Plants' ability to respond to light is crucial for their survival. Recent evidence implicating brassinosteroids (BRs) in the light response has made the identification of brassinosteroid response components of great interest. Seedlings unable to synthesize BRs develop as light-grown plants even when grown in darkness. Moreover, these mutants reveal a significant role for BRs throughout development. Traditional screens attempting to identify components of the BR response and signaling pathway have been hampered by failure to uncover mutations in all but one gene, BRI1. Several explanations for why only one gene was identified in these screens are possible. Two of the most likely are that the genes required for BR response are involved in other pathways (thus yielding phenotypes distinct from BR synthetic mutants) and/or that these genes are redundant or essential for viability. I will use novel approaches to circumvent these obstacles and identify new components of BR signaling. In the first of these approaches, quantitative trait loci analysis on disparate Arabidopsis ecotypes will allow me to first localize and then clone new BR response elements. Secondly, characterization of BR: auxin synergy in Arabidopsis will define a new niche of BR research. This striking example of communication between hormone pathways presents an opportunity to better understand the signaling of each hormone alone as well as the nodes of intersection between them.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM020742-02
Application #
6489927
Study Section
Biological Sciences 2 (BIOL)
Program Officer
Wolfe, Paul B
Project Start
2000-12-04
Project End
Budget Start
2001-12-04
Budget End
2002-12-03
Support Year
2
Fiscal Year
2002
Total Cost
$38,320
Indirect Cost
Name
Salk Institute for Biological Studies
Department
Type
DUNS #
005436803
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Nemhauser, Jennifer L; Mockler, Todd C; Chory, Joanne (2004) Interdependency of brassinosteroid and auxin signaling in Arabidopsis. PLoS Biol 2:E258
Nemhauser, Jennifer L; Maloof, Julin N; Chory, Joanne (2003) Building integrated models of plant growth and development. Plant Physiol 132:436-9
Friedrichsen, Danielle M; Nemhauser, Jennifer; Muramitsu, Takamichi et al. (2002) Three redundant brassinosteroid early response genes encode putative bHLH transcription factors required for normal growth. Genetics 162:1445-56