Functions of Auxin Response Factors

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

0116106 Reed The plant hormone auxin controls multiple developmental processes including elongation of stems, branching of shoots and roots, bending toward or away from light or gravity, and patterning of various tissues. Auxin Response Factors (ARFs) are a family transcription factors that regulate induction and repression of genes in response to auxin, and therefore have key functions in mediating these developmental processes. This project will focus on functions and interactions of ARF6 and ARF8, two ARFs in the model plant Arabidopsis thaliana that activate genes in response to auxin. The aims of the project are i) to discover developmental functions of these two transcription factors by characterizing phenotypes of arf6 and arf8 mutant plants and of transgenic plants that overexpress epitope-tagged ARF6 or ARF8; ii) to identify genes that ARF6 and ARF8 regulate by hybridizing probes made from untreated or auxin-treated wild-type and mutant plants to gene chips containing DNA representing thousands of Arabidopsis genes; iii) to explore functional interactions between ARF6 and ARF8 and selected proteins of the related Aux/IAA family, by constructing double mutants between arf6 and arf8 and selected mutations in IAA genes and examining their phenotypes; iv) to raise ARF6- and ARF8-specific anti-peptide antibodies; and v) to use these antibodies and the epitope-tagged proteins to study whether ARF6 and ARF8 interact with other proteins in vivo. These studies will provide a multifaceted view of the functions of ARF6 and ARF8, setting the stage for similar analyses of other