Proteomic and mechanistic analysis of Auxin Response Factors in the Arabidopsis embryo

Auxin is a phytohormone that is crucial for many aspects of plant development. The processes in which this hormone has been implicated span from embryo development to flower transition, defense, tropic responses, and many other processes during plant life. A key question in auxin biology is how this molecule is able to elicit such diverse responses. Auxin regulates the transcriptional activation or repression of genes through the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. In my studies I focus in the ARF transcription factors as a likely source of variation in output specificity. We consider three levels at which ARFs differ. First, ARFs differ in their ability to interact with different Aux/IAA (antagonistic family of transcription factors), or to form homo- or heterodimers. Second, ARFs assemble into different protein complexes, transcription factors interact with other transcriptional regulators or other proteins to form transcription complexes. These, when different, may contribute to different functions of ARF complexes. Thirdly, ARFs bind to and regulate different target genes. My work offers a plausible explanation how specific auxin responses are generated and through which genes the developmental responses to auxin are generated.