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A small-molecule screen identifies new functions for the plant hormone strigolactone


Parasitic weeds of the genera Striga and Orobanche are considered the most damaging agricultural agents in the developing world. An essential step in parasitic seed germination is sensing a group of structurally related compounds called strigolactones that are released by host plants. Although this makes strigolactone synthesis and action a major target of biotechnology, little fundamental information is known about this hormone. Chemical genetic screening using Arabidopsis thaliana as a platform identified a collection of related small molecules, cotylimides, which perturb strigolactone accumulation. Suppressor screens against select cotylimides identified light-signaling genes as positive regulators of strigolactone levels. Molecular analysis showed strigolactones regulate the nuclear localization of the COP1 ubiquitin ligase, which in part determines the levels of light regulators such as HY5. This information not only uncovers new functions for strigolactones but was also used to identify rice cultivars with reduced capacity to germinate parasitic seed.

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Figure 1: Structures and action of CTL compounds.
Figure 2: Strigolactone mutants are less sensitive to CTL-VI.
Figure 3: PΦB synthesis mutants have reduced germination and strigolactone levels.
Figure 4: Strigolactones inhibit hypocotyl growth.
Figure 5: Strigolactones cause accumulation of HY5 protein.
Figure 6: Strigolactones reduce COP1 nuclear localization.
Figure 7: Strigolactones can mimic light-adapted growth.
Figure 8: Model of strigolactone signaling.


  1. Santner, A. & Estelle, M. Recent advances and emerging trends in plant hormone signalling. Nature 459, 1071–1078 (2009).

    Article  CAS  PubMed  Google Scholar 

  2. Sakamoto, T. Phytohormones and rice crop yield: strategies and opportunities for genetic improvement. Transgenic Res. 15, 399–404 (2006).

    Article  CAS  PubMed  Google Scholar 

  3. Park, S.Y. et al. Abscisic acid inhibits type 2C protein phosphatases via the PYR/PYL family of START proteins. Science 324, 1068–1071 (2009).

    CAS  PubMed Central  PubMed  Google Scholar 

  4. Wang, Z.Y. et al. Nuclear-localized BZR1 mediates brassinosteroid-induced growth and feedback suppression of brassinosteroid biosynthesis. Dev. Cell 2, 505–513 (2002).

    Article  CAS  PubMed  Google Scholar 

  5. Savaldi-Goldstein, S. et al. New auxin analogs with growth-promoting effects in intact plants reveal a chemical strategy to improve hormone delivery. Proc. Natl. Acad. Sci. USA 105, 15190–15195 (2008).

    Article  CAS  PubMed  Google Scholar 

  6. Stirnberg, P., van De Sande, K. & Leyser, H.M. MAX1 and MAX2 control shoot lateral branching in Arabidopsis. Development 129, 1131–1141 (2002).

    CAS  PubMed  Google Scholar 

  7. Booker, J. et al. MAX3/CCD7 is a carotenoid cleavage dioxygenase required for the synthesis of a novel plant signaling molecule. Curr. Biol. 14, 1232–1238 (2004).

    Article  CAS  PubMed  Google Scholar 

  8. Gomez-Roldan, V. et al. Strigolactone inhibition of shoot branching. Nature 455, 189–194 (2008).

    Article  CAS  PubMed  Google Scholar 

  9. Umehara, M. et al. Inhibition of shoot branching by new terpenoid plant hormones. Nature 455, 195–200 (2008).

    Article  CAS  PubMed  Google Scholar 

  10. Akiyama, K., Matsuzaki, K. & Hayashi, H. Plant sesquiterpenes induce hyphal branching in arbuscular mycorrhizal fungi. Nature 435, 824–827 (2005).

    Article  CAS  PubMed  Google Scholar 

  11. Govindarajulu, M. et al. Nitrogen transfer in the arbuscular mycorrhizal symbiosis. Nature 435, 819–823 (2005).

    Article  CAS  Google Scholar 

  12. Joel, D.M. et al. Biology and management of weedy root parasites. Hortic. Rev. (Am. Soc. Hortic. Sci.) 33, 267–349 (2007).

    CAS  Google Scholar 

  13. López-Ráez, J.A. et al. Strigolactones: ecological significance and use as a target for parasitic plant control. Pest Manag. Sci. 65, 471–477 (2009).

    Article  PubMed  Google Scholar 

  14. Scholes, J.D. & Press, M.C. Striga infestation of cereal crops - an unsolved problem in resource limited agriculture. Curr. Opin. Plant Biol. 11, 180–186 (2008).

    Article  Google Scholar 

  15. Humphrey, A.J., Galster, A.M. & Beale, M.H. Strigolactones in chemical ecology: waste products or vital allelochemicals? Nat. Prod. Rep. 23, 592–614 (2006).

    Article  CAS  PubMed  Google Scholar 

  16. Finkelstein, R. et al. Molecular aspects of seed dormancy. Annu. Rev. Plant Biol. 59, 387–415 (2008).

    Article  CAS  Google Scholar 

  17. Seo, M. et al. Interaction of light and hormone signals in germinating seeds. Plant Mol. Biol. 69, 463–472 (2009).

    Article  CAS  PubMed  Google Scholar 

  18. Gazzarrini, S. et al. The transcription factor FUSCA3 controls developmental timing in Arabidopsis through the hormones gibberellin and abscisic acid. Dev. Cell 7, 373–385 (2004).

    Article  CAS  Google Scholar 

  19. Huq, E. et al. Phytochrome-interacting factor 1 is a critical bHLH regulator of chlorophyll biosynthesis. Science 305, 1937–1941 (2004).

    Article  CAS  PubMed  Google Scholar 

  20. Franklin, K.A. et al. The signal transducing photoreceptors of plants. Int. J. Dev. Biol. 49, 653–664 (2005).

    Article  CAS  Google Scholar 

  21. Nott, A. et al. Plastid-to-nucleus retrograde signaling. Annu. Rev. Plant Biol. 57, 739–759 (2006).

    Article  CAS  PubMed  Google Scholar 

  22. Muramoto, T. et al. The Arabidopsis photomorphogenic mutant hy1 is deficient in phytochrome chromophore biosynthesis as a result of a mutation in plastid heme oxygenase. Plant Cell 11, 335–348 (1999).

    Article  CAS  PubMed  Google Scholar 

  23. Davis, S.J. et al. The Arabidopsis thaliana HY1 locus, required for phytochrome-chromophore biosynthesis, encodes a protein related to heme oxygenases. Proc. Natl. Acad. Sci. USA 96, 6541–6546 (1999).

    Article  CAS  PubMed  Google Scholar 

  24. Kohchi, T. et al. The Arabidopsis HY2 gene encodes phytochromobilin synthase, a ferredoxin-dependent biliverdin reductase. Plant Cell 13, 425–436 (2001).

    Article  CAS  PubMed  Google Scholar 

  25. Izawa, T. et al. Phytochromes confer the photoperiodic control of flowering in rice (a short-day plant). Plant J. 22, 391–399 (2000).

    Article  CAS  PubMed  Google Scholar 

  26. Shen, H. et al. The F-box protein MAX2 functions as a positive regulator of photomorphogenesis in Arabidopsis. Plant Physiol. 145, 1471–1483 (2007).

    Article  CAS  PubMed  Google Scholar 

  27. Ang, L.H. et al. Molecular interaction between COP1 and HY5 defines a regulatory switch for light control of Arabidopsis development. Mol. Cell 1, 213–222 (1998).

    Article  CAS  PubMed  Google Scholar 

  28. Osterlund, M.T. et al. Targeted destabilization of HY5 during light-regulated development of Arabidopsis. Nature 405, 462–466 (2000).

    Article  CAS  PubMed  Google Scholar 

  29. von Arnim, A.G. & Deng, X.-W. Light inactivation of Arabidopsis photomorphogenic repressor COP1 involves a cell-specific regulation of its nucleocytoplasmic partitioning. Cell 79, 1035–1045 (1994).

    Article  CAS  PubMed  Google Scholar 

  30. Yi, C. & Deng, X.W. COP1 - from plant photomorphogenesis to mammalian tumorigenesis. Trends Cell Biol. 15, 618–625 (2005).

    Article  CAS  PubMed  Google Scholar 

  31. Goldwasser, Y. et al. Production of strigolactones by Arabidopsis thaliana responsible for Orobanche aegyptiaca seed germination. Plant Growth Regul. 55, 21–28 (2008).

    Article  CAS  Google Scholar 

  32. Murashige, T. & Skoog, F. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473–497 (1962).

    Article  CAS  Google Scholar 

  33. Clough, S.J. & Bent, A.F. Floral dip: a simplified method for Agrobacterium-mediated transformation in Arabidopsis thaliana. Plant J. 16, 735–743 (1998).

    Article  CAS  PubMed  Google Scholar 

  34. Stirnberg, P. et al. MAX2 participates in an SCF complex which acts locally at the node to suppress shoot branching. Plant J. 50, 80–94 (2007).

    Article  CAS  PubMed  Google Scholar 

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We thank D. Desveaux and S. Lumba for helpful discussion. We also thank the following researchers and the Ohio State Stock Center for providing materials: S.R. Cutler (Univ. California, Riverside), ABRC (T-DNA insertion lies); O. Leyser (Univ. York) (max1-1, max2-1, max3-9); T. Kohchi (Kyoto Univ.) (hy2-105); T. Sakai (RIKEN) (cry1 cry2); Y. Yamauchi, T. Izawa (Japanese National Institute of Agrobiological Sciences) and M. Nakazono (Univ. of Tokyo) (rice strains); M. Umehara (RIKEN) (rice instructions); A.G.T. Babiker (Sudan University of Science and Technology) (Striga hermonthica); M. Goldwasser (Hebrew Univ.) (Orobanche aegyptiaca); K. Yoneyama (Utsunomiya Univ.) (GR24); K. Shirasu and S. Yoshida (RIKEN) (Striga instructions); X.W. Deng (Yale Univ.) (HY5 antibody). We thank K. Akiyama (Osaka Prefecture Univ.) for the internal standard of 2′-epi-5DS.

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Y.T. performed the majority of the wet lab experiments with guidance from P.M. and E.N. D.V. and S.T. performed western blot analysis. A.H. contributed to strigolactone measurements in rice with guidance from S.Y. and Y.K. The project was conceived by Y.T. and P.M. and the manuscript written by P.M.

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Correspondence to Peter McCourt.

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Tsuchiya, Y., Vidaurre, D., Toh, S. et al. A small-molecule screen identifies new functions for the plant hormone strigolactone. Nat Chem Biol 6, 741–749 (2010).

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