heterocyclic steroids


Summary: Steroidal compounds in which one or more carbon atoms in the steroid ring system have been substituted with non-carbon atoms.

Top Publications

  1. Duan K, Li L, Hu P, Xu S, Xu Z, Xue H. A brassinolide-suppressed rice MADS-box transcription factor, OsMDP1, has a negative regulatory role in BR signaling. Plant J. 2006;47:519-31 pubmed
  2. Tang W, Kim T, Oses Prieto J, Sun Y, Deng Z, Zhu S, et al. BSKs mediate signal transduction from the receptor kinase BRI1 in Arabidopsis. Science. 2008;321:557-60 pubmed publisher
    ..These results demonstrate that BSKs are the substrates of BRI1 kinase that activate downstream BR signal transduction. ..
  3. Tanaka K, Asami T, Yoshida S, Nakamura Y, Matsuo T, Okamoto S. Brassinosteroid homeostasis in Arabidopsis is ensured by feedback expressions of multiple genes involved in its metabolism. Plant Physiol. 2005;138:1117-25 pubmed
    ..Moreover, a weak response in the mutant suggests that DWF4 alone is likely to be regulated in other way(s) in addition to BRI1 mediation. ..
  4. He J, Fujioka S, Li T, Kang S, Seto H, Takatsuto S, et al. Sterols regulate development and gene expression in Arabidopsis. Plant Physiol. 2003;131:1258-69 pubmed
  5. Yun H, Bae Y, Lee Y, Chang S, Kim S, Li J, et al. Analysis of phosphorylation of the BRI1/BAK1 complex in arabidopsis reveals amino acid residues critical for receptor formation and activation of BR signaling. Mol Cells. 2009;27:183-90 pubmed publisher
    ..These results suggest that BAK1 is a critical component regulating the duration of BR efficacy, even though it cannot directly bind BRs in plants. ..
  6. Poppenberger B, Fujioka S, Soeno K, George G, Vaistij F, Hiranuma S, et al. The UGT73C5 of Arabidopsis thaliana glucosylates brassinosteroids. Proc Natl Acad Sci U S A. 2005;102:15253-8 pubmed
    ..These data support the hypothesis that 23-O-glucosylation of BL is a function of UGT73C5 in planta, and that glucosylation regulates BR activity. ..
  7. Kinoshita T, Caño Delgado A, Seto H, Hiranuma S, Fujioka S, Yoshida S, et al. Binding of brassinosteroids to the extracellular domain of plant receptor kinase BRI1. Nature. 2005;433:167-71 pubmed
    ..Our results demonstrate that brassinosteroids bind directly to the 94 amino acids comprising ID-LRR22 in the extracellular domain of BRI1, and define a new binding domain for steroid hormones. ..
  8. Clouse S, Langford M, McMorris T. A brassinosteroid-insensitive mutant in Arabidopsis thaliana exhibits multiple defects in growth and development. Plant Physiol. 1996;111:671-8 pubmed
    ..The multiple and dramatic effects of mutation of the BRI1 locus on development suggests that the BRI1 gene may play a critical role in brassinosteroid perception or signal transduction. ..
  9. Hardtke C, Dorcey E, Osmont K, Sibout R. Phytohormone collaboration: zooming in on auxin-brassinosteroid interactions. Trends Cell Biol. 2007;17:485-92 pubmed
    ..Moreover, auxin and brassinosteroid signaling and biosynthesis and auxin transport might be linked by an emerging upstream connection involving calcium-calmodulin and phosphoinositide signaling. ..

More Information


  1. Zurek D, Clouse S. Molecular cloning and characterization of a brassinosteroid-regulated gene from elongating soybean (Glycine max L.) epicotyls. Plant Physiol. 1994;104:161-70 pubmed
    ..The elevated levels of BRU1 transcripts in elongating tissue and the homology with a xyloglucan endotransglycosylase suggest a possible role for the BRU1 protein in brassinosteroid-stimulated elongation. ..
  2. Wang X, Li X, Meisenhelder J, Hunter T, Yoshida S, Asami T, et al. Autoregulation and homodimerization are involved in the activation of the plant steroid receptor BRI1. Dev Cell. 2005;8:855-65 pubmed
    ..Our results support a BRI1-activation model that involves inhibition of kinase activity by its C-terminal domain, which is relieved upon ligand binding to the extracellular domain. ..
  3. Bao F, Shen J, Brady S, Muday G, Asami T, Yang Z. Brassinosteroids interact with auxin to promote lateral root development in Arabidopsis. Plant Physiol. 2004;134:1624-31 pubmed
  4. de Vries S. 14-3-3 proteins in plant brassinosteroid signaling. Dev Cell. 2007;13:162-4 pubmed
    ..In this issue of Developmental Cell, Gampala et al. show that this redistribution may fine-tune BR responses and serve to crosstalk with other signaling pathways. ..
  5. Goda H, Sawa S, Asami T, Fujioka S, Shimada Y, Yoshida S. Comprehensive comparison of auxin-regulated and brassinosteroid-regulated genes in Arabidopsis. Plant Physiol. 2004;134:1555-73 pubmed
  6. Hong Z, Ueguchi Tanaka M, Shimizu Sato S, Inukai Y, Fujioka S, Shimada Y, et al. Loss-of-function of a rice brassinosteroid biosynthetic enzyme, C-6 oxidase, prevents the organized arrangement and polar elongation of cells in the leaves and stem. Plant J. 2002;32:495-508 pubmed
    ..On the basis of these findings, we discuss the biological function of BRs in rice plants. ..
  7. Wang L, Wang Z, Xu Y, Joo S, Kim S, Xue Z, et al. OsGSR1 is involved in crosstalk between gibberellins and brassinosteroids in rice. Plant J. 2009;57:498-510 pubmed publisher
    ..These results demonstrate that OsGSR1 plays important roles in both BR and GA pathways, and also mediates an interaction between the two signaling pathways. ..
  8. Goda H, Shimada Y, Asami T, Fujioka S, Yoshida S. Microarray analysis of brassinosteroid-regulated genes in Arabidopsis. Plant Physiol. 2002;130:1319-34 pubmed
    ..The list of BR-regulated genes will be useful in the characterization of new mutants and new growth-regulating compounds that are associated with BR function. ..
  9. Yu J, Huang L, Hu W, Zhou Y, Mao W, Ye S, et al. A role for brassinosteroids in the regulation of photosynthesis in Cucumis sativus. J Exp Bot. 2004;55:1135-43 pubmed
    ..It was concluded that EBR increases the capacity of CO(2) assimilation in the Calvin cycle, which was mainly attributed to an increase in the initial activity of Rubisco. ..
  10. Pullman G, Zhang Y, Phan B. Brassinolide improves embryogenic tissue initiation in conifers and rice. Plant Cell Rep. 2003;22:96-104 pubmed
    ..61 mg/l kinetin, 3.4 mg/l silver nitrate, 10 micro M cGMP, 0.1 micro M brassinolide, and 2 g/l Gelrite. Across 12 open-pollinated families of loblolly pine, initiation percentages ranged from 2.5% to 50.7%, averaging 22.5%...
  11. Fujioka S, Takatsuto S, Yoshida S. An early C-22 oxidation branch in the brassinosteroid biosynthetic pathway. Plant Physiol. 2002;130:930-9 pubmed
  12. Caño Delgado A, Yin Y, Yu C, Vafeados D, Mora Garcia S, Cheng J, et al. BRL1 and BRL3 are novel brassinosteroid receptors that function in vascular differentiation in Arabidopsis. Development. 2004;131:5341-51 pubmed
    ..bri1 brl1 brl3 triple mutants enhance bri1 dwarfism and also exhibit abnormal vascular differentiation. Thus, Arabidopsis contains a small number of BR receptors that have specific functions in cell growth and vascular differentiation. ..
  13. Wang X, Kota U, He K, Blackburn K, Li J, Goshe M, et al. Sequential transphosphorylation of the BRI1/BAK1 receptor kinase complex impacts early events in brassinosteroid signaling. Dev Cell. 2008;15:220-35 pubmed publisher
    ..This model suggests both conservation and distinct differences between the molecular mechanisms regulating phosphorylation-dependent kinase activation in plant and animal receptor kinases. ..
  14. Wang Z, Wang Q, Chong K, Wang F, Wang L, Bai M, et al. The brassinosteroid signal transduction pathway. Cell Res. 2006;16:427-34 pubmed
    ..The BR signaling pathway has become a paradigm for both receptor kinase signaling in plants and steroid signaling by cell surface receptors in general. ..
  15. Dhaubhadel S, Browning K, Gallie D, Krishna P. Brassinosteroid functions to protect the translational machinery and heat-shock protein synthesis following thermal stress. Plant J. 2002;29:681-91 pubmed
  16. Vidya Vardhini B, Rao S. Acceleration of ripening of tomato pericarp discs by brassinosteroids. Phytochemistry. 2002;61:843-7 pubmed
    ..Fruit ripening as induced by brassinosteroids was associated with increase in ethylene production. The study revealed the ability of brassinosteroids in accelerating fruit-senescence. ..
  17. Szekeres M, Nemeth K, Koncz Kalman Z, Mathur J, Kauschmann A, Altmann T, et al. Brassinosteroids rescue the deficiency of CYP90, a cytochrome P450, controlling cell elongation and de-etiolation in Arabidopsis. Cell. 1996;85:171-82 pubmed
    ..Brassinosteroids also compensate for different cell elongation defects of Arabidopsis det, cop, fus, and axr2 mutants, indicating that these steroids play an essential role in the regulation of plant development. ..
  18. Hu Y, Bao F, Li J. Promotive effect of brassinosteroids on cell division involves a distinct CycD3-induction pathway in Arabidopsis. Plant J. 2000;24:693-701 pubmed
    ..Induction was also found to occur in cells of a BR-insensitive mutant, bri1, suggesting that BR induces CycD3 transcription through a previously unknown signal pathway in plants. ..
  19. Friedrichsen D, Nemhauser J, Muramitsu T, Maloof J, Alonso J, Ecker J, et al. Three redundant brassinosteroid early response genes encode putative bHLH transcription factors required for normal growth. Genetics. 2002;162:1445-56 pubmed
    ..Reduced ABA response in plants overexpressing BEE1 suggests that BEE proteins may function as signaling intermediates in multiple pathways. ..
  20. Kagale S, Divi U, Krochko J, Keller W, Krishna P. Brassinosteroid confers tolerance in Arabidopsis thaliana and Brassica napus to a range of abiotic stresses. Planta. 2007;225:353-64 pubmed
    ..Both det2-1 and dwf4 mutants still expressed heat shock proteins (hsps) to high levels during HS, indicating that although BR augments thermotolerance in plants, it is not necessary for hsp expression during HS. ..
  21. Hardtke C. Transcriptional auxin-brassinosteroid crosstalk: who's talking?. Bioessays. 2007;29:1115-23 pubmed
    ..This article reviews the evidence for transcriptional crosstalk between auxin and brassinosteroid and its molecular basis. ..
  22. Nakamura A, Higuchi K, Goda H, Fujiwara M, Sawa S, Koshiba T, et al. Brassinolide induces IAA5, IAA19, and DR5, a synthetic auxin response element in Arabidopsis, implying a cross talk point of brassinosteroid and auxin signaling. Plant Physiol. 2003;133:1843-53 pubmed
  23. Bishop G, Koncz C. Brassinosteroids and plant steroid hormone signaling. Plant Cell. 2002;14 Suppl:S97-110 pubmed
  24. Hong Z, Ueguchi Tanaka M, Umemura K, Uozu S, Fujioka S, Takatsuto S, et al. A rice brassinosteroid-deficient mutant, ebisu dwarf (d2), is caused by a loss of function of a new member of cytochrome P450. Plant Cell. 2003;15:2900-10 pubmed
    ..Based on these results, we conclude that D2/CYP90D2 catalyzes the steps from 6-deoxoteasterone to 3-dehydro-6-deoxoteasterone and from teasterone to 3-dehydroteasterone in the late BR biosynthesis pathway. ..
  25. Kitanaga Y, Jian C, Hasegawa M, Yazaki J, Kishimoto N, Kikuchi S, et al. Sequential regulation of gibberellin, brassinosteroid, and jasmonic acid biosynthesis occurs in rice coleoptiles to control the transcript levels of anti-microbial thionin genes. Biosci Biotechnol Biochem. 2006;70:2410-9 pubmed
    ..In contrast, thionin gene expression in etiolated seedlings remained high while the endogenous level of JA was low, suggesting the presence of another signaling pathway in the dark to maintain the thionin level. ..
  26. Choe S, Schmitz R, Fujioka S, Takatsuto S, Lee M, Yoshida S, et al. Arabidopsis brassinosteroid-insensitive dwarf12 mutants are semidominant and defective in a glycogen synthase kinase 3beta-like kinase. Plant Physiol. 2002;130:1506-15 pubmed
  27. Müssig C. Brassinosteroid-promoted growth. Plant Biol (Stuttg). 2005;7:110-7 pubmed
    ..This review focuses on physiology and molecular mechanisms underlying BR-promoted growth in the different plant organs. Interactions with other phytohormones are discussed. ..
  28. Fujioka S, Yokota T. Biosynthesis and metabolism of brassinosteroids. Annu Rev Plant Biol. 2003;54:137-64 pubmed
    ..Various metabolic reactions of BRs including epimerization, oxidation, and conjugation are also summarized. ..
  29. Wang X, Chory J. Brassinosteroids regulate dissociation of BKI1, a negative regulator of BRI1 signaling, from the plasma membrane. Science. 2006;313:1118-22 pubmed
    ..BKI1 is a substrate of BRI1 kinase and limits the interaction of BRI1 with its proposed coreceptor, BAK1, suggesting that BKI1 prevents the activation of BRI1. ..
  30. Nakaya M, Tsukaya H, Murakami N, Kato M. Brassinosteroids control the proliferation of leaf cells of Arabidopsis thaliana. Plant Cell Physiol. 2002;43:239-44 pubmed
    ..Restoration of leaf size could not be explained solely on the basis of an increase in individual cell volume, thus suggesting that brassinosteroids play a dual role in regulating cell expansion and proliferation. ..
  31. Wang Z, Seto H, Fujioka S, Yoshida S, Chory J. BRI1 is a critical component of a plasma-membrane receptor for plant steroids. Nature. 2001;410:380-3 pubmed
  32. Hu Y, Poh H, Chua N. The Arabidopsis ARGOS-LIKE gene regulates cell expansion during organ growth. Plant J. 2006;47:1-9 pubmed
    ..Ectopic expression of ARL in bri1-119 partially restores cell growth in cotyledons and leaves. Our results suggest that ARL acts downstream of BRI1 and partially mediates BR-related cell expansion signals during organ growth. ..
  33. Bajguz A. Brassinosteroid enhanced the level of abscisic acid in Chlorella vulgaris subjected to short-term heat stress. J Plant Physiol. 2009;166:882-6 pubmed publisher
    ..The present work also demonstrates that Chlorella vulgaris can synthesize ABA. This is the first evidence of ABA detection in Chlorella vulgaris cells...
  34. Sakamoto T, Morinaka Y, Ohnishi T, Sunohara H, Fujioka S, Ueguchi Tanaka M, et al. Erect leaves caused by brassinosteroid deficiency increase biomass production and grain yield in rice. Nat Biotechnol. 2006;24:105-9 pubmed
    ..These results suggest that regulated genetic modulation of brassinosteroid biosynthesis can improve crops without the negative environmental effects of fertilizers. ..
  35. Kim T, Hwang J, Kim Y, Joo S, Chang S, Lee J, et al. Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis. Plant Cell. 2005;17:2397-412 pubmed
    ..Mutant studies also revealed that BL may not always be necessary for normal growth and development but that Arabidopsis plants acquire great benefit in terms of growth and development in the presence of BL. ..
  36. Nomura T, Kushiro T, Yokota T, Kamiya Y, Bishop G, Yamaguchi S. The last reaction producing brassinolide is catalyzed by cytochrome P-450s, CYP85A3 in tomato and CYP85A2 in Arabidopsis. J Biol Chem. 2005;280:17873-9 pubmed publisher
    ..We postulate that castasterone is the major active brassinosteroid during vegetative growth in tomato, whereas brassinolide may play an organ-specific role in fruit development in this species...
  37. Bouquin T, Meier C, Foster R, Nielsen M, Mundy J. Control of specific gene expression by gibberellin and brassinosteroid. Plant Physiol. 2001;127:450-8 pubmed
    ..Reporter transgene analyses and RNA-blot analysis showed that BR and GA modulate GA5 expression, at least in part, at the transcriptional level, and that the signals are independent and subtractive. ..
  38. Li J, Chory J. A putative leucine-rich repeat receptor kinase involved in brassinosteroid signal transduction. Cell. 1997;90:929-38 pubmed
    ..The extracellular domain contains 25 tandem leucine-rich repeats that resemble repeats found in animal hormone receptors, plant disease resistance genes, and genes involved in unknown signaling pathways controlling plant development. ..
  39. De Rybel B, Audenaert D, Vert G, Rozhon W, Mayerhofer J, Peelman F, et al. Chemical inhibition of a subset of Arabidopsis thaliana GSK3-like kinases activates brassinosteroid signaling. Chem Biol. 2009;16:594-604 pubmed publisher
    ..The opportunity to generate multiple and conditional knockouts in key regulators in the BR signaling pathway by bikinin represents a useful tool to further unravel regulatory mechanisms. ..
  40. Shimada Y, Goda H, Nakamura A, Takatsuto S, Fujioka S, Yoshida S. Organ-specific expression of brassinosteroid-biosynthetic genes and distribution of endogenous brassinosteroids in Arabidopsis. Plant Physiol. 2003;131:287-97 pubmed
    ..In contrast, synthesis was limited in mature organs. Our observations are consistent with the idea that BRs function as the growth-promoting hormone in plants. ..
  41. Nagata N, Asami T, Yoshida S. Brassinazole, an inhibitor of brassinosteroid biosynthesis, inhibits development of secondary xylem in cress plants (Lepidium sativum). Plant Cell Physiol. 2001;42:1006-11 pubmed
    ..This result indicates that brassinosteroids function in xylem development in vivo. ..
  42. Mouchel C, Osmont K, Hardtke C. BRX mediates feedback between brassinosteroid levels and auxin signalling in root growth. Nature. 2006;443:458-61 pubmed
    ..BRX expression is strongly induced by auxin and mildly repressed by brassinolide, which means that BRX acts at the nexus of a feedback loop that maintains threshold brassinosteroid levels to permit optimal auxin action. ..
  43. Tanabe S, Ashikari M, Fujioka S, Takatsuto S, Yoshida S, Yano M, et al. A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant, dwarf11, with reduced seed length. Plant Cell. 2005;17:776-90 pubmed
    ..Multiple lines of evidence together suggest that the D11/CYP724B1 gene plays a role in BR synthesis and may be involved in the supply of 6-DeoxoTY and TY in the BR biosynthesis network in rice. ..
  44. Li J, Wen J, Lease K, Doke J, Tax F, Walker J. BAK1, an Arabidopsis LRR receptor-like protein kinase, interacts with BRI1 and modulates brassinosteroid signaling. Cell. 2002;110:213-22 pubmed
    ..Expression of a dominant-negative mutant allele of BAK1 causes a severe dwarf phenotype, resembling the phenotype of null bri1 alleles. These results indicate BAK1 is a component of BR signaling. ..
  45. Yan Z, Zhao J, Peng P, Chihara R, Li J. BIN2 functions redundantly with other Arabidopsis GSK3-like kinases to regulate brassinosteroid signaling. Plant Physiol. 2009;150:710-21 pubmed publisher
  46. Gampala S, Kim T, He J, Tang W, Deng Z, Bai M, et al. An essential role for 14-3-3 proteins in brassinosteroid signal transduction in Arabidopsis. Dev Cell. 2007;13:177-89 pubmed
    ..This study demonstrates that multiple mechanisms are required for BR regulation of gene expression and plant growth. ..
  47. Chono M, Honda I, Zeniya H, Yoneyama K, Saisho D, Takeda K, et al. A semidwarf phenotype of barley uzu results from a nucleotide substitution in the gene encoding a putative brassinosteroid receptor. Plant Physiol. 2003;133:1209-19 pubmed
    ..The uzu gene is being introduced into all hull-less barley cultivars in Japan as an effective dwarf gene for practical use, and this is the first report about an agronomically important mutation related to BRs. ..
  48. Zhao J, Peng P, Schmitz R, Decker A, Tax F, Li J. Two putative BIN2 substrates are nuclear components of brassinosteroid signaling. Plant Physiol. 2002;130:1221-9 pubmed
    ..We propose that BES1/BZR1 are two nuclear components of BR signaling that are negatively regulated by BIN2 through a phosphorylation-initiated process. ..
  49. Li J, Nagpal P, Vitart V, McMorris T, Chory J. A role for brassinosteroids in light-dependent development of Arabidopsis. Science. 1996;272:398-401 pubmed
    ..Thus, DET2 may encode a reductase in the brassinolide biosynthetic pathway, and brassinosteroids may constitute a distinct class of phytohormones with an important role in light-regulated development of higher plants. ..
  50. Wang L, Xu Y, Li J, Powell R, Xu Z, Chong K. Transgenic rice plants ectopically expressing AtBAK1 are semi-dwarfed and hypersensitive to 24-epibrassinolide. J Plant Physiol. 2007;164:655-64 pubmed
    ..On the other hand, the transgenic plants generated by overproducing AtBAK1 may potentially have agricultural applications because the dwarfed phenotype is generally resistant to lodging, while the fertility remains unaffected. ..
  51. Jonak C, Hirt H. Glycogen synthase kinase 3/SHAGGY-like kinases in plants: an emerging family with novel functions. Trends Plant Sci. 2002;7:457-61 pubmed
    ..Analysis of the Arabidopsis genome revealed the existence of ten GSK genes that fall into four distinct subfamilies. We discuss the functions and mechanisms of GSK action in plants and other organisms. ..
  52. Tiryaki I, Staswick P. An Arabidopsis mutant defective in jasmonate response is allelic to the auxin-signaling mutant axr1. Plant Physiol. 2002;130:887-94 pubmed
    ..This study demonstrates that in addition to auxin signaling, the AXR1 locus is involved in MeJA response, providing a mechanistic link between jasmonate and auxin-signaling pathways. ..
  53. Ibañes M, Fàbregas N, Chory J, Caño Delgado A. Brassinosteroid signaling and auxin transport are required to establish the periodic pattern of Arabidopsis shoot vascular bundles. Proc Natl Acad Sci U S A. 2009;106:13630-5 pubmed publisher
    ..Overall, this study demonstrates that auxin polar transport coupled to brassinosteroid signaling is required to determine the radial pattern of vascular bundles in shoots. ..