Filogenia molecular de espécies da família Myrtaceae e análises in silico da proteína 1-aminociclopropano-1-carboxilato sintase em representantes de dicotiledôneas

Abstract

The Myrtaceae family is of great economic and ecological importance in Brazil. Several representatives of the family, especially the Eucalyptus genus, are of great importance in the production of wood for industrial use, and fruits of species from the Myrteae tribe such as guava, pitanga, araçá and jaboticaba, are used for food production, whether in natura or industrialized. With the evolution of DNA sequencing tools, several methodologies to establish evolutionary correlations between the species of this family, such as molecular markers, have been used together with morphological data. Due to its characteristic of low mutation rate, the chloroplast genome has markers that can be used for phylogenetic inferences. Important protein transcripts can also be tools for establishing correlations between species since they start from the same principle of low mutation rate so that their function in organisms is not lost. In order to perform a comparative analysis between plasmas of species of Myrtaceae, perform a phylogenetic reconstruction of species of the Myrtaceae family, and perform phylogenetic analysis based on four plastidial genes for the order Myrtales, complete plastome and gene sequences of species of the Myrtaceae family were obtained in FASTA format from the GenBank database. Phylogenetic reconstruction and sequence alignment were performed using the MEGA7 software. To reconstruct the phylogenetic hypotheses, the maximum likelihood method with a bootstrap of 1000 was used for all analyzes. Phylogenetic correlations for the Myrtaceae family resulted in a monophyletic tree with strongly supported clades, with low bootstrap values for the relationships between species of the Eucalipteae tribe. The phylogeny of the Myrtales order resulted in paraphyletism among some families also with strong supported clades. It is concluded that these correlations obtained for both the Myrtaceae family and for the order Myrtales are similar to the correlations performed with morphological markers, confirming the reliability of plastidial genes for phylogenetic studies. The sequences of the 1-aminocyclopropane-1-carboxylate synthase proteins were retrieved from the GenBank database using the BlastP tool. The physical-chemical parameters were evaluated using the ProtParam tool. The identification of functional domains was evaluated using the Prodom server and the mutational effects were estimated using the SNAP2 server. The protein sequence alignment was performed using the ClustalW algorithm and the phylogenetic trees produced with the MEGA 7 software using the maximum likelihood method. To predict the structure of proteins in 3D models, the Phyre2 server was used. Phylogenetic trees of dicotyledonous species built using the ACC synthase protein sequence are consistent with the classification proposal presented in the literature. However, the methods used proved to be sufficient for separation up to the tribe level within the Malvaceae, Rutaceae, Euphorbiaceae, Vitaceae, Moraceae, Cannabaceae, Solanaceae, Compositae, Myrtaceae, Juglandaceae, Fagaceae, Rosaceae and Leguminosae families. The use of in silico tools proved to be feasible for building a 3D model of proteins through homology modeling. The generated 3D models demonstrated stability in terms of energy level, enabling the analysis of their tertiary structures and molecular functions.