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| Delgado-Virgen,Francisco; Guzman-de-Peña,Doralinda. |
| External pH constitutes one of the most important environmental factors that control growth, metabolism and differentiation in microorganisms, including fungi. We have analyzed the effect of external pH on sterigmatocystin biosynthesis in Aspergillus nidulans. It was observed in repeated experiments that alkaline pH, in opposition to acid pH, increased sterigmatocystin production and the transcript levels of aflR, the master gene that regulates expression of the sterigmatocystin cluster in A. nidulans. It is known that pH effects in fungi operate mostly through the Pal/Pac signaling pathway, originally described in Aspergillus nidulans. Accordingly, we studied the role of this signaling pathway in ST biosynthesis. It was observed that aflR transcript... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aspergillus nidulans; PH; Sterigmatocystin; PacC. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000400027 |
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| Maccheroni Jr.,Walter; Araújo,Welington Luiz; Azevedo,João Lúcio. |
| In fungi a genetic system ensures that enzymes are secreted mainly at ambient pH values corresponding to their optima of activity. Although a great deal of information has been obtained concerning this environmental response, there is a lack of studies involving phytopathogenic, endophytic and entomopathogenic fungi as well as different aspects of fungus-host interactions. This study compares in a plate-clearing assays, the effect of ambient pH in the secretion of amylase, cellulase, lipase, pectinase and protease by endophytic, phytopathogenic, and entomopathogenic isolates belonging to several species of Colletotrichum. All enzymes were secreted in a pH-dependent manner by all isolates. Endophytes and pathogens showed distinct patterns of protease... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glomerella; Enzyme secretion; Endophytes; Pathogenic fungi; PacC. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000300010 |
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