Cloning and expression of the osmotic tolerance gene Bbmpd of Beauveria bassiana

Abstract:

Abstact: [Objective] We isolate the gene involved in osmotolerance of Beauveria bassiana for investigation the adaptation mechanism of the fungus to adversity. [Methods] T-DNA tagging and genomic DNA walking were carried out by using Y-shaped adaptor dependent extension (YADE) method. RT-PCR was used to analyze the transcription profile of Bbmpd. [Results] A gene (Bbmpd) encoding mannitol 1-phosphate dehydrogenase in B. bassiana was identified. The transcription of Bbmpd was induced by osmostress (0.8 mol/L NaCl) in wild type strain, while significantly decreased in Bbhog1 mutant, indicating that the transcription of Bbmpd was regulated by Hog1 pathway in B. bassiana. Bbmpd-disrupted mutants showed sensitive to osmostress on Czapek’s medium containing 0.8 mol/L NaCl. However, the growth and sporulation of the Bbmpd-disrupted mutants in vitro were not significantly different from that of wild type strain. [Conclusion] Mannitol 1-phosphate dehydrogenase gene was isolated by T-DNA tagging, and was found to be involved in the osmostress of B. bassiana. The transcription of Bbmpd was induced by osmostress and regulated by Hog1 pathway.