Plant ferredoxin-like protein (PFLP) exhibits an anti-microbial ability against soft-rot pathogen Erwinia carotovora subsp. carotovora in vitro and in vivo

The anti-microbial protein was frequently used to control the plant bacterial disease. In this study, it was investigated that the anti-microbial activity of recombinant plant ferredoxin-like protein (PFLP) both in vitro and in vivo. The in vitro assay demonstrated that PFLP produced by transformed Escherichia coli exhibited an anti-microbial activity against several bacteria strain including E. coli, Erwiniacarotovora and Pseudomonas syringae. The effectiveness of this anti-microbial activity was depending on the FeSO4 that was applied in the cultivated medium. PFLP lost its anti-microbial activity when it was mutated in the 86th cysteine residue that responding for iron binding. Besides, soft-rot symptom of tobacco plants infected by E. carotovora was reduced by application of recombinant PFLP. Transgenic tobacco ectopically over expressing PFLP in the cytoplasm protected plant from the infection of E. carotovora during the initial stage. These results indicate that PFLP is an anti-microbial protein that might be able to control the plant diseases via reducing the growth of bacterial pathogen.