent in cutaneous melanoma occurring at sites with little or moderate sun-induced damage than at sites with severe cumulative solar ultraviolet (UV) damage. We studied cutaneous melanomas from geographic regions with different levels of ambient UV radiation to delineate the relative effects of cumulative UV damage, age, and anatomic site on the frequency of BRAF mutations. We show that BRAF-mutated melanomas occur in a younger age group on skin without marked solar elastosis and less frequently affect the head and neck area, compared to melanomas without BRAF mutations. The findings indicate that BRAF-mutated melanomas arise early in life at low cumulative UV doses, whereas melanomas without BRAF mutations require accumulation of high UV doses over time. The effect of anatomic site on the mutation spectrum further suggests regional differences among cutaneous melanocytes. 相似文献
59.
Han X Rozen S Boyle SH Hellegers C Cheng H Burke JR Welsh-Bohmer KA Doraiswamy PM Kaddurah-Daouk R 《PloS one》2011,6(7):e21643
Background
The development of plasma biomarkers could facilitate early detection, risk assessment and therapeutic monitoring in Alzheimer''s disease (AD). Alterations in ceramides and sphingomyelins have been postulated to play a role in amyloidogensis and inflammatory stress related neuronal apoptosis; however few studies have conducted a comprehensive analysis of the sphingolipidome in AD plasma using analytical platforms with accuracy, sensitivity and reproducibility.Methods and Findings
We prospectively analyzed plasma from 26 AD patients (mean MMSE 21) and 26 cognitively normal controls in a non-targeted approach using multi-dimensional mass spectrometry-based shotgun lipidomics [1], [2] to determine the levels of over 800 molecular species of lipids. These data were then correlated with diagnosis, apolipoprotein E4 genotype and cognitive performance. Plasma levels of species of sphingolipids were significantly altered in AD. Of the 33 sphingomyelin species tested, 8 molecular species, particularly those containing long aliphatic chains such as 22 and 24 carbon atoms, were significantly lower (p<0.05) in AD compared to controls. Levels of 2 ceramide species (N16:0 and N21:0) were significantly higher in AD (p<0.05) with a similar, but weaker, trend for 5 other species. Ratios of ceramide to sphingomyelin species containing identical fatty acyl chains differed significantly between AD patients and controls. MMSE scores were correlated with altered mass levels of both N20:2 SM and OH-N25:0 ceramides (p<0.004) though lipid abnormalities were observed in mild and moderate AD. Within AD subjects, there were also genotype specific differences.Conclusions
In this prospective study, we used a sensitive multimodality platform to identify and characterize an essentially uniform but opposite pattern of disruption in sphingomyelin and ceramide mass levels in AD plasma. Given the role of brain sphingolipids in neuronal function, our findings provide new insights into the AD sphingolipidome and the potential use of metabolomic signatures as peripheral biomarkers. 相似文献60.
Dolic K Weinstock-Guttman B Marr K Valnarov V Carl E Hagemeier J Brooks C Kilanowski C Hojnacki D Ramanathan M Zivadinov R 《PloS one》2011,6(11):e28062