Involvement of a dihydrodipicolinate synthase gene (FaDHDPS1) in fungal development, pathogenesis and stress responses in Fusarium asiaticum.

BACKGROUND

Dihydrodipicolinate synthase (DHDPS) is an allosteric enzyme, which catalyzes the first unique step of lysine biosynthesis in prokaryotes, higher plants and some fungi. To date, the biological roles of DHDPS in filamentous fungi are poorly understood.

RESULTS

In this study, on the basis of comparative genome resequencing, a DHDPS gene was found to be specific in Fusarium asiaticum, named FaDHDPS1, which showed high amino acid identity to that of entomopathogenic fungus. Subcellular localization of the FaDHDPS1-GFP fusion protein was mainly concentrated in the cytoplasm of conidia and dispersed in the cytoplasm during conidial germination. To reveal the biological functions, both deletion and complementation mutants of FaDHDPS1 were generated. The results showed that the FaDHDPS1 deletion mutant was defective in conidiation, virulence and DON biosynthesis. In addition, deletion of FaDHDPS1 resulted in tolerance to sodium pyruvate, lysine, low temperature and Congo red.

CONCLUSION

Results of this study indicate that FaDHDPS1 plays an important role in the regulation of vegetative differentiation, pathogenesis and adaption to multiple stresses in F. asiaticum.