Genetic regulation of conidiation in Trichoderma hamatum
Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial bio...
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| Format: | Article |
| Language: | English |
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Zhejiang University Press
2004-07-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
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| Online Access: | https://www.academax.com/doi/10.3785/1008-9209.2004.04.0442 |
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| author | Johanna Steyaert Travis Glare Alison Stewart Margaret Carpenter Hayley Ridgway |
| author_facet | Johanna Steyaert Travis Glare Alison Stewart Margaret Carpenter Hayley Ridgway |
| author_sort | Johanna Steyaert |
| collection | DOAJ |
| description | Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride. These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response. Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1, which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting comparable stage-specific RNA from T. hamatum and T. atroviride. Using degenerate PCR putative sporulation gene orthologues have also been identified in T. hamatum. Work is currently underway to isolate genomic clones of these genes from T. hamatum and T. atroviride. Sequence and expression analysis of orthologues, including expression in response to abiotic factors will be presented and discussed in relation to the current knowledge of the molecular basis of conidiation in Trichoderma and other filamentous fungi. |
| format | Article |
| id | doaj-art-dd0987b2eb494a4ca1fa8fd4c61feb14 |
| institution | Kabale University |
| issn | 1008-9209 2097-5155 |
| language | English |
| publishDate | 2004-07-01 |
| publisher | Zhejiang University Press |
| record_format | Article |
| series | 浙江大学学报. 农业与生命科学版 |
| spelling | doaj-art-dd0987b2eb494a4ca1fa8fd4c61feb142025-08-20T03:33:22ZengZhejiang University Press浙江大学学报. 农业与生命科学版1008-92092097-51552004-07-013044244210.3785/1008-9209.2004.04.044210089209Genetic regulation of conidiation in Trichoderma hamatumJohanna SteyaertTravis GlareAlison StewartMargaret CarpenterHayley RidgwayAchieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride. These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response. Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1, which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting comparable stage-specific RNA from T. hamatum and T. atroviride. Using degenerate PCR putative sporulation gene orthologues have also been identified in T. hamatum. Work is currently underway to isolate genomic clones of these genes from T. hamatum and T. atroviride. Sequence and expression analysis of orthologues, including expression in response to abiotic factors will be presented and discussed in relation to the current knowledge of the molecular basis of conidiation in Trichoderma and other filamentous fungi.https://www.academax.com/doi/10.3785/1008-9209.2004.04.0442conidiationgene regulation<italic>Trichoderma atroviride</italic><italic>Trichoderma hamatum</italic> |
| spellingShingle | Johanna Steyaert Travis Glare Alison Stewart Margaret Carpenter Hayley Ridgway Genetic regulation of conidiation in Trichoderma hamatum 浙江大学学报. 农业与生命科学版 conidiation gene regulation <italic>Trichoderma atroviride</italic> <italic>Trichoderma hamatum</italic> |
| title | Genetic regulation of conidiation in Trichoderma hamatum |
| title_full | Genetic regulation of conidiation in Trichoderma hamatum |
| title_fullStr | Genetic regulation of conidiation in Trichoderma hamatum |
| title_full_unstemmed | Genetic regulation of conidiation in Trichoderma hamatum |
| title_short | Genetic regulation of conidiation in Trichoderma hamatum |
| title_sort | genetic regulation of conidiation in trichoderma hamatum |
| topic | conidiation gene regulation <italic>Trichoderma atroviride</italic> <italic>Trichoderma hamatum</italic> |
| url | https://www.academax.com/doi/10.3785/1008-9209.2004.04.0442 |
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