Growth, Enzymatic, and Transcriptomic Analysis of <i>xyr1</i> Deletion Reveals a Major Regulator of Plant Biomass-Degrading Enzymes in <i>Trichoderma harzianum</i>
Lunji Wang,
Yishen Zhao,
Siqiao Chen,
Xian Wen,
Wilfred Mabeche Anjago,
Tianchi Tian,
Yajuan Chen,
Jinfeng Zhang,
Sheng Deng,
Min Jiu,
Pengxiao Fu,
Dongmei Zhou,
Irina S. Druzhinina,
Lihui Wei,
Paul Daly
Affiliations
Lunji Wang
College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China
Yishen Zhao
College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China
Siqiao Chen
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Xian Wen
College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China
Wilfred Mabeche Anjago
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Tianchi Tian
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Yajuan Chen
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Jinfeng Zhang
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Sheng Deng
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Min Jiu
College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China
Pengxiao Fu
Jiangsu Coastal Ecological Science and Technology Development Co., Ltd., Nanjing 210036, China
Dongmei Zhou
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Irina S. Druzhinina
Department of Accelerated Taxonomy, The Royal Botanic Gardens Kew, London TW9 3AE, UK
Lihui Wei
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Paul Daly
Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed through growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~90% lower β-glucosidase activity, and no detectable β-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. The expression of a subset of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes.
