Identificação e caracterização das famílias de gene de catalase, superóxido dismutase (SOD) e peroxidase de Manihot esculenta Crantz.

Abstract

Cassava (Manihot esculenta Crantz) is a perennial plant, i.e. it presents an indefinite growth, changing its vegetative growth periods, storing carbohydrate in the roots is usually grown by small producers as a subsistence crop because of its tolerance to poor soils and adverse climatic conditions, being planted in various production systems with this presenting great socioeconomic importance in Brazil. However, its production can suffer economic losses when the plant is exposed to pathogens. In this context, plants in response to biotic stress resort to genes involved in such signals, as the Catalase, Superoxide dismutase and Peroxidase gene that constitute antioxidant enzymes. Therefore, this study aims to identify and characterize in silico, gene families of Catalase (MeCAT), Superoxide dismutase (MeSD) and glutathione peroxidase (MePOD), in cassava. For the methodology of the work used the DNA and protein sequences obtained in the Phytosome program by searching for the name of the enzymes and the plant species. Regarding the similarity with proteins of other plant species deposited in the databases, the BLAST tool was used. Subsequently, the alignment of nucleotide and amino acid sequences was performed with the aid of the program CLUSTALW using the standard parameters. The programs SignalP v.2.0 and Web Phobius prediction were used to identify if there is signal peptide in the protein sequences of the genes of the three enzymes, these tools were then fundamental for the characterization of the gene. Then, the subcellular localization was obtained using SherLoc2 and the Y Loc system. Phylogenetic analysis was performed using the Molecular Evolutionly Genetics Analysis software, using the Neighbor-Joining method. The results obtained show that catalase gene family in Manihot esculenta has 7 isoforms, that of superoxide dismutase contains 9 and that of glutathione peroxidase 15. Regarding subcellular localization of catalase is in the cytoplasm, of superoxide dismutase is diversified within the plant cell and that of glutathione peroxidase mainly in the secreted pathway of the cell and have other necessary features to be considered from these families.