Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei
Erysiphe graminis f. sp. hordei, the causal agent of barley powdery mildew, is an obligate biotroph. On arrival on the host, a primary germ tube (PGT) emerges from the conidium. An appressorial germ tube (AGT) then appears, forms an appressorium, and effects host penetration. Such developmental prec...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Published: |
1999
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| Online Access: | http://hdl.handle.net/20.500.11937/5779 |
| _version_ | 1848744891972059136 |
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| author | Hall, A. Bindslev, L. Rouster, J. Rasmussen, S. Oliver, Richard Gurr, S. |
| author_facet | Hall, A. Bindslev, L. Rouster, J. Rasmussen, S. Oliver, Richard Gurr, S. |
| author_sort | Hall, A. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Erysiphe graminis f. sp. hordei, the causal agent of barley powdery mildew, is an obligate biotroph. On arrival on the host, a primary germ tube (PGT) emerges from the conidium. An appressorial germ tube (AGT) then appears, forms an appressorium, and effects host penetration. Such developmental precision may be due to multiple, plant-derived signals and to endogenous tactile and chemical signals. The transduction mechanism remains obscure. The isolation of an expressed sequence tag (EST) homologue of the catalytic subunit of cyclic AMP (cAMP)-dependent protein kinase A (PKA) enabled the corresponding gene to be characterized and the transcript to be identified in conidia and in PGT and AGT stage spores. cAMP-dependent PKA activity was detected in ungerminated conidia. These data suggest that PKA and cAMP are involved in conidial development. To substantiate this we exploited the responses of developing conidia to various surfaces, including exposure to the host leaf (fully inductive to AGT formation), cellulose membrane (semi-inductive), and glass (non-inductive). Assessment of fungal development, following application of exogenous cAMP or cAMP analogues, revealed that, at different concentrations and on different surfaces, cAMP either promoted or inhibited conidial differentiation. Various PKA inhibitors were tested for their effect on PKA activity and conidial development. A negative correlation was established between PKA inhibition in vitro and fungal development in vivo. Taken collectively, these data suggest that PKA and cAMP play a role in conidial differentiation in this obligate, plant-pathogenic fungus. |
| first_indexed | 2025-11-14T06:08:41Z |
| format | Journal Article |
| id | curtin-20.500.11937-5779 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:08:41Z |
| publishDate | 1999 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-57792017-09-13T16:04:15Z Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei Hall, A. Bindslev, L. Rouster, J. Rasmussen, S. Oliver, Richard Gurr, S. Erysiphe graminis f. sp. hordei, the causal agent of barley powdery mildew, is an obligate biotroph. On arrival on the host, a primary germ tube (PGT) emerges from the conidium. An appressorial germ tube (AGT) then appears, forms an appressorium, and effects host penetration. Such developmental precision may be due to multiple, plant-derived signals and to endogenous tactile and chemical signals. The transduction mechanism remains obscure. The isolation of an expressed sequence tag (EST) homologue of the catalytic subunit of cyclic AMP (cAMP)-dependent protein kinase A (PKA) enabled the corresponding gene to be characterized and the transcript to be identified in conidia and in PGT and AGT stage spores. cAMP-dependent PKA activity was detected in ungerminated conidia. These data suggest that PKA and cAMP are involved in conidial development. To substantiate this we exploited the responses of developing conidia to various surfaces, including exposure to the host leaf (fully inductive to AGT formation), cellulose membrane (semi-inductive), and glass (non-inductive). Assessment of fungal development, following application of exogenous cAMP or cAMP analogues, revealed that, at different concentrations and on different surfaces, cAMP either promoted or inhibited conidial differentiation. Various PKA inhibitors were tested for their effect on PKA activity and conidial development. A negative correlation was established between PKA inhibition in vitro and fungal development in vivo. Taken collectively, these data suggest that PKA and cAMP play a role in conidial differentiation in this obligate, plant-pathogenic fungus. 1999 Journal Article http://hdl.handle.net/20.500.11937/5779 10.1094/MPMI.1999.12.11.960 restricted |
| spellingShingle | Hall, A. Bindslev, L. Rouster, J. Rasmussen, S. Oliver, Richard Gurr, S. Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title | Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title_full | Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title_fullStr | Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title_full_unstemmed | Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title_short | Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordei |
| title_sort | involvement of camp and protein kinase a in conidial differentiation by erysiphe graminis f. sp. hordei |
| url | http://hdl.handle.net/20.500.11937/5779 |