Properties analysis of transcription factor gene TasMYB36 from Trichoderma asperellum CBS433.97 and its heterogeneous transfomation to improve antifungal ability of Populus.

The transcription of TasMYB36 in the biocontrol species T. asperellum was upregulated in four different pathogenic fermentation broths, suggesting that TasMYB36 plays an important role in the response to biotic stresses. Seventy-nine MYB transcription factors that were homologous to TasMYB36 from six sequenced Trichoderma genomes were analyzed. They were distributed in fourteen clades in the phylogenetic tree. The 79 MYBs contained 113 DNA binding domains, and their amino acid sequences were conserved and were different to those in plants. The promoters of 79 MYBs contained 1374 cis-regulators related to the stress response, such as GCR1 (17.5%) and GCN4 (15.5%). Subsequently, TasMYB36 was integrated into the genome of Populus davidiana × P. alba var. pyramidalis (PdPap poplar), and after co-culture of the transformants (PdPap-TasMYB36s) with Alternaria alternate, the transcription of genes in the jasmonic acid (JA) and salicylic acid (SA) hormone signaling pathways were upregulated; the POD, SOD and CAT activities were enhanced; and the reactive oxygen content was reduced in PdPap-TasMYB36s. The disease spots area on PdPap-TasMYB36s leaves infected by A. alternate were average 0.63% (PdPap-Con: 24.7%). In summary, TasMYB36 of T. asperellum CBS433.97 is an important defense response gene that upregulates other stress response genes and could improve resistance to biotic stresses.