ABSTRACT
Objective: To clone the Bax inhibitor-1 (BI-1) gene from Polyporus umbellatus and perform the bioinformatics and expression mode analysis. Methods: To clone the full-length cDNA of BI-1 using RACE technology. The characteristics of physiochemical properties, conserved domains, and transmembrane domain of the predicted BI-1 protein were determined using bioinformatic tools. Results: The full-length cDNA of BI-1 gene was 1 091 bp in length and encoded a 334-aa protein with a molecular weight of 36170 and an isoelectric point (pI) of 10.51. The polypeptide chain was a hydrophobin with five hydrophobic regions. The PuBI-1 belonged to basidiomycete group according to the phylogenetic analysis. Real time quantitative PCR (RT-qPCR) analysis revealed that the transcription level of PuBI-1 gene was significantly higher in the beginning and developing stages of sclerotial formation with 3.8 and 7.497 fold over those in the mycelium, but the transcripts decreased sharply with the sclerotial development. Conclusion: Molecular characterization and expression patten of PuBI-1 gene will be useful for the further functional determination of the gene during the development of P. umbellatus sclerotium.