Dos Santos Castro Lilian, de Paula Renato G, Antoniêto Amanda C C, Persinoti Gabriela F, Silva-Rocha Rafael, Silva Roberto N
Molecular Biotechnology Laboratory, Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil.
Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais Campinas, Brazil.
Front Microbiol. 2016 Feb 16;7:175. doi: 10.3389/fmicb.2016.00175. eCollection 2016.
We defined the role of the transcriptional factor-XYR1-in the filamentous fungus Trichoderma reesei during cellulosic material degradation. In this regard, we performed a global transcriptome analysis using RNA-Seq of the Δxyr1 mutant strain of T. reesei compared with the parental strain QM9414 grown in the presence of cellulose, sophorose, and glucose as sole carbon sources. We found that 5885 genes were expressed differentially under the three tested carbon sources. Of these, 322 genes were upregulated in the presence of cellulose, while 367 and 188 were upregulated in sophorose and glucose, respectively. With respect to genes under the direct regulation of XYR1, 30 and 33 are exclusive to cellulose and sophorose, respectively. The most modulated genes in the Δxyr1 belong to Carbohydrate-Active Enzymes (CAZymes), transcription factors, and transporters families. Moreover, we highlight the downregulation of transporters belonging to the MFS and ABC transporter families. Of these, MFS members were mostly downregulated in the presence of cellulose. In sophorose and glucose, the expression of these transporters was mainly upregulated. Our results revealed that MFS and ABC transporters could be new players in cellulose degradation and their role was shown to be carbon source-dependent. Our findings contribute to a better understanding of the regulatory mechanisms of XYR1 to control cellulase gene expression in T. reesei in the presence of cellulosic material, thereby potentially enhancing its application in several biotechnology fields.
我们确定了转录因子XYR1在丝状真菌里氏木霉降解纤维素材料过程中的作用。在这方面，我们使用RNA测序对里氏木霉Δxyr1突变菌株进行了全转录组分析，并将其与在纤维素、槐糖和葡萄糖作为唯一碳源的条件下生长的亲本菌株QM9414进行比较。我们发现，在三种测试碳源下，有5885个基因表达存在差异。其中，322个基因在纤维素存在时上调，而在槐糖和葡萄糖存在时分别有367个和188个基因上调。关于受XYR1直接调控的基因，分别有30个和33个基因仅在纤维素和槐糖存在时表达。Δxyr1中调控最明显的基因属于碳水化合物活性酶（CAZyme）、转录因子和转运蛋白家族。此外，我们强调了属于主要易化子超家族（MFS）和ABC转运蛋白家族的转运蛋白的下调。其中，MFS成员在纤维素存在时大多下调。在槐糖和葡萄糖中，这些转运蛋白的表达主要上调。我们的结果表明，MFS和ABC转运蛋白可能是纤维素降解中的新参与者，并且它们的作用显示出碳源依赖性。我们的发现有助于更好地理解XYR1在纤维素材料存在时控制里氏木霉纤维素酶基因表达的调控机制，从而有可能增强其在多个生物技术领域的应用。
