The Aux/IAA proteins are auxin-sensitive repressors that mediate diverse 
physiological and developmental processes in plants [1, 2]. There are 29 Aux/IAA 
genes in Arabidopsis that exhibit unique but partially overlapping patterns of 
expression [3]. Although some studies have suggested that individual Aux/IAA 
genes have specialized function, genetic analyses of the family have been 
limited by the scarcity of loss-of-function phenotypes [4]. Furthermore, with a 
few exceptions, our knowledge of the factors that regulate Aux/IAA expression is 
limited [1, 5]. We hypothesize that transcriptional control of Aux/IAA genes 
plays a central role in the establishment of the auxin-signaling pathways that 
regulate organogenesis, growth, and environmental response. Here, we describe a 
screen for transcription factors (TFs) that regulate the Aux/IAA genes. We 
identify TFs from 38 families, including 26 members of the DREB/CBF family. 
Several DREB/CBF TFs directly promote transcription of the IAA5 and IAA19 genes 
in response to abiotic stress. Recessive mutations in these IAA genes result in 
decreased tolerance to stress conditions, demonstrating a role for auxin in 
abiotic stress. Our results demonstrate that stress pathways interact with the 
auxin gene regulatory network (GRN) through transcription of the Aux/IAA genes. 
We propose that the Aux/IAA genes function as hubs that integrate genetic and 
environmental information to achieve the appropriate developmental or 
physiological outcome.