Biochemical and Genetic Responses of Fungi to the Toxic Effect of Synthetic and Natural Fungicides

The objective of the present review is to analyze the molecular basis of fungicide resistance mechanism to both synthetic fungicides and the natural fungicides isothiocyanates. The review is focused mainly on Alternaria sp., but whenever available, similar studies in other fungi have been included. Fungal resistant strains to dicarboximide and phenylpyrrole fungicides have been found to contain mutations in one of the proteins involved in the signal transduction pathway that regulates the fungal response to osmotic stress. By the other hand, it was found that isothiocyanates induce enzymes like glutathione S-transferase, cyanide hydratase, heat shock proteins, membrane transporters and proteins associated with the oxidative stress response. Also, inter simple sequence repeats polymorphism was recorded as a response to the isothiocyanates treatment. The knowledge about the genetic basis of the response mechanism of Alternaria sp. to the isothiocyanates is scarce. Therefore, studies by DNA recombinant technology to analyze the fungi responses to fungicides, will allow knowing the metabolic pathways involved in the phenomena to permit the design of strategies to inhibit key reactions involved in the fungal resistance, reaching a better and sustainable fungal infections control.