The long-term goal of this project is to understand the molecular network through which brassinosteroid (BR) and other hormonal and environmental signals together control plant growth and development. Steroids are important hormones in both plants and animals. BR regulates a wide range of developmental and physiological processes in plants through a signal transduction pathway from cell- surface receptor kinases (BRI1) to nuclear transcription factors (BZR1 and BZR2/BES1). BR acts together with other hormonal and environmental signals to regulate plant development and physiology, and has particularly intimate relationships with light and gibberellin (GA). We have made great progress in understanding the molecular details of how BR binding to BRI1 leads to activation of BZR1 and regulation of over a thousand target genes. Furthermore, we have gained insights into how the BR signaling pathway is wired together with other pathways to control various functions in plants. For this renewal proposal, we plan to understand how the BR signaling pathway crosstalks with the stomata receptor kinase pathway and the light and gibberellin signaling pathways to coordinate cell differentiation and plant development. We will use a combination of genetic, proteomic, and genomic approaches to achieve the following specific Aims. 1) We will study how BR signaling regulates the MAP kinases and crosstalks with the ERECTA family receptor kinases to regulate stomata differentiation. 2) We will elucidate the mechanism of integration of the BR and light signaling pathways, by characterizing the interaction between BZR1 and the phytochrome- interacting factors (PIFs) in regulating common target genes, and the functions of three BZR1-target transcription factors in light regulation of gene expression and development. 3) We will study the molecular mechanisms by which BR and GA hormones orchestrate common developmental processes. The experiments proposed in this proposal will elucidate a regulatory network that integrates four important signaling pathways controlling plant growth. This will greatly advance our understanding of not only the molecular mechanisms of signal transduction but also the mechanisms of signaling pathway integration. Although the BR signaling pathway is distinct from the nuclear receptor-mediated steroid signaling mechanism in animals, many components and signaling mechanisms used by the BR pathway are conserved and play important roles in either steroid regulated processes or other signaling pathways in animals. Thus, this study not only is important for plant biology and agriculture, but also can potentially help us understand fundamental mechanisms of steroid function and cellular regulation that are relevant to human health.

Public Health Relevance

Steroids are important growth hormones in both animals and plants. The brassinosteroid hormone is major growth promoting hormone that control a wide range of activities in plants. Brassinosteroid signal transduction uses many proteins that are similar to important proteins in humans, and understanding the functional mechanisms of these proteins will lead to not only means for improving crop yield but also knowledge that benefit human health.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM066258-10A1
Application #
8294084
Study Section
Cellular Signaling and Regulatory Systems Study Section (CSRS)
Program Officer
Maas, Stefan
Project Start
2002-08-01
Project End
2016-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
10
Fiscal Year
2012
Total Cost
$349,772
Indirect Cost
$107,236
Name
Carnegie Institution of Washington, D.C.
Department
Type
DUNS #
072641707
City
Washington
State
DC
Country
United States
Zip Code
20005
Fan, Min; Bai, Ming-Yi; Kim, Jung-Gun et al. (2014) The bHLH transcription factor HBI1 mediates the trade-off between growth and pathogen-associated molecular pattern-triggered immunity in Arabidopsis. Plant Cell 26:828-41
Oh, Eunkyoo; Zhu, Jia-Ying; Ryu, Hojin et al. (2014) TOPLESS mediates brassinosteroid-induced transcriptional repression through interaction with BZR1. Nat Commun 5:4140
Arenhart, Rafael Augusto; Bai, Yang; de Oliveira, Luiz Felipe Valter et al. (2014) New insights into aluminum tolerance in rice: the ASR5 protein binds the STAR1 promoter and other aluminum-responsive genes. Mol Plant 7:709-21
Oh, Eunkyoo; Zhu, Jia-Ying; Bai, Ming-Yi et al. (2014) Cell elongation is regulated through a central circuit of interacting transcription factors in the Arabidopsis hypocotyl. Elife 3:
Ni, Weimin; Xu, Shou-Ling; Tepperman, James M et al. (2014) A mutually assured destruction mechanism attenuates light signaling in Arabidopsis. Science 344:1160-4
Xu, Peng; Xu, Shou-Ling; Li, Zi-Jing et al. (2014) A brassinosteroid-signaling kinase interacts with multiple receptor-like kinases in Arabidopsis. Mol Plant 7:441-4
Wang, Wenfei; Wang, Zhi-Yong (2014) At the intersection of plant growth and immunity. Cell Host Microbe 15:400-2
Deng, Zhiping; Oses-Prieto, Juan A; Kutschera, Ulrich et al. (2014) Blue light-induced proteomic changes in etiolated Arabidopsis seedlings. J Proteome Res 13:2524-33
Zhu, Jia-Ying; Sae-Seaw, Juthamas; Wang, Zhi-Yong (2013) Brassinosteroid signalling. Development 140:1615-20
Fan, Xi-Ying; Sun, Yu; Cao, Dong-Mei et al. (2012) BZS1, a B-box protein, promotes photomorphogenesis downstream of both brassinosteroid and light signaling pathways. Mol Plant 5:591-600

Showing the most recent 10 out of 30 publications