Katrin Heidemeyer: Mechanisms of ARF Functionality

Auxin is an important regulator of the major processes that take place throughout plant life. This signaling molecule acts in the nucleus to control a family of DNA-binding transcriptional regulators; the AUXIN RESPONSE FACTORS (ARF). Some members of the ARF family have been studied extensively and can be linked to severe phenotypic effects in loss-of-function mutants. Yet, not much is known about the remaining transcription factors, for which single mutant plants do not show severe phenotypes (Weijers and Wagner 2016). This, however, indicates functional redundancy of a number of ARF proteins and therefore, I am interested in gaining a better understanding of the developmental function and mechanisms of action of these ARFs. In order to analyze the biological function, I will characterize double- and triple mutants (generated by genome editing) and identify target genes. In addition, I will investigate how the ARFs carry out their function. To do so I want to analyze their DNA binding behavior, requirement for dimerization and interaction partners. Finally, promoter swap analysis between species will reveal whether Arabidopsis ARFs have retained their function through out evolution. This research will help gaining more understanding on the evolution of auxin signaling.

Weijers D. and Wagner D., Annu. Rev. Plant Biol. (2016), 67:539-74