| Congresso Brasileiro de Microbiologia 2023 | Resumo: 469-1 | ||||
Resumo:With the increase in world demand for ethanol, the use of lignocellulosic biomass as an alternative to produce it has become necessary. The degradation of lignocellulose polysaccharides is a process that requires enzymes, called cellulases, which act cooperatively to degrade it into soluble sugars. The filamentous fungus Trichoderma reesei exhibits an amazing ability to produce and secrete cellulases. Thus, the understanding of the molecular mechanisms and nutrient sensing related to the process of deconstruction of lignocellulosic biomass in T. reesei, through the involvement of proteins with CFEM domain (Common in several fungal extracellular membrane) of the cell signaling pathways associated with this process is of paramount importance. In this context, the objective was to understand the role of cell receptors with CFEM domain in cell signaling processes and in the regulation of cellulase gene expression. Through RNA-seq., T. reesei data grown in sugarcane bagasse (SCB), previously obtained by our research group, eight genes containing receptors with CFEM domain were differentially expressed: Tr_104401, Tr_102837, Tr_124295, Tr_122941, Tr_123039, Tr_111205, Tr_105763 and Tr_70840. Next, we analyzed the expression of these genes in T. reesei RNA-Seq data cultured in the presence of cellulose, sophorose and glucose and only the genes Tr_122941, Tr_111205, Tr_102837 and Tr_104401 showed significant levels of expression. Thus, at first, the expression profile of the genes that code for CFEM proteins was analyzed when the parent strain QM6a was grown for up to 72 h in glucose, cellulose and SCB. The expression of Tr_111205 in the different carbon sources was significantly higher compared to the other genes that code for the receptors with CFEM domain. In addition, the expression of the Tr_111205 gene was quite expressive in the first hours of cultivation of the QM6a strain in cellulose and remained until the final time of 72 h. In SCB, the expression profile of the genes of the receptors with CFEM domain were analyzed at the times of 1 h, 4 h, 8 h, 12 h, 24 h, 48 h and 72 h. The Tr_122941 gene exhibited higher values of expression levels in the first hours of T. reesei cultivation in SCB. Regarding genes Tr_102837 and Tr_104401 low expression levels were observed in the presence of glucose, cellulose and SCB. Thus, the expression results suggest that among the genes analyzed, Tr_122941 and Tr_111205 may play an important role in T. reesei signaling pathways and in the recognition of nutrients such as glucose, cellulose and SCB. Thus, the construction of mutant strains for these two genes will allow a greater understanding of the receptors with CFEM domain during biomass degradation by T. reesei, in addition to a high production capacity of cellulolytic enzymes, since during the process of induction of cellulase expression occurs specific modulation in the composition of receptors on the cell membrane of T. reesei to respond adequately to the different carbon sources. Palavras-chave: cellulases, Trichoderma reesei, gene expression, CFEM domain Agência de fomento:FAPESP - São Paulo Research Foundation (20/08381-7), Capes e CNPq | |||||