Integrative transcriptome and proteome analyses of Trichoderma longibrachiatum LC and its cellulase hyper-producing mutants generated by heavy ion mutagenesis reveal the key genes involved in cellulolytic enzymes regulation

Miaoyin Dong; Shuyang Wang; Fuqiang Xu; Guoqing Xiao; Jin Bai; Junkai Wang; Xisi Sun

doi:10.1186/s13068-022-02161-7

Integrative transcriptome and proteome analyses of Trichoderma longibrachiatum LC and its cellulase hyper-producing mutants generated by heavy ion mutagenesis reveal the key genes involved in cellulolytic enzymes regulation

Biotechnol Biofuels Bioprod. 2022 Jun 3;15(1):63. doi: 10.1186/s13068-022-02161-7.

Authors

Miaoyin Dong^{1

2}, Shuyang Wang^{3

4

5}, Fuqiang Xu^{1

2}, Guoqing Xiao^{6

7}, Jin Bai^{1

2}, Junkai Wang⁸, Xisi Sun^{1

2}

Affiliations

¹ Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China.
² University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China.
³ Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China. wangsy@impcas.ac.cn.
⁴ Institute of Biology, Gansu Academy of Sciences, 197 Dingxi South Rd, Lanzhou, 730000, Gansu, People's Republic of China. wangsy@impcas.ac.cn.
⁵ University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China. wangsy@impcas.ac.cn.
⁶ Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China. xiaogq@impcas.ac.cn.
⁷ University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China. xiaogq@impcas.ac.cn.
⁸ College of Physics and Electronic Engineering, Northwest Normal University, 967Anning East Rd, Lanzhou, 730000, Gansu, People's Republic of China.

Abstract

Background: The major challenge of facing the efficient utilization of biomass is the high cost of cellulolytic enzyme, while the Trichoderma longibrachiatum plays an essential role in the production of industrial enzymes and biomass recycling.

Results: The cellulase hyper‑producing mutants of LC-M4 and LC-M16 derived from the wild type T. longibrachiatum LC strain through heavy ion mutagenesis exhibited the high-efficiency secretion ability of cellulase and hemicellulose. The FPase activities of LC-M4 (4.51 IU/mL) and LC-M16 (4.16 IU/mL) mutants increased by 46.91% and 35.5% when compared to the LC strain, respectively. Moreover, these two cellulase hyper-producing mutants showed faster growth rate on the cellulosic substrates (Avicel and CMC-Na) plate than that of LC strain. Therefore, an integrative transcriptome and proteome profiling analysis of T. longibrachiatum LC and its cellulase hyper‑producing mutant LC-M4 and LC-M16 were employed to reveal the key genes involved in cellulolytic enzymes regulation. It was showed that the transcriptome and proteome profiles changed dramatically between the wild strain and mutant strains. Notably, the overlapped genes obtained from integrative analysis identified that the protein processing in ER involved in protein secretory pathway, starch and sucrose metabolism pathway and N-glycan biosynthesis pathway were significantly changed both in cellulase hyper-producing mutants and thereby improving the enzyme secretion efficiency, which maybe the main reason of cellulase hyper-production in LC-M4 and LC-M16 mutants. In addition, the three DEGs/DEPs (PDI, Sec61, VIP36) related with protein secretion in ER and two DEGs/DEPs (OST, MOGS) related with N-glycan biosynthesis were identified as key candidate genes participating in enzyme protein biosynthesis and secretion.

Conclusions: In this study, a hypothetical secretory model of cellulase protein in filamentous fungi was established on the basis of DEGs/DEPs and key genes identified from the omics analysis, which were of great guidance on the rational genetic engineering and/or breeding of filamentous fungi for improving cellulase production.

Keywords: Cellulase; Hyper-producing mutants; Proteomics; Transcriptomics; Trichoderma longibrachiatum.

Abstract

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