Caracterização in silico e análise de uma sequência homóloga à sec14 em angiospermas

Abstract

Brazil is the world's largest producer of sugarcane. Although its importance, the molecular studies are difficult due to its genomic complexity, a high ploidy level. However, the discovery of new genes is important to improve field and sugar-alcohol industry. The aim of this work was to characterize a sugarcane homologous sequence PHOSPHATIDYLINOSITOLPHOSPHATIDYLCHOLINE TRANSFER PROTEIN SEC14 that has been identified in previous studies associated to the flowering process. The in silico characterization was performed by functional analysis of the gene, construction of protein-protein interaction networks, phylogeny, three-dimensional model and molecular dynamics and co-expression analysis. In addition, a RT-qPCR expression assay was performed in different plant tissues (leaves, roots or shoot apical meristem – SAM) as well drought stress, oxidative stress and calcium sulphate treatment. The results obtained using the bioinformatics tools showed the CRAL-TRIO domain presence in the same position, suggesting a conservation of the SEC14 sequence in plants. The phylogenetic analysis indicates probable duplications of the SEC14 protein in plants. The threedimensional model showed a structural conservation due to the presence of hydrophobic pocket for lipid binding, and it was confirmed by molecular dynamics. Furthermore, it was observed in sugarcane model another domain that was not known. Expression data revealed that SEC14 gene was differentially expressed SAM in the juvenile phase from early-flowering variety and in the adult phase from late-flowering variety. Moreover, comparing the expression in leaves and roots, it was observed a lower expression in leaves. The SEC14 expression had no significant difference in leaf tissues from plants submitted to drought and oxidative stress in growth room. Furthermore, it was analyzed the potential effect of calcium treatment in sugarcane plants in field condition. Moreover, it was not observed any expression difference in leaves or in SAM. Then, the data showed here provides a better understanding of how the SEC14 gene/protein may acts on sugarcane. This data revealed new knowledge about the 3D protein structure and it also brings new perspectives for molecular studies for crops such as sugarcane.