Effect Of Small RNA On The Expression Of Cellulase In Trichoderma Reesei And Its Transcriptome Analysis

Trichoderma reesei(teleomorph Hypocrea jecorina) is widely used in industry as a source of cellulase and hemicellulase. T. reesei has excellent ability of protein synthesis and secretion. Small non-coding RNAs generally exist in eukaryotes, and they have function of regulating gene expression. In recent years, researchers have found a variety of small RNAs in fungi, such as qi RNAs and mil RNAs( micro RNA like RNAs) in Neurospora crassa and T.reesei.In the first half of this study, the regulation function of small non-coding RNAs on cellulase expression in T. reesei QM9414 was studied through over-expression of the small RNAs with over-expression cassettes and inhibition of the small RNAs with Tough Decoy(Tu D) technology. Then the cellulase production efficiency in the recombinant strains was analyzed. The result of RT-PCR(Real Time PCR) analysis showed that the over-expression cassette enhanced the expression of the small RNAs, and the Tu D sequence inhibited the function of the small RNAs, respectively. In addition, the analysis of the cellulase production in the recombinant strains indicated that one of the small RNAs, mil R7, might participate in the regulation of cellulase expression.Although the cellulase expression of T. reesei can be improved by gene overexpression, gene knockout and so on, but our understanding of T. reesei is still insufficiency. Comprehensive understanding of T. reesei could further explore the potential of its excellent biological functions and help improve cellulase production. In the second half of this work, the cellulose induction(Trind) and non-induction(Trcond) transcriptomes of T. reesei were characterized using high-throughput sequencing on the Illumina sequencing platform. As a result, we identified the transcripts involved in the regulation of cellulase expression, and found 8 genes might associate with the regulation of cellulase expression in T. reesei.This study found that small RNA-mil R7 could significantly improve cellulase activity, and found 8 genes might participate in the regulation of cellulase expression. This work represents a valuable resource for genomic studies and demonstrates a new strategy and approach for increasing cellulase activities in T. reesei.