Phosphinothricin resistance in Aspergillus niger and its utility as a selectable transformation marker
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Title |
Phosphinothricin resistance in Aspergillus niger and its utility as a selectable transformation marker
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Creator |
AHUJA, M
PUNEKAR, NS |
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Subject |
l-methionine sulfoximine
amino-acid oxidase glutamine-synthetase neurospora-crassa genetic-transformation bialaphos resistance chlamydomonas-reinhardtii manganese peroxidase herbicide-resistant glufosinate |
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Description |
Aspergillus niger is moderately susceptible to inhibition by phosphinothricin (PPT)-a potent inhibitor of glutamine synthetase. This growth inhibition was relieved by L-glutamine. PPT inhibited A. niger glutamine synthetase in vitro (K-I, 54 mu M) and the inhibition was competitive with L-glutamate. The bar gene, imparting resistance to PPT, was successfully exploited as a dominant marker to transform this fungus. Very high PPT concentrations were required in the overlay for selection. Apart from bar transformants, colonies spontaneously resistant to PPT were frequently encountered on selection media. Reasons for such spontaneous resistance, albeit of moderate growth phenotype, were sought using one such isolate (SRPPT). The SRPPT isolate showed a 2-3-fold decrease in its glutamate uptake rate. Elevated external glutamate levels further suppressed the PPT-induced growth inhibition. Cellular entry of PPT could be through the L-glutamate uptake system thereby accounting for the observed spontaneous resistant phenotype. These results were useful in the fine-tuning of bar-selection in A. niger. (C) 2008
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Publisher |
ACADEMIC PRESS INC ELSEVIER SCIENCE
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Date |
2011-07-12T16:37:54Z
2011-12-26T12:48:59Z 2011-12-27T05:34:33Z 2011-07-12T16:37:54Z 2011-12-26T12:48:59Z 2011-12-27T05:34:33Z 2008 |
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Type |
Article
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Identifier |
FUNGAL GENETICS AND BIOLOGY, 45(7), 1103-1110
1087-1845 http://dx.doi.org/10.1016/j.fgb.2008.04.002 http://dspace.library.iitb.ac.in/xmlui/handle/10054/3383 http://hdl.handle.net/10054/3383 |
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Language |
en
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