Functions of peptide pheromones beyond sexual development in Hypocrea jecorina with an emphasis on cellulase gene expression

02.07.2007 - 31.03.2011
Research funding project
Species of fungal genus Trichoderma are saprophytes, and their respective teleomorphs lignicolous and necrotrophic ascomycetes of the genus Hypocrea. Hypocrea jecorina (the teleomorph of Trichoderma reesei), is probably the most prominent cellulose degrader within the genus Trichoderma. Apart from studies on the enzymology of cellulose degradation, there has also been a continuing interest in understanding how the synthesis of these enzymes is regulated. It is generally believed that oligosaccharides, which are released from cellulose, serve as the actual compounds triggering the high level of induction of cellulase expression. However, only little is known about how these environmental stimuli launch the signal transduction cascade finally leading to enhanced transcription of the cellulase genes and which components are involved in this cascade. Recently, the involvement of the light regulatory protein Envoy in cellulase regulation was reported, thus establishing a link between cellulose signalling and light response. Also the finding that the G-alpha proteins GNA1 and GNA3 influence cellulase gene transcription in dependence of light points into this direction. Studies on genes putatively involved in cellulase signalling further showed that H. jecorina possesses an unusual a-factor pheromone, which is involved in light-dependent cellulase gene transcription. Since signal transduction via heterotrimeric G-proteins is involved in pheromone signalling and also because of the links between cellulose- and pheromone signalling as well as light response as suggested by our own studies we intend to elucidate the interconnection of these pathways and to amend our first sketch of this signal transduction network in H. jecorina. Therefore we want to investigate the effect of the two peptide pheromone precursor genes min1 and ppg1 on cellulase gene expression by gene deletion, overexpression of these genes in light and darkness. Also the influence of the light regulatory gene env1 on this signaling cascade as well as the impact to the regulatory pathway including both light response and pheromone expression/response on the known cellulase regulators ACE1, ACE2 and XYR1 shall be studied.

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Institute

Grant funds

  • FWF - Österr. Wissenschaftsfonds (National) Austrian Science Fund (FWF)

Research focus

  • Biological and Bioactive Materials: 100%

Keywords

GermanEnglish
Hypocrea jecorinaHypocrea jecorina
Pheromonepeptide pheromones
Cellulasencellulases

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