Functional characterization of Terminal Flower1 homolog in Cornus canadensis by genetic transformation

  • Xiang LiuEmail author
  • Jian Zhang
  • Deyu Xie
  • Robert G. Franks
  • Qiu-Yun (Jenny) XiangEmail author
Original Article


Key message

TFL1homologCorcanTFL1suppresses the initiation of inflorescence development and regulates the inflorescence morphology inCornus canadensis.


In flowering plants, there is a wide range of variation of inflorescence morphology. Despite the ecological and evolutionary importance, efforts devoted to the evolutionary study of the genetic basis of inflorescence morphology are far fewer compared to those on flower development. Our previous study on gene expression patterns suggested a CorTFL1–CorAP1 based model for the evolution of determinate umbels, heads, and mini dichasia from elongated inflorescences in Cornus. Here, we tested the function of CorcanTFL1 in regulating inflorescence development in Cornus canadensis through Agrobacterium-mediated transformation. We showed that transgenic plants overexpressing CorcanTFL1 displayed delayed or suppressed inflorescence initiation and development and extended periods of vegetative growth. Transgenic plants within which CorcanTFL1 had been down-regulated displayed earlier emergence of inflorescence and a reduction of bract and inflorescence sizes, conversions of leaves to bracts and axillary leaf buds to small inflorescences at the uppermost node bearing the inflorescence, or phyllotaxy changes of inflorescence branches and leaves from decussate opposite to spirally alternate. These observations support an important role of CorcanTFL1 in determining flowering time and the morphological destinies of leaves and buds at the node bearing the inflorescence. The evidence is in agreement with the predicted function of CorTFL1 from the gene expression model, supporting a key role of CorTFL1 in the evolutionary divergence of inflorescence forms in Cornus.


Cornus canadensis CorcanTFL1 Genetic transformation Inflorescence development Organ conversion 



We would like to thank NCSU Phytotron for providing the space of culturing C. canadensis source plants and transgenic plants. We are grateful to Ron Qu for discussion in vector construction and transformation experiments, to Ashley Yow for participating DNA extraction, to Na Li and Sarah Yim for assistance in culturing the plants in Phytotron, and to the anonymous reviewers for critical review of the manuscript and constructive comments. The study was supported by a National Science Foundation of the United States Grant (IOS-1024629).

Supplementary material

299_2019_2369_MOESM1_ESM.docx (14 kb)
Supplementary material 1 (DOCX 13 KB)
299_2019_2369_MOESM2_ESM.docx (13 kb)
Supplementary material 2 (DOCX 13 KB)
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Fig. S1 WT Cornus canadensis plants. a) Shoot termination and inflorescence development. b) An inflorescence with expanding bracts and opening flowers Supplementary material 3 (TIF 5928 KB)
299_2019_2369_MOESM4_ESM.tif (9.1 mb)
Fig. S2 Inflorescence morphology of transgenic plants. a) Morphology of inflorescences in a plant downregulating CorcanTFL1 by hairpin construct, supporting figure 4. b) Upregulation of CorcanLFY in leaves of transgenic plants derived from the transformation of CorcanLFY overexpression. c-d) Morphology of inflorescences of plants overexpressing CorcanLFY. The procedure of vector construction for CorcanLFY overexpression is the same as that of vector pH2GW7-CorcanTFL1w Supplementary material 4 (TIF 9143 KB)


  1. Ahn JH, Miller D, Winter VJ et al (2006) A divergent external loop confers antagonistic activity on floral regulators FT and TFL1. EMBO J 25:605–614CrossRefGoogle Scholar
  2. Amasino RM, Michaels SD (2010) The timing of flowering. Plant Physiol 154:516–520CrossRefGoogle Scholar
  3. Berbel A, Ferrándiz C, Hecht V et al (2012) VEGETATIVE1 is essential for development of the compound inflorescence in pea. Nat Commun 3:797CrossRefGoogle Scholar
  4. Bradley D, Carpenter R, Copsey L et al (1996) Control of inflorescence architecture in Antirrhinum. Nature 379:791CrossRefGoogle Scholar
  5. Chang S, Puryear J, Cairney J (1993) A simple and efficient method for isolating RNA from pine trees. Plant Mol Biol Rep 11:113–116CrossRefGoogle Scholar
  6. Chery (2016) RNA therapeutics: RNAi and antisense mechanisms and clinical applications. Postdoc J 4(7):35–50CrossRefGoogle Scholar
  7. Conti L, Bradley D (2007) TERMINAL FLOWER1 is a mobile signal controlling Arabidopsis architecture. Plant Cell 19:767–778CrossRefGoogle Scholar
  8. Feng CM, Qu R, Zhou LL et al (2009) Shoot regeneration of dwarf dogwood (Cornus canadensis L.) and morphological characterization of the regenerated plants. Plant Cell Tissue Organ Cult 97:27–37. CrossRefGoogle Scholar
  9. Feng C, Xiang QJ, Franks RG (2011) Phylogeny-based developmental analyses illuminate evolution of inflorescence architectures in dogwoods (Cornus s.l., Cornaceae). New Phytol 191:850–869CrossRefGoogle Scholar
  10. Feng CM, Liu X, Yu Y et al (2012) Evolution of bract development and B-class MADS box gene expression in petaloid bracts of Cornus s. l. (Cornaceae). New Phytol 196:631–643. CrossRefGoogle Scholar
  11. Gallavotti A, Barazesh S, Malcomber S et al (2008) sparse inflorescence1 encodes a monocot-specific YUCCA-like gene required for vegetative and reproductive development in maize. Proc Natl Acad Sci USA 105:15196–15201CrossRefGoogle Scholar
  12. Hanano S, Goto K (2011) Arabidopsis TERMINAL FLOWER1 is involved in the regulation of flowering time and inflorescence development through transcriptional repression. Plant Cell 23:3172–3184CrossRefGoogle Scholar
  13. Höfgen R, Willmitzer L (1988) Storage of competent cells for Agrobacterium transformation. Nucleic Acids Res 16:9877CrossRefGoogle Scholar
  14. Irish VF, Sussex IM (1990) Function of the apetala-1 gene during Arabidopsis floral development. Plant Cell 2:741–753CrossRefGoogle Scholar
  15. Itoh J, Hibara K, Kojima M et al (2012) Rice DECUSSATE controls phyllotaxy by affecting the cytokinin signaling pathway. Plant J 72:869–881CrossRefGoogle Scholar
  16. Johansson M, Staiger D (2015) Time to flower: interplay between photoperiod and the circadian clock. J Exp Bot 66:719–730. CrossRefGoogle Scholar
  17. Kardailsky I, Shukla VK, Ahn JH et al (1999) Activation tagging of the floral inducer FT. Science 286:1962–1965. CrossRefGoogle Scholar
  18. Leibfried A, To JPC, Busch W et al (2005) WUSCHEL controls meristem function by direct regulation of cytokinin-inducible response regulators. Nature 438:1172CrossRefGoogle Scholar
  19. Liljegren SJ, Gustafson-Brown C, Pinyopich A et al (1999) Interactions among APETALA1, LEAFY, and TERMINAL FLOWER1 specify meristem fate. Plant Cell 11:1007–1018CrossRefGoogle Scholar
  20. Lipardi C, Wei Q, Paterson BM (2001) RNAi as random degradative PCR: siRNA primers convert mRNA into dsRNAs that are degraded to generate new siRNAs. Cell 107:297–307CrossRefGoogle Scholar
  21. Lippman ZB, Cohen O, Alvarez JP et al (2008) The making of a compound inflorescence in tomato and related nightshades. PLoS Biol 6:e288CrossRefGoogle Scholar
  22. Liu J, Franks R, Feng CF et al (2013a) Characterization of the sequence and expression pattern of LFY homologs from dogwoods species (Cornus L.) with divergent inflorescence architectures. Ann Bot 112:1629–1641. CrossRefGoogle Scholar
  23. Liu X, Feng C-M, Franks R et al (2013b) Plant regeneration and genetic transformation of C. canadensis: a non-model plant appropriate for investigation of flower development in Cornus (Cornaceae). Plant Cell Rep 32:77–87CrossRefGoogle Scholar
  24. Liu X, Zhang J, Abuahmad A et al (2016) Analysis of two TFL1 homologs of dogwood species (Cornus L.) indicates functional conservation in control of transition to flowering. Planta 243:1129–1141CrossRefGoogle Scholar
  25. Liu X, Li L, Xiang QY(J) (2017) Down regulation of APETALA3 homolog resulted in defect of floral structure critical to explosive pollen release in Cornus canadensis. JSA 55:566–580Google Scholar
  26. Ma Q, Liu X, Franks RG, Xiang QY(J) (2017) Alterations of CorTFL1 and CorAP1 expression correlate with major evolutionary shifts of inflorescence architecture in Cornus (Cornaceae)–a proposed model for variation of closed inflorescence forms. New Phytol 216:519–535CrossRefGoogle Scholar
  27. Mandel MA, Gustafson-Brown C, Savidge B, Yanofsky MF (1992) Molecular characterization of the Arabidopsis floral homeotic gene APETALA1. Nature 360:273CrossRefGoogle Scholar
  28. Mimida N, Goto K, Kobayashi Y et al (2001) Functional divergence of the TFL1-like gene family in Arabidopsis revealed by characterization of a novel homologue. Genes Cells 6:327–336CrossRefGoogle Scholar
  29. Moyroud E, Minguet EG, Ott F et al (2011) Prediction of regulatory interactions from genome sequences using a biophysical model for the Arabidopsis LEAFY transcription factor. Plant Cell 23:1293–1306CrossRefGoogle Scholar
  30. Murashige T, Skoog F (1962) A revised medium for rapid growth and bio assays with tobacco tissue cultures. Physiol Plant 15:473–497CrossRefGoogle Scholar
  31. Périlleux C, Lobet G, Tocquin P (2014) Inflorescence development in tomato: gene functions within a zigzag model. Front Plant Sci 5:121Google Scholar
  32. Phillips KA, Skirpan AL, Liu X et al (2011) vanishing tassel2 encodes a grass-specific tryptophan aminotransferase required for vegetative and reproductive development in Maize. Plant Cell 23:550–566CrossRefGoogle Scholar
  33. Pnueli L, Carmel-Goren L, Hareven D et al (1998) The SELF-PRUNING gene of tomato regulates vegetative to reproductive switching of sympodial meristems and is the ortholog of CEN. and TFL1. Development 125:1979–1989Google Scholar
  34. Pnueli L, Gutfinger T, Hareven D et al (2001) Tomato SP-interacting proteins define a conserved signaling system that regulates shoot architecture and flowering. Plant Cell 13:2687–2702CrossRefGoogle Scholar
  35. Prusinkiewicz P, Erasmus Y, Lane B et al (2007) Evolution and development of inflorescence architectures. Science 316:1452–1456. CrossRefGoogle Scholar
  36. Ratcliffe OJ, Amaya I, Vincent CA et al (1998) A common mechanism controls the life cycle and architecture of plants. Development 125:1609–1615Google Scholar
  37. Romera-Branchat M, Andrés F, Coupland G (2014) Flowering responses to seasonal cues: what’s new? Curr Opin Plant Biol 21:120–127CrossRefGoogle Scholar
  38. Saurabh S, Vidyarthi AS, Prasad D (2014) RNA interference: concept to reality in crop improvement. Planta 239:543–564CrossRefGoogle Scholar
  39. Shannon S, Meeks-Wagner DR (1991) A mutation in the Arabidopsis TFL1 gene affects inflorescence meristem development. Plant Cell Online 3:877–892. CrossRefGoogle Scholar
  40. Wagner D (2017) Key developmental transitions during flower morphogenesis and their regulation. Curr Opin Genet Dev 45:44–50CrossRefGoogle Scholar
  41. Wang R, Albani MC, Vincent C et al (2011) Aa TFL1 confers an age-dependent response to vernalization in perennial Arabis alpina. Plant Cell 23:1307–1321CrossRefGoogle Scholar
  42. Wang Z, Yang R, Devisetty UK et al (2017) The divergence of flowering time modulated by FT/TFL1 is independent to their interaction and binding activities. Front Plant Sci 8:697CrossRefGoogle Scholar
  43. Weigel D, Alvarez J, Smyth DR et al (1992) LEAFY controls floral meristem identity in Arabidopsis. Cell 69:843–859CrossRefGoogle Scholar
  44. Wellmer F, Riechmann JL (2010) Gene networks controlling the initiation of flower development. Trends Genet 26:519–527CrossRefGoogle Scholar
  45. Wickland DP, Hanzawa Y (2015) The FLOWERING LOCUS T/TERMINAL FLOWER1 gene family: functional evolution and molecular mechanisms. Mol Plant 8:983–997CrossRefGoogle Scholar
  46. Winter CM, Austin RS, Blanvillain-Baufume S et al (2011) LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response. Dev Cell 20:430–443CrossRefGoogle Scholar
  47. Zhao Z, Andersen SU, Ljung K et al (2010) Hormonal control of the shoot stem-cell niche. Nature 465:1089CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Plant and Microbial BiologyNorth Carolina State UniversityRaleighUSA
  2. 2.State Key Laboratory of Systematic and Evolutionary Botany, Institute of BotanyChinese Academy of SciencesBeijingPeople’s Republic of China

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