Osmotic-Adaptation Response of sakA/hogA Gene to Aflatoxin Biosynthesis, Morphology Development and Pathogenicity in Aspergillus flavus.

s is one of the fungi from the big family of genus and it is capable of colonizing a large number of seed/crops and living organisms such as animals and human beings. (also called ) is an integral part of the mitogen activated protein kinase signal of the high osmolarity glycerol pathway. In this study, the gene was deleted () then complemented (∆) using homologous recombination and the osmotic stress was induced by 1.2 mol/L D-sorbital and 1.2 mol/L sodium chloride. The result showed that ∆ mutant caused a significant influence on conidial formation compared to wild-type and ∆ strains It was also found that responds to both the osmotic stress and the cell wall stress. In the absence of osmotic stress, ∆ mutant produced more sclerotia in contrast to other strains, whereas all strains failed to generate sclerotia under osmotic stress. Furthermore, the deletion of resulted in the increase of Aflatoxin B₁ production compared to other strains. The virulence assay on both maize kernel and peanut seeds showed that ∆ strain drastically produced more conidia and Aflatoxin B₁ than wild-type and complementary strains. AfSakA-mCherry was located to the cytoplasm in the absence of osmotic stress, while it translocated to the nucleus upon exposure to the osmotic stimuli. This study provides new insights on the development and evaluation of aflatoxin biosynthesis and also provides better understanding on how to prevent infections which would be considered the first step towards the prevention of the seeds damages caused by .