Recent studies have shed light on BR regulation of reproductive development and root growth. The transition from vegetative to reproductive growth is regulated by numerous interacting endogenous and environmental cues, such as GA, BR, photoperiod and temperature Li et al. However, whether this interaction mediates BR repression of FLC expression and promotion of flowering remains unanswered Clouse, , as REF6 activates gene expression by removing repressive H3K27me3 histone marks Lu et al.
BR may also indirectly affect flowering time by influencing the circadian clock and the photoperiod flowering pathway, as BR application shortens circadian rhythms Hanano et al.
Defects in BR biosynthesis or signalling pathways also reduce male fertility due to shortening of the stamen and defects in pollen development Ye et al.
These developmental defects correlate with the reduced expression of several key genes involved in anther and pollen development, many of which are transcriptional targets of BZR2 Ye et al. Finally, recent studies have shown that, in maize, BR controls sex determination by promoting stamen and repressing pistil development in tassels Hartwig et al. BR also promotes quiescent centre division and columella stem cell differentiation Gonzalez-Garcia et al.
Interestingly, expressing BRI1 using an epidermal-specific promoter rescued the root growth of the bri1 mutant, demonstrating that BR perception in the epidermis is sufficient to control root growth and meristem size, possibly through a mobile factor other than BZR1 or BZR2 Hacham et al. BR also plays an important role in directing epidermal cell fate in roots, where epidermal cells differentiate into hair or non-hair cells depending on their position.
Thus, regulating the expression levels of cell type-specific components seems to be a general mechanism by which BR exerts specific effects on diverse developmental responses. Over the past decade, our understanding of the BR signalling pathway has progressed rapidly thanks to a combination of genetic, proteomic and genomic approaches. The BR pathway represents the first, and still the only, fully elucidated receptor kinase signalling pathway in plants.
Its extensive molecular connections with other signalling pathways demonstrate a high degree of integration in the regulatory networks in plants.
In particular, the essential roles played by BR in plant responses to light and GA support the notion that BR is a master regulator at the centre of the plant growth regulation network. A framework has thus been established for building a detailed molecular map of the growth regulation network in plants.
Many key questions remain to be answered, however. For example, what controls the wide range of BR levels found in different tissues and organs? How do plants use BR in the context of normal development and under environmental stresses? Does BR serve as a positional cue for cell differentiation and morphogenesis? How does BR induce distinct responses in different tissues and cell types?
How is the BR pathway integrated with additional signalling pathways? Finally, how does BR signalling integrate with both by regulating and being regulated by cellular processes such as vesicle trafficking, cytoskeleton organisation, and cell wall expansion and integrity?
Answers to these questions will advance our understanding of plant growth regulation, which is important for food and bioenergy production and for environmental conservation Vriet et al. We apologise to authors whose primary work we could not cite because of space constraints. Deposited in PMC for release after 12 months. Competing interests statement. Development at a Glance. National Center for Biotechnology Information , U.
Find articles by Jia-Ying Zhu. Find articles by Juthamas Sae-Seaw. Find articles by Zhi-Yong Wang. Author information Copyright and License information Disclaimer. Published by The Company of Biologists Ltd. This article has been cited by other articles in PMC. Abstract The brassinosteroid BR class of steroid hormones regulates plant development and physiology. Keywords: Brassinosteroid, Gibberellin, Photomorphogenesis, Receptor kinase. Introduction Steroid hormones regulate gene expression and development in both plants and animals.
Open in a separate window. BR-mediated regulation of photomorphogenesis through crosstalk with other pathways Nearly all BR-regulated processes are also regulated by other hormonal or environmental signals Depuydt and Hardtke, Regulation of the light response Light switches seedling development from etiolation skotomorphogenesis to de-etiolation photomorphogenesis by inhibiting cell elongation and promoting chloroplast development and leaf expansion.
The relationship between BR and GA BR and GA are both growth-promoting hormones, having similar effects on various developmental processes throughout the life cycle of plants Depuydt and Hardtke, Crosstalk between BRI1 and other receptor kinase pathways There are over receptor kinases in Arabidopsis Shiu et al.
Crosstalk between the BRI1 and ERECTA pathways regulates stomata development Photosynthesis requires both chloroplasts and stomata, which are the epidermal valves that allow gas exchange between plant leaves and the atmosphere. BR-mediated regulation of other aspects of plant development In addition to direct crosstalk with other signalling pathways, BR also impinges on developmental pathways, often through BZR1-mediated regulation of specific developmental regulators.
Regulation of reproductive development The transition from vegetative to reproductive growth is regulated by numerous interacting endogenous and environmental cues, such as GA, BR, photoperiod and temperature Li et al.
Perspectives Over the past decade, our understanding of the BR signalling pathway has progressed rapidly thanks to a combination of genetic, proteomic and genomic approaches. Acknowledgments We apologise to authors whose primary work we could not cite because of space constraints. Competing interests statement The authors declare no competing financial interests. References Albrecht C. Brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent of the receptor kinase BAK1.
Functions of OsBZR1 and proteins in brassinosteroid signaling in rice. Brassinosteroid, gibberellin and phytochrome impinge on a common transcription module in Arabidopsis.
Cell Biol. Brassinosteroids modulate the efficiency of plant immune responses to microbe-associated molecular patterns. One for all: the receptor-associated kinase BAK1. Trends Plant Sci. Phenotypic and genetic analysis of det2, a new mutant that affects light-regulated seedling development in Arabidopsis. Plant J. Brassinosteroid signal transduction: from receptor kinase activation to transcriptional networks regulating plant development.
A brassinosteroid-insensitive mutant in Arabidopsis thaliana exhibits multiple defects in growth and development. Plant Physiol. A molecular framework for light and gibberellin control of cell elongation. Hormone signalling crosstalk in plant growth regulation. Attenuation of brassinosteroid signaling enhances FLC expression and delays flowering. Stomatal patterning and development. BZS1, a B-box protein, promotes photomorphogenesis downstream of both brassinosteroid and light signaling pathways.
Coordinated regulation of Arabidopsis thaliana development by light and gibberellins. Molecular mechanism for the interaction between gibberellin and brassinosteroid signaling pathways in Arabidopsis. An essential role for proteins in brassinosteroid signal transduction in Arabidopsis. Endosomal signaling of plant steroid receptor kinase BRI1. Genes Dev. Brassinosteroids control meristem size by promoting cell cycle progression in Arabidopsis roots. Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid signaling.
PLoS Genet. Plants grow on brassinosteroids. Plant Biol. Brassinosteroid perception in the epidermis controls root meristem size. Multiple phytohormones influence distinct parameters of the plant circadian clock. Brassinosteroid control of sex determination in maize. BZR1 is a transcriptional repressor with dual roles in brassinosteroid homeostasis and growth responses. EMBO J. Structural basis of steroid hormone perception by the receptor kinase BRI1.
Plant Mol. Brassinosteroid signaling and auxin transport are required to establish the periodic pattern of Arabidopsis shoot vascular bundles. Fluorescent castasterone reveals BRI1 signaling from the plasma membrane. Tyrosine phosphorylation controls brassinosteroid receptor activation by triggering membrane release of its kinase inhibitor.
Brassinosteroid signal transduction from receptor kinases to transcription factors. Brassinosteroid signal transduction from cell-surface receptor kinases to nuclear transcription factors.
Binding of brassinosteroids to the extracellular domain of plant receptor kinase BRI1. The chloroplast protein BPG2 functions in brassinosteroid-mediated post-transcriptional accumulation of chloroplast rRNA. Steroids are required for epidermal cell fate establishment in Arabidopsis roots. Role of actin cytoskeleton in brassinosteroid signaling and in its integration with the auxin response in plants.
Meyerowitz E. Tyrosine phosphorylation controls brassinosteroid receptor activation by triggering membrane release of its kinase inhibitor.
Genes Dev. Janssens V. Longin S. Goris J. PP2A holoenzyme assembly: in cauda venenum the sting is in the tail. Trends Biochem. Karlova R. Boeren S. Aker J. Vervoort J. Plant Cell 18 : — Kauschmann A. Jessop A. Koncz C. Szekeres M. Willmitzer L. Genetic evidence for an essential role of brassinosteroids in plant development.
Kim T. Guan S. Deng Z. Tang W. Shang J. Burlingame A. Brassinosteroid signal transduction from cell-surface receptor kinases to nuclear transcription factors. Brassinosteroid signal transduction from receptor kinases to transcription factors.
Kinoshita T. Seto H. Hiranuma S. Binding of brassinosteroids to the extracellular domain of plant receptor kinase BRI1. Nature : — Koka C. Cerny R. Gardner R. Noguchi T. Lee S. Yang K. Kim Y. Park S. Kim S. Soh M. Overexpression of PRE1 and its homologous genes activates Gibberellin-dependent responses in Arabidopsis thaliana.
Plant Cell Physiol. Lemmon M. Schlessinger J. Cell signaling by receptor tyrosine kinases. Multi-tasking of somatic embryogenesis receptor-like protein kinases. Regulation of the nuclear activities of brassinosteroid signaling. A putative leucine-rich repeat receptor kinase involved in brassinosteroid signal transduction. Cell 90 : — Chen S. Involvement of brassinosteroid signals in the floral-induction network of Arabidopsis. Nam K. Wen J. Lease K. Doke J. Tax F. Walker J. Guo H. Yin Y. Arabidopsis IWS1 interacts with transcription factor BES1 and is involved in plant steroid hormone brassinosteroid regulated gene expression.
Thompson A. Guo M. Lim W. Pawson T. Phosphotyrosine signaling: Evolving a new cellular communication system. Luo X. Integration of light- and brassinosteroid-signaling pathways by a GATA transcription factor in Arabidopsis. Cell 19 : — Mandava N. Plant growth-promoting brassinosteroids. Mara C. Huang T. Irish V. Mayumi K. Shibaoka H. A possible double role for brassinolide in the re-orientation of cortical microtubules in the epidermal cells of Azuki bean epicotyls.
Nomura T. Farrar K. Kaneta T. Plant Cell 14 : — Vert G. Cheong H. Nuclear protein phosphatases with Kelch-repeat domains modulate the response to brassinosteroids in Arabidopsis. Choe S. Yuan H.
Brassinosteroid-insensitive dwarf mutants of Arabidopsis accumulate brassinosteroids. Nole-Wilson S. Rueschhoff E. Bhatti H. Franks R. Synergistic disruptions in seuss cyp85A2 double mutants reveal a role for brassinolide synthesis during gynoecium and ovule development. BMC Plant Biol. Reid J. Wang X. Kota U. Tyrosine phosphorylation of the BRI1 receptor kinase emerges as a component of brassinosteroid signaling in Arabidopsis.
Zhao Y. Autophosphorylation of Tyr in the receptor kinase BAK1 plays a role in brassinosteroid signaling and basal defense gene expression. Specificity in signal transduction: From phosphotyrosine-SH2 domain interactions to complex cellular systems. Peng P. Zhao J. Zhu Y. A direct docking mechanism for a plant GSK3-like kinase to phosphorylate its substrates.
Postel S. Beuter C. Mazzotta S. Schwedt A. Borlotti A. Halter T. The multifunctional leucine-rich repeat receptor kinase BAK1 is implicated in Arabidopsis development and immunity. Rozhon W. Mayerhofer J. Petutschnig E. Jonak C. Borst J. Kwaaitaal M. Plant Cell 16 : — Ryu H. Cho H. Kim K. Hwang I. Phosphorylation dependent nucleocytoplasmic shuttling of BES1 is a key regulatory event in brassinosteroid signaling.
Cells 29 : — Park J. Nucleocytoplasmic shuttling of BZR1 mediated by phosphorylation is essential in Arabidopsis brassinosteroid signaling. Schlereth A. Liu W. Kientz M. Flipse J. Rademacher E. Schmid M. Weijers D. Schulze B. Mentzel T. Jehle A. Mueller K. Beeler S. Boller T. Felix G.
Rapid heteromerization and phosphorylation of ligand-activated plant transmembrane receptors and their associated kinase BAK1. Shiu S. Karlowski W. Pan R. Tzeng Y. Mayer K. Comparative analysis of the receptor-like kinase family in Arabidopsis and rice. Integration of brassinosteroid signal transduction with the transcription network for plant growth regulation in Arabidopsis. Fokar M. Allen R. Characterization of the brassinosteroid insensitive 1 genes of cotton.
Symons G. Hormone levels and response during de-etiolation in pea. Planta : — Smith J. Davies N. The hormonal regulation of de-etiolation. Tanaka A. Oses-Prieto J. Suzuki N. Zhang X. Proteomics studies of brassinosteroid signal transduction using prefractionation and two-dimensional DIGE. Proteomics 7 : — Wang R.
PP2A activates brassinosteroid-responsive gene expression and plant growth by dephosphorylating BZR1. Toledo-Ortiz G. Huq E. Quail P. Plant Cell 15 : — Downstream nuclear events in brassinosteroid signalling. Nature : 96 — Nemhauser J. Geldner N.
Hong F. Molecular mechanisms of steroid hormone signaling in plants. Cell Dev. Wada K. Marumo S. Abe H. Morishita T. Nakamura K. Uchiyama M. Mori K. A rice lamina inclination test-amicro-quantitative bioassay for brassinosteroids. Wang H. Regulation of Arabidopsis brassinosteroid signaling by atypical basic helix-loop-helix proteins. Plant Cell 21 : — Soderblom E. Phinney B. Kuchar J. Plant Cell 17 : — Blackburn K. Cell 15 : — Meisenhelder J. Autoregulation and homodimerization are involved in the activation of the plant steroid receptor BRI1.
Cell 8 : — Zhu L. Liu B. Wang C. Jin L. Zhao Q. Yuan M. Nakano T. Chen M. Vafeados D. Yang Y. Nuclear-localized BZR1 mediates brassinosteroid-induced growth and feedback suppression of brassinosteroid biosynthesis. Cell 2 : — Waters M. Wang P. Korkaric M. Capper R. Saunders N. Langdale J. GLK transcription factors coordinate expression of the photosynthetic apparatus in Arabidopsis. Yamamuro C. Ihara Y.
Ashikari M. Kitano H. Matsuoka M. Loss of function of a rice brassinosteroid insensitive1 homolog prevents internode elongation and bending of the lamina joint. Plant Cell 12 : — Yan Z. Chihara R. Zhu W. Zhang S. Brassinosteroids control male fertility by regulating the expression of key genes involved in Arabidopsis anther and pollen development.
Tao Y. A new class of transcription factors mediates brassinosteroid-regulated gene expression in Arabidopsis. Mora-Garcia S. BES1 accumulates in the nucleus in response to brassinosteroids to regulate gene expression and promote stem elongation.
Zola J. Aluru M. Foudree A. Anderson S. Aluru S. Liu P. Rodermel S. A brassinosteroid transcriptional network revealed by genome-wide identification of BESI target genes in Arabidopsis thaliana. Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Sign In.
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Abstract Brassinosteroid BR signal transduction research has progressed rapidly from the initial discovery of the BR receptor to a complete definition of the basic molecular components required to relay the BR signal from perception by receptor kinases at the cell surface to activation of a small family of transcription factors that regulate the expression of more than a thousand genes in a BR-dependent manner.
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