Solanum tuberosum Aux/IAA family: new members and characterization of StIAA1 interacting proteins

Abstract

Auxin/indole-3-acetic acid (Aux/IAA) proteins are transcriptional repressors that regulate auxin-mediated gene expression by interacting with members of the auxin response factor (ARF) family. We previously identified the first Solanum tuberosum Aux/IAA member, StIAA1, as a stress-responsive gene. In this report, we described that StIAA1 interacts with TIR1 auxin receptor suggesting a conserved participation in auxin signaling pathway. In addition, protein–protein interaction between StIAA1 and new members of S. tuberosum Aux/IAA (StIAA3 and StIAA4) and ARF (StARF1) families was demonstrated. Furthermore, thirteen other members of the S. tuberosum Aux/IAA family were identified by in silico analysis. This overall view of auxin signaling components in a Solanaceae contributes to enrich the understanding of this hormonal pathway in other plants phylogenetically distant from A. thaliana.