Caracterização interação molecular da proteína reprimida por auxina em resposta ao controle de desenvolvimento de tomateiro

Abstract

Flowering is an important process for the plants and it corresponds to the apical meristem transition from the vegetative to the reproductive phase. Previous data from our laboratory using subtractive libraries identified a sequence that had homology to AUXIN REPRESS PROTEIN (ARP). This protein has been identified in other species but it is now clear which its function in plants is. Then, T the aim of this work was to understand the role of ARP protein in tomato and in flowering transition. First, it was done a sequence alignment using 13 protein sequences and omega clustal. In this alignment it was observed that the tomato ARP protein had the four domains that were characteristic from this family. The domain I is a leucine-rich motif, which has an amphiphilic repression region at its N-terminus. Domain II that contains an internal motif core composed of glycine, tryptophan and proline. Furthermore, at the C-terminal region, there are the domain III and IV, which together form the PB1 domain (Phox / Bem1p). This domain has a typical lysine and a series of acid residues. Using the STRING 10.0 database (http://www.string-dg.org) with a confidence index of 0.7, it was observed an interaction network where ARP1 protein interacts with more than 21 different proteins. The proteins CBS, Myf5, APE1 and GRX1 proteins, directly interact to ARP1 protein in this network. Moreover, these proteins are also expressed in tomato reproductive tissues as it was observed using the eFPBar tool (http://bar.utoronto.ca/efp_tomato/cgi -bin/efpWeb.cgi). In addition, using two hybrids tool, it was observed eight different protein-protein interactions in vivo. Three of these sequences codify two putative proteases and the third codify the CYTOCHROME C-OXIDASE protein. These proteins may be associated to cell energy metabolism. The other five sequences identified codify the PHYTOEN SYNTHASE protein. In order to better understand the possible role of ARP1 protein, then, it was used the Cytoscape 3.7.2 program in order to make an interactome network using the in silico and in vivo data. It was possible to identify the presence of five clusters, which are associated to plant energy metabolism, growth mechanism and cell differentiation. Moreover, it was evaluated the auxin levels in transgenic plants having the overexpression cassette in sense and antisense orientation. In addition, it was observed that transgenic plants having the antisense cassette had lower auxin levels. Considering this data and the interactome, it may proposed a role in plant development and flowering transition for the ARP1 protein.