The induction of flowering is a central event in the life cycle of plants. When timed correctly, it helps to ensure reproductive success, and therefore has adaptive value. Because of its importance, flowering is under the control of a complex genetic circuitry that integrates environmental and endogenous signals.
Markus Schmid 1150Genetic analyses initially suggested the existence of distinct, genetically defined pathways that regulate flowering in response to a specific input. Over the last years, however, it has become apparent that many important flowering time genes are not regulated by single inputs, but rather integrate multiple, often contradictory signals to control the induction of flowering. This provides plants with a certain developmental plasticity in their timing of the floral transition.
Picture1 880Figure 1: Genetic network regulating the expression of the FLOWERING LOCUS T (FT) gene in the leaf vasculature. The FT protein serves as a florigen, a long-distance signal that moves to the growing tip of the plant, the so-called shoot apical meristem, where it induces the formation of flowers.
Work in our group has so far mostly aimed to understand the precise mechanisms that govern flowering time. To this end we employ a combination of molecular biology, genetic, and high-throughput sequencing (ChIP-seq, RNA-seq) techniques to unravel the transcription factor network that integrates diverse environmental signals in the model plant Arabidopsis thaliana. More recently we have adopted the INTACT, which allows the isolation of nuclei from defined tissues and cell types, to increase the temporal and spatial resolution of our analyses (Fig. 2). A second focus of the group is directed at understanding how trehalose-6-phosphate (and sugar signals in general) are integrated into the canonical network that regulates flowering.

Picture2Figure 2: Establishing INTACT for the shoot apical meristem (SAM) of Arabidopsis thaliana. (A) During the transition to flowering the SAM undergoes a transition and starts producing flower primordial instead of leaves. (B) We have established INTACT (Deal & Henikoff, Dev. Cell, 2010) for the SAM to study the transcriptional and epigenetic process that control flowering in this important tissue

Publications list

  1. Arabidopsis RNA processing factor SERRATE regulates the transcription of intronless genes
    Elife 2018 Aug 28;7  [Epub ahead of print]
  2. PORCUPINE regulates development in response to temperature through alternative splicing
    Nat Plants. 2018, 4:534–539
  3. Role of BASIC PENTACYSTEINE transcription factors in a subset of cytokinin signaling responses
    PLANT JOURNAL, 95 (3):458-473
  4. WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity
    PLoS Genet. 2018 Jan 29;14(1):e1007177
  5. Role of BASIC PENTACYSTEIENE transcription factors in a sub-set of cytokinin signaling responses
    Plant J. 2018, 95(3):458-473
  6. WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity
    PLoS Genet. 2018, 14(1): e1007177
  7. Contribution of major FLM isoforms to temperature-dependent flowering in Arabidopsis thaliana
    J Exp Bot. 2017, 68 (18):5117-5127
  8. Temporal dynamics of gene expression and histone marks at the Arabidopsis shoot meristem during flowering
    Nat Commun. 2017, 8:15120
  9. A circRNA from SEPALLATA3 regulates splicing of its cognate mRNA through R-loop formation
    Nat Plants. 2017 Apr 18;3:17053
  10. Growth and development: Change is in the air: how plants modulate development in response to the environment
    Curr Opin Plant Biol. 2017 volume 35 (iv–vi)
  11. Integration of light and metabolic signals for stem cell activation at the shoot apical meristem
    Elife. 2016, e17023.[Epub ahead of print]
  12. A SAM oligomerization domain shapes the genomic binding landscape of the LEAFY transcription factor
    Nat Commun. 2016 Apr 21;7:11222
  13. Gibberellic acid signaling is required for ambient temperature-mediated induction of flowering in Arabidopsis thaliana
    Plant J. 2015, 84 (5):949-962
  14. Role of alternative pre-mRNA splicing in temperature signaling
    Curr Opin Plant Biol. 2015, 27:97-103
  15. A quantitative and dynamic model of the Arabidopsis flowering time gene regulatory network
    PLoS One 2015 10: e0116973
  16. Control of flowering by ambient temperature
    J Exp Bot 2015 66: 59-69
  17. Modulation of Ambient Temperature-Dependent Flowering in Arabidopsis thaliana by Natural Variation of FLOWERING LOCUS M
    PLoS Genet 2015 11: e1005588
  18. Profiling of embryonic nuclear vs. cellular RNA in Arabidopsis thaliana
    Genom Data 2015 4: 96-98
  19. Cell type-specific transcriptome analysis in the early Arabidopsis thaliana embryo
    Development 2014 141: 4831-4840
  20. Reciprocal responses in the interaction between Arabidopsis and the cell-content-feeding chelicerate herbivore spider mite
    Plant Physiol 2014 164: 384-399
  21. Regulation of flowering by trehalose-6-phosphate signaling in Arabidopsis thaliana
    Science 2013 339: 704-707
  22. Regulation of temperature-responsive flowering by MADS-box transcription factor repressors
    Science 2013 342: 628-632
  23. Temperature-dependent regulation of flowering by antagonistic FLM variants
    Nature 2013 503: 414-417
  24. Characterization of SOC1's central role in flowering by the identification of its upstream and downstream regulators
    Plant Physiol 2012 160: 433-449
  25. Genome-wide binding-site analysis of REVOLUTA reveals a link between leaf patterning and light-mediated growth responses
    Plant J 2012 72: 31-42
  26. Gibberellin regulates the Arabidopsis floral transition through miR156-targeted SQUAMOSA promoter binding-like transcription factors
    Plant Cell 2012 24: 3320-3332
  27. Spatial control of flowering by DELLA proteins in Arabidopsis thaliana
    Development 2012 139: 4072-4082
  28. Synteny-based mapping-by-sequencing enabled by targeted enrichment
    Plant J 2012 71: 517-526
  29. The end of innocence: flowering networks explode in complexity
    Curr Opin Plant Biol 2012 15: 45-50
  30. The floral homeotic protein APETALA2 recognizes and acts through an AT-rich sequence element
    Development 2012 139: 1978-1986
  31. Prediction of regulatory interactions from genome sequences using a biophysical model for the Arabidopsis LEAFY transcription factor
    Plant Cell 2011 23: 1293-1306
  32. Regulation of flowering time: all roads lead to Rome
    Cell Mol Life Sci 2011 68: 2013-2037
  33. The control of developmental phase transitions in plants
    Development 2011 138: 4117-4129
  34. Trehalose-6-phosphate: connecting plant metabolism and development
    Front Plant Sci 2011 2: 70
  35. Control of lateral organ development and flowering time by the Arabidopsis thaliana MADS-box Gene AGAMOUS-LIKE6
    Plant J 2010 62: 807-816
  36. MONOPTEROS controls embryonic root initiation by regulating a mobile transcription factor
    Nature 2010 464: 913-916
  37. Orchestration of the floral transition and floral development in Arabidopsis by the bifunctional transcription factor APETALA2
    Plant Cell 2010 22: 2156-2170
  38. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana
    BMC Plant Biol 2010 10: 285
  39. Just say no: floral repressors help Arabidopsis bide the time
    Curr Opin Plant Biol 2009 12: 580-586
  40. Repression of flowering by the miR172 target SMZ
    PLoS Biol 2009 7: e1000148
  41. Auxin responses in mutants of the Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC9 signalosome
    Plant Physiol 2008 147: 1369-1379
  42. KDEL-tailed cysteine endopeptidases involved in programmed cell death, intercalation of new cells, and dismantling of extensin scaffolds
    Am J Bot 2008 95: 1049-1062
  43. The Arabidopsis COP9 signalosome is essential for G2 phase progression and genomic stability
    Development 2008 135: 2013-2022
  44. Distinct expression patterns of natural antisense transcripts in Arabidopsis
    Plant Physiol 2007 144: 1247-1255
  45. Export of FT protein from phloem companion cells is sufficient for floral induction in Arabidopsis
    Curr Biol 2007 17: 1055-1060
  46. A gene expression map of Arabidopsis thaliana development
    Nat Genet 2005 37: 501-506
  47. Diversity of flowering responses in wild Arabidopsis thaliana strains
    PLoS Genet 2005 1: 109-118
  48. Integration of spatial and temporal information during floral induction in Arabidopsis
    Science 2005 309: 1056-1059
  49. Specific effects of microRNAs on the plant transcriptome
    Dev Cell 2005 8: 517-527
  50. AthPEX10, a nuclear gene essential for peroxisome and storage organelle formation during Arabidopsis embryogenesis
    Proc Natl Acad Sci U S A 2003 100: 9626-9631
  51. Dissection of floral induction pathways using global expression analysis
    Development 2003 130: 6001-6012
  52. Genome-wide insertional mutagenesis of Arabidopsis thaliana
    Science 2003 301: 653-657
  53. Ricinosomes: an organelle for developmentally regulated programmed cell death in senescing plant tissues
    Naturwissenschaften 2001 88: 49-58
  54. The ricinosomes of senescing plant tissue bud from the endoplasmic reticulum
    Proc Natl Acad Sci U S A 2001 98: 5353-5358
  55. Programmed cell death in castor bean endosperm is associated with the accumulation and release of a cysteine endopeptidase from ricinosomes
    Proc Natl Acad Sci U S A 1999 96: 14159-14164
  56. A cysteine endopeptidase with a C-terminal KDEL motif isolated from castor bean endosperm is a marker enzyme for the ricinosome, a putative lytic compartment
    Planta 1998 206: 466-475
  57. The plant PTS1 receptor: similarities and differences to its human and yeast counterparts
    Plant J 1998 16: 453-464