Full text
| |
| Author(s): |
Rafaela Rossi Rosolen
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2024-11-27 |
| Examining board members: |
Anete Pereira de Souza;
Luana Walravens Bergamo;
Lucas Miguel de Carvalho;
Roberto do Nascimento Silva;
Renato Graciano de Paula
|
| Advisor: | Anete Pereira de Souza; Maria Augusta Crivelente Horta |
| Abstract | |
The filamentous ascomycete fungus Trichoderma harzianum is widely recognized as an organism of considerable biotechnological importance due to its efficiency in producing and secreting carbohydrate-active enzymes (CAZymes). These enzymes have extensive industrial applications for the hydrolysis of plant biomass, promoting the production of biofuels and high-value bioproducts. The expression of the genes responsible for these hydrolytic enzymes is strictly regulated at the transcriptional level, with the transcription factors (TFs) XYR1 and CRE1 serving as the main regulators. This gene regulation is directly linked to the availability of carbon sources in the extracellular medium. Moreover, research has demonstrated that abiotic factors, including light, significantly influence the regulation of CAZyme genes through photoreceptors such as BLR1, BLR2, and ENV1. These photoreceptors interact with the heterotrimeric G protein and the cyclic AMP (cAMP) signaling pathway. In this context, genomic studies provide a more precise analysis of gene regulation in response to environmental variables such as light and carbon availability, linking a fungus’s phenotypic profile to its gene content. These studies are also fundamental for the bioprospecting of compounds with biotechnological interest. In this thesis, we (I) investigated, through gene coexpression networks, the gene regulation mediated by XYR1 and CRE1 during cellulose degradation in different strains of T. harzianum. We also (II) carried out the sequencing, assembly, gene prediction, and functional annotation steps of the genomes of T. harzianum IOC-3844 (Th3844) and T. harzianum CBMAI-0179 (Th0179), and for comparative purposes, Trichoderma reesei CBMAI-0711 (Tr0711) and Trichoderma atroviride (Ta0020), species that are phenotypically and phylogenetically distinct from T. harzianum. Finally, (III) we explored how light influences the regulation of genes associated with plant biomass degradation in the potentially hydrolytic strain Th3844. To this end, we analyzed the expression levels of genes encoding CAZymes, TFs, and proteins involved in the heterotrimeric G protein and cAMP signaling pathways under different light conditions and carbon sources. Overall, this study integrated bioinformatics and molecular biology to provide a deeper understanding of how specific gene sets in T. harzianum respond to different environmental stimuli and how this species' genome is organized and adapted to optimize its ability to degrade lignocellulosic materials and survive in variable conditions. The results of this thesis not only expand our knowledge of the biology and ecology of this species but also present significant practical implications for optimizing industrial processes, such as biomass degradation and the production of metabolites of interest (AU) | |
| FAPESP's process: | 20/13420-1 - Evaluation of the influence of the light on the expression of hydrolytic enzymes for the bioprospecting of fungi of the genus Trichoderma with hydrolytic potential |
| Grantee: | Rafaela Rossi Rosolen |
| Support Opportunities: | Scholarships in Brazil - Doctorate |