An optimized Agrobacterium tumefaciens-mediated transformation system for random insertional mutagenesis in Fonsecaea monophora.

Chromoblastomycosis (CBM) is a chronic cutaneous or subcutaneous mycosis that is prevalent worldwide. Though CBM tends not to be fatal, it is difficult to treat and complications can include chronic, marked lesions, lymphatic damage, and neoplastic transformation. Fonsecaea monophora, as a new species segregated from Fonsecaea pedrosoi, is the predominant causative pathogen of CBM in southern China. However, research about F. monophora has been limited, which may be due to a lack of an effective genetic manipulation system for F. monophora. In this study, we successfully established a random insertional mutagenesis system by Agrobacterium tumefaciens-mediated transformation (ATMT) in F. monophora for the first time. In order to improve the efficiency of ATMT, various co-culture conditions were optimized, including: acetosyringone (AS) concentrations, co-culture duration, ratio of bacteria to conidia, and the A. tumefaciens strains. In addition, thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) was performed to identify the transferred DNA (T-DNA) flanking sequences of the F. monophora transformants. The valuable transformants obtained in this study will be used for research in the future.