Postdoctoral associate Duke University Durham, North Carolina
Body of Abstract: Auxin regulates nearly all aspects of plant growth and development. Importantly, auxin also integratesenvironmental signals into growth outputs, includingresponses to drought and temperature. However, auxin’s role in most abiotic stresses remains elusive. Auxin-regulated transcriptional outputs are mediated by a family of AUXIN RESPONSE FACTORs (ARFs). ARF7 is a positive regulator of auxin response with known roles in auxin-mediated growth responses and is active in both the root and shoot tissues. Recently, the Strader lab found that ARF7 protein accumulation increases under heat stress. We assessed the endogenous levels of ARF7 in whole seedlings of 60 naturally occurring Arabidopsis accessions at ambient and heat stress temperatures using an ARF7 antibody. From this screen, we identified natural accessions that displayed altered accumulation of ARF7 under heat stress and those that did not. Further, using this data, we performed a Genome wide analysis to identify candidate genes responsible for ARF7 protein accumulation under heat stress. Using mutants, we have narrowed down our candidate genes and have found several mutants that fail to increase endogenous ARF7protein accumulation under heat stress. These mutants provide mechanistic insight into ARF7 accumulation and the integration of environmental cues into auxin signal transduction.