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.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Cellular Signaling and Regulatory Systems Study Section (CSRS)
Program Officer
Maas, Stefan
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Carnegie Institution of Washington, D.C.
United States
Zip Code
Zhu, Jia-Ying; Li, Yuyao; Cao, Dong-Mei et al. (2017) The F-box Protein KIB1 Mediates Brassinosteroid-Induced Inactivation and Degradation of GSK3-like Kinases in Arabidopsis. Mol Cell 66:648-657.e4
Deng, Zhiping; Wang, Zhi-Yong; Kutschera, Ulrich (2017) Seedling development in maize cv. B73 and blue light-mediated proteomic changes in the tip vs. stem of the coleoptile. Protoplasma 254:1317-1322
Bu, Shuo-Lei; Liu, Chao; Liu, Ning et al. (2017) Immunopurification and Mass Spectrometry Identifies Protein Phosphatase 2A (PP2A) and BIN2/GSK3 as Regulators of AKS Transcription Factors in Arabidopsis. Mol Plant 10:345-348
Ni, Weimin; Xu, Shou-Ling; González-Grandío, Eduardo et al. (2017) PPKs mediate direct signal transfer from phytochrome photoreceptors to transcription factor PIF3. Nat Commun 8:15236
Xu, Shou-Ling; Chalkley, Robert J; Maynard, Jason C et al. (2017) Proteomic analysis reveals O-GlcNAc modification on proteins with key regulatory functions in Arabidopsis. Proc Natl Acad Sci U S A 114:E1536-E1543
Chaiwanon, Juthamas; Garcia, Veder J; Cartwright, Heather et al. (2016) Immunophilin-like FKBP42/TWISTED DWARF1 Interacts with the Receptor Kinase BRI1 to Regulate Brassinosteroid Signaling in Arabidopsis. Mol Plant 9:593-600
Kutschera, Ulrich; Wang, Zhi-Yong (2016) Growth-limiting proteins in maize coleoptiles and the auxin-brassinosteroid hypothesis of mesocotyl elongation. Protoplasma 253:3-14
Zhang, Zhenzhen; Zhu, Jia-Ying; Roh, Jeehee et al. (2016) TOR Signaling Promotes Accumulation of BZR1 to Balance Growth with Carbon Availability in Arabidopsis. Curr Biol 26:1854-60
Chaiwanon, Juthamas; Wang, Wenfei; Zhu, Jia-Ying et al. (2016) Information Integration and Communication in Plant Growth Regulation. Cell 164:1257-1268
Wei, Chuang-Qi; Chien, Chih-Wei; Ai, Lian-Feng et al. (2016) The Arabidopsis B-box protein BZS1/BBX20 interacts with HY5 and mediates strigolactone regulation of photomorphogenesis. J Genet Genomics 43:555-563

Showing the most recent 10 out of 59 publications