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.

  • Article
  • Published:

Engineering a K+ channel ‘sensory antenna’ enhances stomatal kinetics, water use efficiency and photosynthesis

Abstract

Stomata of plant leaves open to enable CO2 entry for photosynthesis and close to reduce water loss via transpiration. Compared with photosynthesis, stomata respond slowly to fluctuating light, reducing assimilation and water use efficiency. Efficiency gains are possible without a cost to photosynthesis if stomatal kinetics can be accelerated. Here we show that clustering of the GORK channel, which mediates K+ efflux for stomatal closure in the model plant Arabidopsis, arises from binding between the channel voltage sensors, creating an extended ‘sensory antenna’ for channel gating. Mutants altered in clustering affect channel gating to facilitate K+ flux, accelerate stomatal movements and reduce water use without a loss in biomass. Our findings identify the mechanism coupling channel clustering with gating, and they demonstrate the potential for engineering of ion channels native to the guard cell to enhance stomatal kinetics and improve water use efficiency without a cost in carbon fixation.

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

Access options

Buy this article

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

Fig. 1: GORK K+ channels interact through the cytosolic N-termini of the voltage sensor domains.
Fig. 2: Alternation of charges defines GORK–VSD interactions.
Fig. 3: Non-interacting channel mutations suppress GORK clustering when stably expressed in Arabidopsis.
Fig. 4: Non-interacting GORK channel mutations express functional K+ channels with displaced midpoint voltages.
Fig. 5: Non-interacting GORK channel mutations accelerate stomatal closure and enhance WUE.
Fig. 6: A mechanism coupling GORK clustering and gating through a binding exchange of the VSD N-terminus.

Similar content being viewed by others

Data availability

Data generated and analysed during this study are included in the article, its supplementary information files, and are also available on reasonable request to the corresponding author. Source data are provided with this paper.

Code availability

The OnGuard3 platform and the model parameter sets are freely available to academic users and may be downloaded from www.psrg.org.uk.

References

  1. Hetherington, A. M. & Woodward, F. I. The role of stomata in sensing and driving environmental change. Nature 424, 901–908 (2003).

    Article  CAS  PubMed  Google Scholar 

  2. Lawson, T. & Blatt, M. R. Stomatal size, speed, and responsiveness impact on photosynthesis and water use efficiency. Plant Physiol. 164, 1556–1570 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Beljaars, A. C. M., Viterbo, P., Miller, M. J. & Betts, A. K. The anomalous rainfall over the United States during July 1993: sensitivity to land surface parameterization and soil moisture. Mon. Weather Rev. 124, 362–383 (1996).

    Article  Google Scholar 

  4. Berry, J. A., Beerling, D. J. & Franks, P. J. Stomata: key players in the Earth system, past and present. Curr. Opin. Plant Biol. 13, 233–240 (2010).

    Article  PubMed  Google Scholar 

  5. Water for a Sustainable WorldUN World Water Development Report. Vol. 1 (UNESCO, 2015).

  6. Jezek, M. & Blatt, M. R. The membrane transport system of the guard cell and its integration for stomatal dynamics. Plant Physiol. 174, 487–519 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Assmann, S. M. & Jegla, T. Guard cell sensory systems: recent insights on stomatal responses to light, abscisic acid, and CO2. Curr. Opin. Plant Biol. 33, 157–167 (2016).

    Article  CAS  PubMed  Google Scholar 

  8. Nakamura, R. L. et al. Expression of an Arabidopsis potassium channel gene in guard cells. Plant Physiol. 109, 371–374 (1995).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Pilot, G., Gaymard, F., Mouline, K., Cherel, I. & Sentenac, H. Regulated expression of Arabidopsis Shaker K+ channel genes involved in K+ uptake and distribution in the plant. Plant Mol. Biol. 51, 773–787 (2003).

    Article  CAS  PubMed  Google Scholar 

  10. Lebaudy, A. et al. Plant adaptation to fluctuating environment and biomass production are strongly dependent on guard cell potassium channels. Proc. Natl Acad. Sci. USA 105, 5271–5276 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Pilot, G. et al. Guard cell inward K+ channel activity in Arabidopsis involves expression of the twin channel subunits KAT1 and KAT2. J. Biol. Chem. 276, 3215–3221 (2001).

    Article  CAS  PubMed  Google Scholar 

  12. Clint, G. M. & Blatt, M. R. Mechanisms of fusicoccin action: evidence for concerted modulations of secondary K+ transport in a higher-plant cell. Planta 178, 495–508 (1989).

    Article  CAS  PubMed  Google Scholar 

  13. Blatt, M. R. & Clint, G. M. Mechanisms of fusicoccin action kinetic modification and inactivation of potassium channels in guard cells. Planta 178, 509–523 (1989).

    Article  CAS  PubMed  Google Scholar 

  14. Maathuis, F. J. M. & Sanders, D. Mechanism of high-affinity potassium uptake in roots of Arabidopsis thaliana. Proc. Natl Acad. Sci. USA 91, 9272–9276 (1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Very, A.-A. et al. Molecular biology of K+ transport across the plant cell membrane: what do we learn from comparison between plant species? J. Plant Physiol. 171, 748–769 (2014).

    Article  CAS  PubMed  Google Scholar 

  16. Hosy, E. et al. The Arabidopsis outward K+ channel GORK is involved in regulation of stomatal movements and plant transpiration. Proc. Natl Acad. Sci. USA 100, 5549–5554 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Ache, P. et al. GORK, a delayed outward rectifier expressed in guard cells of Arabidopsis thaliana, is a K+-selective, K+-sensing ion channel. FEBS Lett. 486, 93–98 (2000).

    Article  CAS  PubMed  Google Scholar 

  18. Blatt, M. R. Potassium-dependent bipolar gating of potassium channels in guard cells. J. Membr. Biol. 102, 235–246 (1988).

    Article  Google Scholar 

  19. Blatt, M. R. & Gradmann, D. K+-sensitive gating of the K+ outward rectifier in Vicia guard cells. J. Membr. Biol. 158, 241–256 (1997).

    Article  CAS  PubMed  Google Scholar 

  20. Eisenach, C., Papanatsiou, M., Hillert, E. K. & Blatt, M. R. Clustering of the K+ channel GORK of Arabidopsis parallels its gating by extracellular K+. Plant J. 78, 203–214 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Gaymard, F. et al. Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap. Cell 94, 647–655 (1998).

    Article  CAS  PubMed  Google Scholar 

  22. Johansson, I. et al. External K+ modulates the activity of the Arabidopsis potassium channel SKOR via an unusual mechanism. Plant J. 46, 269–281 (2006).

    Article  CAS  PubMed  Google Scholar 

  23. Riedelsberger, J. et al. Distributed structures underlie gating differences between the Kin channel KAT1 and the Kout channel SKOR. Mol. Plant 3, 236–245 (2010).

    Article  CAS  PubMed  Google Scholar 

  24. Gajdanowicz, P. et al. Distributed structures determine K+ and voltage dependent gating of the Kin channel KAT1 and the Kout channel SKOR. N. Phytol. 182, 380–391 (2009).

    Article  CAS  Google Scholar 

  25. Jegla, T., Busey, G. & Assmann, S. M. Evolution and structural characteristics of plant voltage-gated K+ channels. Plant Cell 30, 2898–2909 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Pozdnyakov, I., Safonov, P. & Skarlato, S. Diversity of voltage-gated potassium channels and cyclic nucleotide-binding domain-containing channels in eukaryotes. Sci. Rep. 10, 13 (2020).

    Article  Google Scholar 

  27. Dreyer, I. & Blatt, M. R. What makes a gate? The ins and outs of Kv-like K+ channels in plants. Trends Plant Sci. 14, 383–390 (2009).

    Article  CAS  PubMed  Google Scholar 

  28. Very, A. A. & Sentenac, H. Cation channels in the Arabidopsis plasma membrane. Trends Plant Sci. 7, 168–175 (2002).

    Article  CAS  PubMed  Google Scholar 

  29. Yellen, G. The voltage-gated potassium channels and their relatives. Nature 419, 35–42 (2002).

    Article  CAS  PubMed  Google Scholar 

  30. Palovcak, E., Delemotte, L., Klein, M. L. & Carnevale, V. Evolutionary imprint of activation: the design principles of VSDs. J. Gen. Physiol. 143, 145–156 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Lefoulon, C. The bare necessities of plant K+ channel regulation. Plant Physiol. 187, 2092–2109 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Lefoulon, C. et al. Voltage-sensor transitions of the inward-rectifying K+ channel KAT1 indicate a closed-to-open latching mechanism that is biased by hydration around the S4 α-helix. Plant Physiol. 166, 960–975 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  33. Grefen, C. et al. A vesicle-trafficking protein commandeers Kv channel voltage sensors for voltage-dependent secretion. Nat. Plants 1, 15108–15119 (2015).

    Article  CAS  PubMed  Google Scholar 

  34. Honsbein, A. et al. A tripartite SNARE-K+ channel complex mediates in channel-dependent K+ nutrition in Arabidopsis. Plant Cell 21, 2859–2877 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Grefen, C., Obrdlik, P. & Harter, K. The determination of protein–protein interactions byt the mating-based split-ubiquitin system (mbSUS). Methods Mol. Biol. 479, 1–17 (2009).

    Google Scholar 

  36. Grefen, C. & Blatt, M. R. A 2in1 cloning system enables ratiometric bimolecular fluorescence complementation (rBiFC). Biotechniques 53, 311–314 (2012).

    Article  CAS  PubMed  Google Scholar 

  37. Fricker, M. D., Runions, J. & Moore, I. Quantitative fluorescence microscopy: from art to science. Ann. Rev. Plant Biol. 57, 79–107 (2006).

    Article  CAS  Google Scholar 

  38. Gould, G. W. Membrane Protein Expression Systems. Vol. 1 (Portland Press, 1994).

  39. Lefoulon, C., Waghmare, S., Karnik, R. & Blatt, M. R. Gating control and K+ uptake by the KAT1 K+ channel leaveraged through membrane anchoring of the trafficking protein SYP121. Plant Cell Environ. 41, 2668–2677 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Grefen, C. et al. A ubiquitin-10 promoter-based vector set for fluorescent protein tagging facilitates temporal stability and native protein distribution in transient and stable expression studies. Plant J. 64, 355–365 (2010).

    Article  CAS  PubMed  Google Scholar 

  41. Yang, Y. Z., Costa, A., Leonhardt, N., Siegel, R. S. & Schroeder, J. I. Isolation of a strong Arabidopsis guard cell promoter and its potential as a research tool. Plant Methods 4, 4–6 (2008).

    Article  Google Scholar 

  42. Wang, Y. et al. Unexpected connections between humidity and ion transport discovered using a model to bridge guard cell-to-leaf scales. Plant Cell 29, 2921–2139 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Wang, Y. et al. Systems dynamic modelling of a guard cell Cl channel mutant uncovers an emergent homeostatic network regulating stomatal transpiration. Plant Physiol. 160, 1956–1972 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Eisenach, C., Chen, Z. H., Grefen, C. & Blatt, M. R. The trafficking protein SYP121 of Arabidopsis connects programmed stomatal closure and K+ channel acivity with vegetative growth. Plant J. 69, 241–251 (2012).

    Article  CAS  PubMed  Google Scholar 

  45. Blatt, M. R. K+ channels of stomatal guard cells: characteristics of the inward rectifier and its control by pH. J. Gen. Physiol. 99, 615–644 (1992).

    Article  CAS  PubMed  Google Scholar 

  46. Jezek, M. et al. Guard cell endomembrane Ca2+-ATPases underpin a ‘carbon memory’ of photosynthetic assimilation that impacts on water use efficiency. Nat. Plants 7, 1301–1307 (2021).

    Article  CAS  PubMed  Google Scholar 

  47. Becker, D. et al. Regulation of the ABA-sensitive Arabidopsis potassium channel gene GORK in response to water stress. FEBS Lett. 554, 119–126 (2003).

    Article  CAS  PubMed  Google Scholar 

  48. Papanatsiou, M. et al. Optogenetic manipulation of stomatal kinetics improves carbon assimilation and water use efficiency. Science 363, 1456–1459 (2019).

    Article  CAS  PubMed  Google Scholar 

  49. Sharkey, T. D., Bernacchi, C. J., Farquhar, G. D. & Singsaas, E. L. Fitting photosynthetic carbon dioxide response curves for C-3 leaves. Plant Cell Environ. 30, 1035–1040 (2007).

    Article  CAS  PubMed  Google Scholar 

  50. Tester, M. Plant ion channels: whole-cell and single-channel studies. N. Phytol. 114, 305–340 (1990).

    Article  Google Scholar 

  51. Lai, H. C. & Jan, L. Y. The distribution and targeting of neuronal voltage-gated ion channels. Nat. Rev. Neurosci. 7, 548–562 (2006).

    Article  CAS  PubMed  Google Scholar 

  52. Deutsch, E. et al. Kv2.1 cell surface clusters are insertion platforms for ion channel delivery to the plasma membrane. Mol. Biol. Cell 23, 2917–2929 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Tamkun, M. M., O’Connell, K. M. S. & Rolig, A. S. A cytoskeletal-based perimeter fence selectively corrals a sub-population of cell surface Kv2.1 channels. J. Cell Sci. 120, 2413–2423 (2007).

    Article  CAS  PubMed  Google Scholar 

  54. Sutter, J. U., Campanoni, P., Tyrrell, M. & Blatt, M. R. Selective mobility and sensitivity to SNAREs is exhibited by the Arabidopsis KAT1 K+ channel at the plasma membrane. Plant Cell 18, 935–954 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Sutter, J. U. et al. Abscisic acid triggers the endocytosis of the Arabidopsis KAT1 K+ channel and its recycling to the plasma membrane. Curr. Biol. 17, 1396–1402 (2007).

    Article  CAS  PubMed  Google Scholar 

  56. Karnik, R. et al. Commandeering channel voltage sensors for secretion, cell turgor, and volume control. Trends Plant Sci. 11, 81–95 (2017).

    Article  Google Scholar 

  57. Thiel, G., MacRobbie, E. A. C. & Blatt, M. R. Membrane transport in stomatal guard cells: the importance of voltage control. J. Membr. Biol. 126, 1–18 (1992).

    Article  CAS  PubMed  Google Scholar 

  58. Blatt, M. R. Potassium channel currents in intact stomatal guard cells: rapid enhancement by abscisic acid. Planta 180, 445–455 (1990).

    Article  CAS  PubMed  Google Scholar 

  59. Horaruang, W. The Mechanism of GORK K+ Channel Gating and Clustering. PhD thesis, Univ. Glasgow (2019).

  60. Dickinson, M. S., Pourmal, S., Gupta, M., Bi, M. & Stroud, R. M. Symmetry reduction in a hyperpolarization-activated homotetrameric ion channel. Biochemistry in press, https://doi.org/10.1021/acs.biochem.1c00654 (2022).

  61. Lee, C.-H. & MacKinnon, R. Structures of the human HCN1 hyperpolarization-activated channel. Cell 168, 111 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Porro, A. et al. The HCN domain couples voltage gating and cAMP response in hyperpolarization-activated cyclic nucleotide-gated channels. eLife 8, e49672 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  63. Doheny-Adams, T., Hunt, L., Franks, P. J., Beerling, D. J. & Gray, J. E. Genetic manipulation of stomatal density influences stomatal size, plant growth and tolerance to restricted water supply across a growth carbon dioxide gradient. Philos. Trans. R. Soc. B 367, 547–555 (2012).

    Article  CAS  Google Scholar 

  64. Masle, J., Gilmore, S. R. & Farquhar, G. D. The ERECTA gene regulates plant transpiration efficiency in Arabidopsis. Nature 436, 866–870 (2005).

    Article  CAS  PubMed  Google Scholar 

  65. Wang, Y., Hills, A. & Blatt, M. R. Systems analysis of guard cell membrane transport for enhanced stomatal dynamics and water use efficiency. Plant Physiol. 164, 1593–1599 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Kusumi, K., Hirotsuka, S., Kumamaru, T. & Iba, K. Increased leaf photosynthesis caused by elevated stomatal conductance in a rice mutant deficient in SLAC1, a guard cell anion channel protein. J. Exp. Bot. 63, 5635–5644 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. Wang, Y. et al. Overexpression of plasma membrane H+-ATPase in guard cells promotes light-induced stomatal opening and enhances plant growth. Proc. Natl Acad. Sci. USA 111, 533–538 (2014).

    Article  CAS  PubMed  Google Scholar 

  68. Hecker, A. et al. Binary 2in1 vectors improve in planta (co-)localisation and dynamic protein interaction studies. Plant Physiol. 168, 776–787 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  69. Grefen, C. et al. A novel motif essential for SNARE interaction with the K+ channel KC1 and channel gating in Arabidopsis. Plant Cell 22, 3076–3092 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. Waghmare, S. et al. K+ channel–SEC11 binding exchange regulates SNARE assembly for secretory traffic. Plant Physiol. 181, 1096–1113 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  71. Tyrrell, M. et al. Selective targeting of plasma membrane and tonoplast traffic by inhibitory (dominant-negative) SNARE fragments. Plant J. 51, 1099–1115 (2007).

    Article  CAS  PubMed  Google Scholar 

  72. Sani, E., Herzyk, P., Perrella, G., Colot, V. & Amtmann, A. Hyperosmotic priming of Arabidopsis seedlings establishes a long-term somatic memory accompanied by specific changes of the epigenome. Genome Biol. 14, R59 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  73. Rasband, W. S. & Bright, D. S. NIH IMAGE—a public domain image-processing program for the Macintosh. Microbeam Anal. 4, 137–149 (1995).

    CAS  Google Scholar 

  74. Chen, Z. H., Hills, A., Lim, C. K. & Blatt, M. R. Dynamic regulation of guard cell anion channels by cytosolic free Ca2+ concentration and protein phosphorylation. Plant J. 61, 816–825 (2010).

    Article  CAS  PubMed  Google Scholar 

  75. Blatt, M. R. Electrical characteristics of stomatal guard cells: the contribution of ATP-dependent, ‘electrogenic’ transport revealed by current-voltage and difference-current-voltage analysis. J. Membr. Biol. 98, 257–274 (1987).

    Article  CAS  Google Scholar 

  76. Hills, A., Chen, Z. H., Amtmann, A., Blatt, M. R. & Lew, V. L. OnGuard, a computational platform for quantitative kinetic modeling of guard cell physiology. Plant Physiol. 159, 1026–1042 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Chen, Z. H. et al. Systems dynamic modeling of the stomatal guard cell predicts emergent behaviors in transport, signaling, and volume control. Plant Physiol. 159, 1235–1251 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  78. Jezek, M., Hills, A., Blatt, M. R. & Lew, V. L. A constraint–relaxation–recovery mechanism for stomatal dynamics. Plant, Cell Environ. 42, 2399–2410 (2019).

    Article  CAS  Google Scholar 

  79. Karnik, R. et al. Arabidopsis Sec1/Munc18 protein SEC11 is a competitive and dynamic modulator of SNARE binding and SYP121-dependent vesicle traffic. Plant Cell 25, 1368–1382 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

This work was supported by BBSRC grants BB/L001276/1, BB/L019205/1, BB/M001601/1 and BB/ T013508/1 to M.R.B., by a Royal Thai PhD studentship to W.H., a University of Glasgow Doctoral Training Studentship to W.C., a Lord Kelvin-Adam Smith Doctoral Fellowship to F.A.L.S.-A. and BBSRC grant BB/R019894/1 to A.A. We thank N. Donald for support in mbSUS assays and A. Ruiz-Pardo for help in plant maintenance.

Author information

Authors and Affiliations

Authors

Contributions

M.R.B. conceived the work and developed the strategies for analysis with B.Z., J.C.A. and A.H.; W.H., W.C. and B.Z. carried out and analysed the mbSUS assays; W.H. carried out oocyte electrophyiology and, with J.C.A., M.K. and M.R.B., the confocal, gas exchange and growth studies; M.K. carried out the guard cell electrophysiology and analysed the results with M.R.B.; S.W. expressed and purified the channel N-termini and carried out the gel filtration studies; M.P. and A.A. undertook the hydroponic growth studies; M.R.B. carried out the modelling with A.H., J.C.A., W.H., F.A.L.S.-A. and M.K.; M.R.B. wrote the manuscript, and all authors edited and approved the manuscript.

Corresponding author

Correspondence to Michael R. Blatt.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Plants thanks Anna Moroni, Xin-Guang Zhu, Nobuyuki Uozumi and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Tables 1–3, Figs. 1–15 and Appendix 1.

Reporting Summary

Source data

Source Data Fig. 3

Numerical data and statistics for Fig. 3b.

Source Data Fig. 4

Numerical data for Fig. 4a–f.

Source Data Fig. 5

Numerical data for Fig. 5a–c,e,f.

Rights and permissions

Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Horaruang, W., Klejchová, M., Carroll, W. et al. Engineering a K+ channel ‘sensory antenna’ enhances stomatal kinetics, water use efficiency and photosynthesis. Nat. Plants 8, 1262–1274 (2022). https://doi.org/10.1038/s41477-022-01255-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41477-022-01255-2

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