Strigolactones (SLs) are a class of phytohormones and rhizosphere signaling compounds with high structural diversity. Three enzymes, carotenoid isomerase DWARF27 and carotenoid cleavage dioxygenases CCD7 and CCD8, were previously shown to convert all-trans-β-carotene to carlactone (CL), the SL precursor. However, how CL is metabolized to SLs has remained elusive. Here, by reconstituting the SL biosynthetic pathway in Nicotiana benthamiana, we show that a rice homolog of Arabidopsis MORE AXILLARY GROWTH 1 (MAX1), encodes a cytochrome P450 CYP711 subfamily member that acts as a CL oxidase to stereoselectively convert CL into ent-2′-epi-5-deoxystrigol (B-C lactone ring formation), the presumed precursor of rice SLs. A protein encoded by a second rice MAX1 homolog then catalyzes the conversion of ent-2′-epi-5-deoxystrigol to orobanchol. We therefore report that two members of CYP711 enzymes can catalyze two distinct steps in SL biosynthesis, identifying the first enzymes involved in B-C ring closure and a subsequent structural diversification step of SLs.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Umehara, M. et al. Inhibition of shoot branching by new terpenoid plant hormones. Nature 455, 195–200 (2008).
Gomez-Roldan, V. et al. Strigolactone inhibition of shoot branching. Nature 455, 189–194 (2008).
Ruyter-Spira, C., Al-Babili, S., van der Krol, S. & Bouwmeester, H. The biology of strigolactones. Trends Plant Sci. 18, 72–83 (2013).
Cook, C.E., Whichard, L.P., Turner, B., Wall, M.E. & Egley, G.H. Germination of witchweed (Striga lutea lour.): isolation and properties of a potent stimulant. Science 154, 1189–1190 (1966).
Akiyama, K., Matsuzaki, K. & Hayashi, H. Plant sesquiterpenes induce hyphal branching in arbuscular mycorrhizal fungi. Nature 435, 824–827 (2005).
Xie, X., Yoneyama, K. & Yoneyama, K. The strigolactone story. Annu. Rev. Phytopathol. 48, 93–117 (2010).
Xie, X. et al. Confirming stereochemical structures of strigolactones produced by rice and tobacco. Mol. Plant 6, 153–163 (2013).
Zwanenburg, B. & Pospisil, T. Structure and activity of strigolactones: new plant hormones with a rich future. Mol. Plant 6, 38–62 (2013).
Rani, K., Zwanenburg, B., Sugimoto, Y., Yoneyama, K. & Bouwmeester, H.J. Biosynthetic considerations could assist the structure elucidation of host plant produced rhizosphere signalling compounds (strigolactones) for arbuscular mycorrhizal fungi and parasitic plants. Plant Physiol. Biochem. 46, 617–626 (2008).
Yoneyama, K., Ruyter-Spira, C. & Bouwmeester, H. Induction of Germination (Springer-Verlag, Berlin, Heidelberg, 2013).
Yoneyama, K., Xie, X. & Takeuchi, Y. Strigolactones: structures and biological activities. Pest Manag. Sci. 65, 467–470 (2009).
Matusova, R. et al. The strigolactone germination stimulants of the plant-parasitic Striga and Orobanche spp. are derived from the carotenoid pathway. Plant Physiol. 139, 920–934 (2005).
Lin, H. et al. DWARF27, an iron-containing protein required for the biosynthesis of strigolactones, regulates rice tiller bud outgrowth. Plant Cell 21, 1512–1525 (2009).
Alder, A. et al. The path from β-carotene to carlactone, a strigolactone-like plant hormone. Science 335, 1348–1351 (2012).
Bruno, M. et al. On the substrate- and stereospecificity of the plant carotenoid cleavage dioxygenase 7. FEBS Lett. 588, 1802–1807 (2014).
Seto, Y. et al. Carlactone is an endogenous biosynthetic precursor for strigolactones. Proc. Natl. Acad. Sci. USA 111, 1640–1645 (2014).
Kohlen, W. et al. Strigolactones are transported through the xylem and play a key role in shoot architectural response to phosphate deficiency in nonarbuscular mycorrhizal host Arabidopsis. Plant Physiol. 155, 974–987 (2011).
Booker, J. et al. MAX1 encodes a cytochrome P450 family member that acts downstream of MAX3/4 to produce a carotenoid-derived branch-inhibiting hormone. Dev. Cell 8, 443–449 (2005).
Scaffidi, A. et al. Carlactone-independent seedling morphogenesis in Arabidopsis. Plant J. 76, 1–9 (2013).
Challis, R.J., Hepworth, J., Mouchel, C., Waites, R. & Leyser, O. A role for MORE AXILLARY GROWTH1 (MAX1) in evolutionary diversity in strigolactone signaling upstream of MAX2. Plant Physiol. 161, 1885–1902 (2013).
Böttcher, C. et al. The multifunctional enzyme CYP71B15 (PHYTOALEXIN DEFICIENT3) converts cysteine-indole-3-acetonitrile to camalexin in the indole-3-acetonitrile metabolic network of Arabidopsis thaliana. Plant Cell 21, 1830–1845 (2009).
Mizutani, M. & Ohta, D. Diversification of P450 genes during land plant evolution. Annu. Rev. Plant Biol. 61, 291–315 (2010).
de Vetten, N. et al. A cytochrome b5 is required for full activity of flavonoid 3′,5′-hydroxylase, a cytochrome P450 involved in the formation of blue flower colors. Proc. Natl. Acad. Sci. USA 96, 778–783 (1999).
Batard, Y. et al. Increasing expression of P450 and P450-reductase proteins from monocots in heterologous systems. Arch. Biochem. Biophys. 379, 161–169 (2000).
Goldwasser, Y., Yoneyama, K., Xie, X.A. & Yoneyama, K. Production of strigolactones by Arabidopsis thaliana responsible for Orobanche aegyptiaca seed germination. Plant Growth Regul. 55, 21–28 (2008).
Cardoso, C. et al. Natural variation of rice strigolactone biosynthesis is associated with the deletion of two MAX1 orthologs. Proc. Natl. Acad. Sci. USA 111, 2379–2384 (2014).
Boyer, F.D. et al. Structure-activity relationship studies of strigolactone-related molecules for branching inhibition in garden pea: molecule design for shoot branching. Plant Physiol. 159, 1524–1544 (2012).
Nomura, S., Nakashima, H., Mizutani, M., Takikawa, H. & Sugimoto, Y. Structural requirements of strigolactones for germination induction and inhibition of Striga gesnerioides seeds. Plant Cell Rep. 32, 829–838 (2013).
Akiyama, K., Ogasawara, S., Ito, S. & Hayashi, H. Structural requirements of strigolactones for hyphal branching in AM fungi. Plant Cell Physiol. 51, 1104–1117 (2010).
Ting, H.M. et al. The metabolite chemotype of Nicotiana benthamiana transiently expressing artemisinin biosynthetic pathway genes is a function of CYP71AV1 type and relative gene dosage. New Phytol. 199, 352–366 (2013).
Pompon, D., Louerat, B., Bronine, A. & Urban, P. Yeast expression of animal and plant P450s in optimized redox environments. Methods Enzymol. 272, 51–64 (1996).
Cankar, K. et al. A chicory cytochrome P450 mono-oxygenase CYP71AV8 for the oxidation of (+)-valencene. FEBS Lett. 585, 178–182 (2011).
van Engelen, F.A. et al. Pbinplus—an improved plant transformation vector based on Pbin19. Transgenic Res. 4, 288–290 (1995).
Gietz, D., St Jean, A., Woods, R.A. & Schiestl, R.H. Improved method for high efficiency transformation of intact yeast cells. Nucleic Acids Res. 20, 1425 (1992).
Bradford, M.M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72, 248–254 (1976).
Voinnet, O., Rivas, S., Mestre, P. & Baulcombe, D. An enhanced transient expression system in plants based on suppression of gene silencing by the p19 protein of tomato bushy stunt virus. Plant J. 33, 949–956 (2003).
Alder, A., Holdermann, I., Beyer, P. & Al-Babili, S. Carotenoid oxygenases involved in plant branching catalyse a highly specific conserved apocarotenoid cleavage reaction. Biochem. J. 416, 289–296 (2008).
Reizelman, A. & Zwanenburg, B. Synthesis of the germination stimulants (±)-orobanchol and (±)-strigol via an allylic rearrangement. Synthesis,1952–1955 (2000).
Reizelman, A., Scheren, M., Nefkens, G.H.L. & Zwanenburg, B. Synthesis of all eight stereoisomers of the germination stimulant strigol. Synthesis, 1944–1951 (2000).
Eswar, N., Eramian, D., Webb, B., Shen, M.Y. & Sali, A. Protein structure modeling with MODELLER. Methods Mol. Biol. 426, 145–159 (2008).
Williams, P.A. et al. Crystal structures of human cytochrome P450 3A4 bound to metyrapone and progesterone. Science 305, 683–686 (2004).
Berman, H.M. et al. The protein data bank. Nucleic Acids Res. 28, 235–242 (2000).
Lee, D.S., Nioche, P., Hamberg, M. & Raman, C.S. Structural insights into the evolutionary paths of oxylipin biosynthetic enzymes. Nature 455, 363–368 (2008).
Li, L., Chang, Z., Pan, Z., Fu, Z.Q. & Wang, X. Modes of heme binding and substrate access for cytochrome P450 CYP74A revealed by crystal structures of allene oxide synthase. Proc. Natl. Acad. Sci. USA 105, 13883–13888 (2008).
Ye, Y.Z. & Godzik, A. Flexible structure alignment by chaining aligned fragment pairs allowing twists. Bioinformatics 19, ii246–ii255 (2003).
Kraulis, P.J. Molscript—a program to produce both detailed and schematic plots of protein structures. J. Appl. Cryst. 24, 946–950 (1991).
Merritt, E.A. & Murphy, M.E.P. Raster3d Version-2.0—a program for photorealistic molecular graphics. Acta Crystallogr. D Biol. Crystallogr. 50, 869–873 (1994).
Bolton, E., Wang, Y., Thiessen, P.A. & Bryant, S.H. PubChem: integrated platform of small molecules and biological activities. Annu. Rep. Comput. Chem. 4, 217–241 (2008).
Schuttelkopf, A.W. & van Aalten, D.M. PRODRG: a tool for high-throughput crystallography of protein-ligand complexes. Acta Crystallogr. D Biol. Crystallogr. 60, 1355–1363 (2004).
Morris, G.M. et al. AutoDock4 and AutoDockTools4: automated docking with selective receptor flexibility. J. Comput. Chem. 30, 2785–2791 (2009).
Trott, O. & Olson, A.J. AutoDock Vina: improving the speed and accuracy of docking with a new scoring function, efficient optimization, and multithreading. J. Comput. Chem. 31, 455–461 (2010).
We thank Y. Wang from the Institute of Genetics and Developmental Biology at the Chinese Academy of Science for the p35s:OsD27:PJTK13 plasmid and K. Yoneyama (Weed Science Center, Utsunomiya University, Utsunomiya, Japan) and T. Asami (Department of Applied Biological Chemistry, The University of Tokyo, Japan) for supplying SL standards. We thank J. Beekwilder and K. Cankar (Plant Research International, Wageningen, the Netherlands) for technical advice on the yeast assays and B. Ramakers (Nijmegen University) for technical support with the CD spectra measurement of CL. We thank A. Reeder from the Centre for Microscopy, Characterisation and Analysis (University of Western Australia (UWA)) and M. Clarke from the Centre for Metabolomics (UWA) for technical assistance and instrument access. We acknowledge funding by the Netherlands Organization for Scientific Research (VICI grant 865.06.002 and equipment grant 834.08.001 to H.J.B.), the Australian Research Council (LP0882775 for A.S. and FT110100304 for G.R.F.) and the UK Biotechnology and Biological Sciences Research Council (for J.H. and O.L.). Research reported in this publication was supported by the King Abdullah University of Science and Technology and was cofinanced by the Centre for BioSystems Genomics, which is part of the Netherlands Genomics Initiative/Netherlands Organization for Scientific Research.
The authors declare no competing financial interests.
About this article
Cite this article
Zhang, Y., van Dijk, A., Scaffidi, A. et al. Rice cytochrome P450 MAX1 homologs catalyze distinct steps in strigolactone biosynthesis. Nat Chem Biol 10, 1028–1033 (2014). https://doi.org/10.1038/nchembio.1660
This article is cited by
Fertilization controls tiller numbers via transcriptional regulation of a MAX1-like gene in rice cultivation
Nature Communications (2023)
Strigolactones Stimulate High Light Stress Adaptation by Modulating Photosynthesis Rate in Arabidopsis
Journal of Plant Growth Regulation (2023)
Phytochemistry Reviews (2023)
Journal of Plant Growth Regulation (2023)
Nature Communications (2022)