Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Farnesylation mediates brassinosteroid biosynthesis to regulate abscisic acid responses

Nature Plants volume 2, Article number: 16114 (2016) Cite this article

Subjects

Abstract

Protein farnesylation is a post-translational modification involving the addition of a 15-carbon farnesyl isoprenoid to the carboxy terminus of select proteins1–3. Although the roles of this lipid modification are clear in both fungal and animal signalling, many of the mechanistic functions of farnesylation in plant signalling are still unknown. Here, we show that CYP85A2, the cytochrome P450 enzyme that performs the last step in brassinosteroid biosynthesis (conversion of castasterone to brassinolide)4, must be farnesylated to function in Arabidopsis. Loss of either CYP85A2 or CYP85A2 farnesylation results in reduced brassinolide accumulation and increased plant responsiveness to the hormone abscisic acid (ABA) and overall drought tolerance, explaining previous observations5. This result not only directly links farnesylation to brassinosteroid biosynthesis but also suggests new strategies to maintain crop yield under challenging climatic conditions.

The At3g30180 gene encodes a cytochrome P450 (CYP85A2) that exclusively mediates the conversion of castasterone to brassinolide in the rate-limiting final step during synthesis of the plant steroid hormones, the brassinosteroids4. The lack of brassinosteroid-deficient phenotypes such as severe dwarfism in our CYP85A2 insertion allele (cyp85a2-2) was at first surprising. However, previous characterization of CYP85A2 knockout lines show that these mutants exhibit weak brassinosteroid-dependent phenotypes because of a redundant activity due to a related cytochrome p450 enzyme, CYP85A1, that can lead to accumulation of bioactive castasterone4. However, this enzyme is unable to substitute for CYP85A2 in the conversion of castasterone to brassinolide4. Consistent with this, we found cyp85a2-2 to have slightly increased DWF4 expression and slightly reduced SAUR-AC expression, which are common expression signatures of reduced brassinosteroid levels (Supplementary Fig. 1B)6. Interestingly, CYP85A1 does not contain a canonical CaaX box and therefore its function should not be influenced by farnesylation.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it

$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

Figure 1: cyp85a2-2 and era1-2 mutants have overlapping phenotypes.
Figure 2: Lack of ERA1 results in reduced brassinolide accumulation.
Figure 3: Farnesylation is required for CYP85A2 function.
Figure 4: Farnesylation of CYP85A2 is required for ER localization.

References

  1. Andrews, M., Huizinga, D. H. & Crowell, D. N. The CaaX specificities of Arabidopsis protein prenyltransferases explain era1 and ggb phenotypes. BMC Plant Biol. 10, 118 (2010).

    Article  Google Scholar 

  2. Reiss, Y., Stradley, S. J., Gierasch, L. M., Brown, M. S. & Goldstein, J. L. Sequence requirement for peptide recognition by rat brain p21ras protein farnesyltransferase. Proc. Natl Acad. Sci. USA 88, 732–736 (1991).

    Article  CAS  Google Scholar 

  3. Running, M. P. The role of lipid post-translational modification in plant developmental processes. Front. Plant Sci. 5, 50 (2014).

    Article  Google Scholar 

  4. Kim, T.-W. et al. Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis. Plant Cell 17, 2397–2412 (2005).

    Article  CAS  Google Scholar 

  5. Cutler, S., Ghassemian, M., Bonetta, D., Cooney, S. & McCourt, P. A protein farnesyl transferase involved in abscisic acid signal transduction in Arabidopsis. Science 273, 1239–1241 (1996).

    Article  CAS  Google Scholar 

  6. Tang, W. et al. BSKs mediate signal transduction from the receptor kinase BRI1 in Arabidopsis. Science 321, 557–560 (2008).

    Article  CAS  Google Scholar 

  7. Ryu, H., Cho, H., Bae, W. & Hwang, I. Control of early seedling development by BES1/TPL/HDA19-mediated epigenetic regulation of ABI3. Nature Commun. 5, 4138 (2014).

    Article  CAS  Google Scholar 

  8. Cai, Z. et al. GSK3-like kinases positively modulate abscisic acid signaling through phosphorylating subgroup III SnRK2s in Arabidopsis. Proc. Natl Acad. Sci. USA 111, 9651–9656 (2014).

    Article  CAS  Google Scholar 

  9. Steber, C. M. & McCourt, P. A role for brassinosteroids in germination in Arabidopsis. Plant Physiol. 125, 763–769 (2001).

    Article  CAS  Google Scholar 

  10. Park, J. W., Reed, J. R., Brignac-Huber, L. M. & Backes, W. L. Cytochrome P450 system proteins reside in different regions of the endoplasmic reticulum. Biochem. J. 464, 241–249 (2014).

    Article  CAS  Google Scholar 

  11. Zhang, F. L. & Casey, P. J. Protein prenylation: molecular mechanisms and functional consequences. Annu. Rev. Biochem. 65, 241–269 (1996).

    Article  CAS  Google Scholar 

  12. Hancock, J. F., Cadwallader, K., Paterson, H. & Marshall, C. J. A CAAX or a CAAL motif and a second signal are sufficient for plasma membrane targeting of ras proteins. EMBO J. 10, 4033 (1991).

    Article  CAS  Google Scholar 

  13. Pfeffer, S. & Aivazian, D. Targeting Rab GTPases to distinct membrane compartments. Nature Rev. Mol. Cell Biol. 5, 886–896 (2004).

    Article  CAS  Google Scholar 

  14. Kozuka, T. et al. Involvement of auxin and brassinosteroid in the regulation of petiole elongation under the shade. Plant Physiol. 153, 1608–1618 (2010).

    Article  CAS  Google Scholar 

  15. Andersson, M. X., Goksör, M. & Sandelius, A. S. Optical manipulation reveals strong attracting forces at membrane contact sites between endoplasmic reticulum and chloroplasts. J. Biol. Chem. 282, 1170–1174 (2007).

    Article  CAS  Google Scholar 

  16. Kagale, S., Divi, U. K., Krochko, J. E., Keller, W. A. & Krishna, P. Brassinosteroid confers tolerance in Arabidopsis thaliana and Brassica napus to a range of abiotic stresses. Planta 225, 353–364 (2007).

    Article  CAS  Google Scholar 

  17. Bajguz, A. & Hayat, S. Effects of brassinosteroids on the plant responses to environmental stresses. Plant Physiol. Biochem. 47, 1–8 (2009).

    Article  CAS  Google Scholar 

  18. Yuan, G.-F. et al. Effect of brassinosteroids on drought resistance and abscisic acid concentration in tomato under water stress. Sci. Horticult. 126, 103–108 (2010).

    Article  CAS  Google Scholar 

  19. Anjum, S. A. et al. Brassinolide application improves the drought tolerance in maize through modulation of enzymatic antioxidants and leaf gas exchange. J. Agron. Crop Sci. 197, 177–185 (2011).

    Article  CAS  Google Scholar 

  20. Zhou, J. et al. H2O2 mediates the crosstalk of brassinosteroid and abscisic acid in tomato responses to heat and oxidative stresses. J. Exp. Bot. 65, 4371–4383 (2014).

    Article  CAS  Google Scholar 

  21. Rodrigues, A. et al. The short-rooted phenotype of the Brevis radix mutant partly reflects root abscisic acid hypersensitivity. Plant Physiol. 149, 1917–1928 (2009).

    Article  CAS  Google Scholar 

  22. Li, Z.-Y. et al. A mutation in Arabidopsis BSK5 encoding a brassinosteroid-signaling kinase protein affects responses to salinity and abscisic acid. Biochem. Biophys. Res. Commun. 426, 522–527 (2012).

    Article  CAS  Google Scholar 

  23. Hu, Y. & Yu, D. BRASSINOSTEROID INSENSITIVE2 interacts with ABSCISIC ACID INSENSITIVE5 to mediate the antagonism of brassinosteroids to abscisic acid during seed germination in Arabidopsis. Plant Cell 26, 4394–4408 (2014).

    Article  CAS  Google Scholar 

  24. Nomura, T. et al. The last reaction producing brassinolide is catalyzed by cytochrome P-450s, CYP85A3 in tomato and CYP85A2 in Arabidopsis. J. Bio. Chem. 280, 17873–17879 (2005).

    Article  CAS  Google Scholar 

  25. Clough, S. J. & Bent, A. F. Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 16, 735–743 (2008).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by Natural Sciences and Engineering Research Council of Canada funding for P.M. and M.A.S. We thank S. Urquhart (University of Tasmania) for assistance with hormone extraction and D. Nichols and N. Davies (University of Tasmania) for assistance with hormone quantification. We thank D. K. Ro (University of Calgary) for helpful discussions on cytochrome p450 enzymes and their functions.

Author information

Author notes

  1. Julian G. B. Northey and Siyu Liang: These authors contributed equally to this work.

Authors and Affiliations

  1. Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Ontario, Canada

    Julian G. B. Northey & Peter McCourt

  2. Department of Biological Sciences, University of Calgary, BI 392, 2500 University Drive NW, Calgary, T2N 1N4, Alberta, Canada

    Siyu Liang, Muhammad Jamshed, Srijani Deb & Marcus A. Samuel

  3. School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, 7001, Tasmania, Australia

    Eloise Foo & James B. Reid

Authors
  1. Julian G. B. Northey
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Siyu Liang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Muhammad Jamshed
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Srijani Deb
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Eloise Foo
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. James B. Reid
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Peter McCourt
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Marcus A. Samuel
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

J.N., P.M. and M.A.S. initiated the project. J.N., S.L., P.M. and M.A.S. designed the research; J.N., S.L., M.J., S.D. and M.A.S. performed all the experiments; E.F. and J.B.R. undertook brassinosteroid quantifications and analysis; J.N., S.L. and M.A.S. analysed data; and P.M. and M.A.S. wrote the manuscript. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Peter McCourt or Marcus A. Samuel.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Methods, Supplementary References, Supplementary Tables 1-3 and Supplementary Figs 1-7. (PDF 1950 kb)

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Northey, J., Liang, S., Jamshed, M. et al. Farnesylation mediates brassinosteroid biosynthesis to regulate abscisic acid responses. Nature Plants 2, 16114 (2016). https://doi.org/10.1038/nplants.2016.114

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1038/nplants.2016.114

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing