Defensin-like polypeptide LUREs are pollen tube attractants secreted from synergid cells


For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoattractants derived from target ovules1. However, there has been no convincing evidence of any particular molecule being the true attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance1,2,3. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoattractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the attractants derived from the synergid cells of T. fournieri.

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Figure 1: Identification and expression analysis of major CRPs of the synergid cell.
Figure 2: In vitro pollen tube attraction assay using recombinant CRPs.
Figure 3: Microinjection of MO antisense oligos for LUREs.


  1. 1

    Higashiyama, T. & Hamamura, Y. Gametophytic pollen tube guidance. Sex. Plant Reprod. 21, 17–26 (2008)

    Article  Google Scholar 

  2. 2

    Higashiyma, T. et al. Pollen tube attraction by the synergid cell. Science 293, 1480–1483 (2001)

    ADS  Article  Google Scholar 

  3. 3

    Punwani, J. A. & Drews, G. N. Development and function of the synergid cell. Sex. Plant Reprod. 21, 7–15 (2008)

    Article  Google Scholar 

  4. 4

    Higashiyama, T. et al. Species preferentiality of the pollen tube attractant derived from the synergid cell of Torenia fournieri. Plant Physiol. 142, 481–491 (2006)

    CAS  Article  Google Scholar 

  5. 5

    Imre, K. & Kristof, Z. Isolation and osmotic relations of developing megagametophytes of Torenia fournieri. Sex. Plant Reprod. 12, 152–157 (1999)

    Article  Google Scholar 

  6. 6

    Silverstein, K. A. et al. Small cysteine-rich peptides resembling antimicrobial peptides have been under-predicted in plants. Plant J. 51, 262–280 (2007)

    CAS  Article  Google Scholar 

  7. 7

    Punwani, J. A., Rabiger, D. S. & Drews, G. N. MYB98 positively regulates a battery of synergid-expressed genes encoding filiform apparatus-localized proteins. Plant Cell 19, 2557–2568 (2007)

    CAS  Article  Google Scholar 

  8. 8

    Jones-Rhoades, M. W., Borevitz, J. O. & Preuss, D. Genome-wide expression profiling of the Arabidopsis female gametophyte identifies families of small, secreted proteins. PLoS Genet. 3, 1848–1861 (2007)

    CAS  Article  Google Scholar 

  9. 9

    Cordts, S. et al. ZmES genes encode peptides with structural homology to defensins and are specifically expressed in the female gametophyte of maize. Plant J. 25, 103–114 (2001)

    CAS  Article  Google Scholar 

  10. 10

    Yang, H., Kaur, N., Kiriakopolos, S. & McCormick, S. EST generation and analyses towards identifying female gametophyte-specific genes in Zea mays L. Planta 224, 1004–1014 (2006)

    CAS  Article  Google Scholar 

  11. 11

    Kasahara, R. D. et al. MYB98 is required for pollen tube guidance and synergid cell differentiation in Arabidopsis. Plant Cell 17, 2981–2992 (2005)

    CAS  Article  Google Scholar 

  12. 12

    Silverstein, K. A., Graham, M. A., Paape, T. D. & VandenBosch, K. A. Genome organization of more than 300 defensin-like genes in Arabidopsis. Plant Physiol. 138, 600–610 (2005)

    CAS  Article  Google Scholar 

  13. 13

    Cornet, B. et al. Refined three-dimensional solution structure of insect defensin A. Structure 3, 435–448 (1995)

    CAS  Article  Google Scholar 

  14. 14

    Yount, N. Y. & Yeaman, M. R. Multidimensional signatures in antimicrobial peptides. Proc. Natl Acad. Sci. USA 101, 7363–7368 (2004)

    ADS  CAS  Article  Google Scholar 

  15. 15

    Higashiyama, T., Kuroiwa, H., Kawano, S. & Kuroiwa, T. Guidance in vitro of the pollen tube to the naked embryo sac of Torenia fournieri. Plant Cell 10, 2019–2031 (1998)

    CAS  Article  Google Scholar 

  16. 16

    Takayama, S. et al. Direct ligand–receptor complex interaction controls Brassica self-incompatibility. Nature 413, 534–538 (2001)

    ADS  CAS  Article  Google Scholar 

  17. 17

    Karkare, S. & Bhatnagar, D. Promising nucleic acid analogs and mimics: characteristic features and applications of PNA, LNA, and morpholino. Appl. Microbiol. Biotechnol. 71, 575–586 (2006)

    CAS  Article  Google Scholar 

  18. 18

    Han, Y. Z., Huang, B. Q., Zee, S. Y. & Yuan, M. Symplastic communication between the central cell and the egg apparatus cells in the embryo sac of Torenia fournieri Lind. before and during fertilization. Planta 211, 158–162 (2000)

    CAS  Article  Google Scholar 

  19. 19

    Kim, S. et al. Chemocyanin, a small basic protein from the lily stigma, induces pollen tube chemotropism. Proc. Natl Acad. Sci. USA 100, 16125–16130 (2003)

    ADS  CAS  Article  Google Scholar 

  20. 20

    Wolters-Arts, M., Lush, W. M. & Mariani, C. Lipids are required for directional pollen-tube growth. Nature 392, 818–821 (1998)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Palanivelu, R., Brass, L., Edlund, A. F. & Preuss, D. Pollen tube growth and guidance is regulated by POP2, an Arabidopsis gene that controls GABA levels. Cell 114, 47–59 (2003)

    CAS  Article  Google Scholar 

  22. 22

    Márton, M. L., Cordts, S., Broadhvest, J. & Dresselhaus, T. Micropylar pollen tube guidance by EGG APPARATUS 1 of maize. Science 307, 573–576 (2005)

    ADS  Article  Google Scholar 

  23. 23

    Park, S. Y. et al. A lipid transfer-like protein is necessary for lily pollen tube adhesion to an in vitro stylar matrix. Plant Cell 12, 151–163 (2000)

    CAS  Article  Google Scholar 

  24. 24

    Doughty, J. et al. PCP-A1, a defensin-like Brassica pollen coat protein that binds the S locus glycoprotein, is the product of gametophytic gene expression. Plant Cell 10, 1333–1347 (1998)

    CAS  Article  Google Scholar 

  25. 25

    Cheung, A. Y. & Wu, H. M. Pollen tube guidance—right on target. Science 293, 1441–1442 (2001)

    CAS  Article  Google Scholar 

  26. 26

    Higashiyama, T. The synergid cell: attractor and acceptor of the pollen tube for double fertilization. J. Plant Res. 115, 149–160 (2002)

    Article  Google Scholar 

  27. 27

    Márton, M. L. & Dresselhaus, T. A comparison of early molecular fertilization mechanisms in animals and flowering plants. Sex. Plant Reprod. 21, 37–52 (2008)

    Article  Google Scholar 

  28. 28

    Berger, F., Hamamura, Y., Ingouff, M. & Higashiyama, T. Double fertilization — caught in the act. Trends Plant Sci. 13, 437–443 (2008)

    CAS  Article  Google Scholar 

  29. 29

    Escobar-Restrepo, J. M. et al. The FERONIA receptor-like kinase mediates male–female interactions during pollen tube reception. Science 317, 656–660 (2007)

    ADS  CAS  Article  Google Scholar 

  30. 30

    Sprunck, S. et al. The transcript composition of egg cells changes significantly following fertilization in wheat (Triticum aestivum L.). Plant J. 41, 660–672 (2005)

    CAS  Article  Google Scholar 

  31. 31

    Higashiyama, T. & Inatsugi, R. Comparative analyses of biological models used in the study of pollen tube growth. Plant Cell Monogr. 3, 265–286 (2006)

    CAS  Article  Google Scholar 

  32. 32

    Ingouff, M. et al. Distinct dynamics of HISTONE3 variants between the two fertilization products in plants. Curr. Biol. 17, 1032–1037 (2007)

    CAS  Article  Google Scholar 

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We thank T. Suzuki for help with the analysis of the EST sequences, S. Takayama for providing chemically synthesized and refolded SP11 peptides, W. Uchida for checking the diameter of the glass needles for microinjection by scanning electron microscopy and N. Iwata for assistance in preparing plant materials. This work was supported in part by a Grant-in-Aid for Young Scientists (Start-up), Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan (20870020 to M.M.K.); a Grant-in-Aid for Creative Scientific Research, MEXT, Japan (18GS0314-01 to N.S.); a grant from Yamada Science Foundation, Japan (to T.H.); a Grant-in-Aid for Scientific Research (B), MEXT, Japan (19370017 to T.H.); a Grant-in-Aid for Scientific Research on Priority Areas (18075004 to T.H.), and PRESTO project, Japan Science and Technology Agency, Japan (to T.H.).

Author Contributions S.O., N.S. and T.H. developed methods to purify and assay recombinant LUREs. H.Tsutsui and T.H. developed methods for the microinjection of the MO oligos and performed the RT–PCR analysis. K.S., N.S. and M.M.K. developed immunological methods to detect LUREs. T.H., S.S. and T.D. constructed the cDNA library of the synergid cell of T. fournieri and directed the EST analysis. H.Takeuchi., R.Y., R.D.K., Y.H., A.M., D.S., N.K., T.S., K.I., K.O., M.M., H.N. and M.M.K. assembled and analysed the EST sequences. S.N. constructed expression vectors and purified recombinant LUREs. T.K., A.N., T.D., M.M.K., N.S. and T.H. contributed to the experimental design. T.H. directed the project and wrote the paper with input from co-authors.

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Correspondence to Tetsuya Higashiyama.

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This file contains Supplementary Figures 1-3 with Legends, Supplementary Tables 1-4 and the Legend for Supplementary Movie 1. (PDF 6881 kb)

Supplementary Movie 1

This movie file shows in vitro attraction assay using a pipette (see file s1 for full legend). (AVI 26776 kb)

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Okuda, S., Tsutsui, H., Shiina, K. et al. Defensin-like polypeptide LUREs are pollen tube attractants secreted from synergid cells. Nature 458, 357–361 (2009).

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