Recognition of a core fragment ofBeauveria bassiana hydrophobin gene promoter (P hyd1) and its special use in improving fungal biocontrol potential.
Bottom Line: Further truncating P hyd1-t1 to 1179, 991 and 791 bp or mutating one of the binding domains of three transcription factors in P hyd1-t1 reduced significantly the expression of eGFP (enhanced green fluorescence protein).Therefore, P hyd1-t1 was used to integrate a bacterium-derived, insect midgut-specific toxin (vip3Aa1) gene into B. bassiana, yielding a transgenic strain (BbHV8) expressing 9.8-fold more toxin molecules in conidia than a counterpart strain (BbV28) expressing the toxin under the control of P gpdA, a promoter widely used for gene expression in fungi.Conclusively, P hyd1-t1 is a useful tool for enhancing beneficial protein expression, such as vip3Aa1, in fungal conidia, which are the active ingredients of mycoinsecticides.
Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.Show MeSH
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Mentions: Interestingly, the eGFP expression under Phyd1-t1 control was barely detected during the first 48 h of incubation of selected transformants on Sabouraud dextrose agar plus yeast extract (SDAY) at 25°C but rapidly increased following this time period. The eGFP-emitted fluorescence under laser confocal microscope was much more intense in conidiogenic cells and conidia than in younger mycelia (Fig. 2b). Mean RFI in the colonies increased from 2.4 on day 2 to 1187 on day 4 and reached a peak of 1842 on day 7 (Fig. 2c), when conidiation was completed. These data indicated that Phyd1-t1 enabled the activation of gene expression specifically during the conidiophore development and conidiation of B. bassiana.
Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.