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A channel-like transporter for NH4+ on the symbiotic interface of N2-fixing plants

Abstract

SYMBIOSIS with nitrogen-fixing bacteria (rhizobia) allows legumes to survive in nitrogen-poor soils. The nitrogen-fixing bacteroids are found inside root nodule cells within the symbiosome, an organelle bounded by the peribacteroid membrane1. Across this membrane the plant receives fixed nitrogen in exchange for reduced carbon2. It has been assumed that fixed nitrogen is released from the symbiosome as either NH3 or NH4+ , but until now the transport mechanism was unknown3–5. We report here the use of patch-clamp techniques to show, in membrane patches on isolated symbiosomes, smoothly activating currents that are passive and equivalent to the influx of cations to the plant cytoplasm. The currents are largest with NH4+ as the cation at physiological concentration and they are blocked by calcium ions on the bacteroid side of the membrane. The characteristics of the currents are more like those of a channel than of carrier-mediated transport. In vivo nitrogen would move passively as NH4+ to the cytoplasm upon energization of the membrane and calcium ions may be involved in regulation of the flux.

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References

  1. Day, D. A. & Udvardi, M. K. Symbiosis 14, 175–189 (1992).

    Google Scholar 

  2. Udvardi, M. K., Price, G. D., Gresshoff, P. M. & Day, D. A. FEBS Lett. 231, 36–40 (1988).

    Article  CAS  Google Scholar 

  3. Blumwald, E., Fortin, M. G., Rea, P. A., Verma, D. P. S. & Poole, R. J. Pl. Physiol. 78, 665–672 (1985).

    Article  CAS  Google Scholar 

  4. Shearer, G. & Kohl, D. H. Aust. J. Pl. Physiol. 16, 305–313 (1989).

    CAS  Google Scholar 

  5. Udvardi, M. K. & Day, D. A. Pl. Physiol. 94, 71–76 (1990).

    Article  CAS  Google Scholar 

  6. Day, D. A., Price, G. D. & Udvardi, M. K. Aust. J. Pl. Physiol. 16, 69–84 (1989).

    CAS  Google Scholar 

  7. Streeter, J. G. Pl. Physiol. 90, 779–782 (1989).

    Article  CAS  Google Scholar 

  8. Vincent, J. M. & Humphrey, B. A. Nature 199, 149–151 (1963).

    Article  ADS  CAS  Google Scholar 

  9. Nekolla, S., Anderson, C. & Benz, R. Biophys. J. 66, 1388–1397 (1994).

    Article  CAS  Google Scholar 

  10. McGeoch, M. W. & McGeoch, J. E. M. Biophys. J. 66, 161–168 (1994).

    Article  ADS  CAS  Google Scholar 

  11. Sauvé, R. & Szabo, G. J. theor. Biol. 113, 501–516 (1985).

    Article  Google Scholar 

  12. Kolb, H.-A. & Läuger, P. J. Membr. Biol. 41, 167–187 (1978).

    Article  Google Scholar 

  13. Sigworth, F. J. J. Physiol. 307, 97–129 (1980).

    Article  CAS  Google Scholar 

  14. Heinemann, S. H. & Conti, F. Meth. Enzym. 207, 131–148 (1992).

    Article  CAS  Google Scholar 

  15. Silberberg, S. D. & Magleby, K. L. Biophys. J. 65, 1570–1584 (1993).

    Article  CAS  Google Scholar 

  16. Hainsworth, A. H., Levis, R. A. & Eisenberg, R. S. J. gen. Physiol. 104, 857–883 (1994).

    Article  CAS  Google Scholar 

  17. Bergersen, F. J. Protoplasma 183, 49–61 (1994).

    Article  Google Scholar 

  18. Brewin, N. J. et al. EMBO J. 4, 605–611 (1985).

    Article  CAS  Google Scholar 

  19. Frommer, W. B. et al. Pl. molec. Biol. 26, 1651–1670 (1994).

    Article  CAS  Google Scholar 

  20. Bodoia, R. D. & Detwiler, P. B. J. Physiol. 367, 183–216 (1984).

    Article  Google Scholar 

  21. Fesenko, E. E., Kolesnikov, S. S. & Lyubarsky, A. L. Nature 313, 310–313 (1985).

    Article  ADS  CAS  Google Scholar 

  22. Tyerman, S. D. A. Rev. Pl. Physiol. Pl. molec. Biol. 43, 351–373 (1992).

    Article  CAS  Google Scholar 

  23. Hedrich, R. & Becker, D. Pl. molec. Biology 26, 1637–1650 (1994).

    Article  CAS  Google Scholar 

  24. Schroeder, J. I., Ward, J. M. & Gassmann, W. A. Rev. Biophys. biomolec. Struct. 23, 441–471 (1994).

    Article  CAS  Google Scholar 

  25. Marini, A.-M., Vissers, S., Urrestarazu, A. & André, B. EMBO J. 13, 3456–3463 (1994).

    Article  CAS  Google Scholar 

  26. Ninnemann, O. W., Jauniauex, J. C. & Frommer, W. B. EMBO J. 13, 3464–3471 (1994).

    Article  CAS  Google Scholar 

  27. Schachtman, D. P., Tyerman, S. D. & Terry, B. R. Pl. Physiol. 97, 598–605 (1991).

    Article  CAS  Google Scholar 

  28. Barry, P. H. & Lynch, J. W. J. Membr. Biol. 121, 101–117 (1991).

    Article  CAS  Google Scholar 

  29. Skerrett, M. & Tyerman, S. D. Planta 192, 295–305 (1994).

    Article  CAS  Google Scholar 

  30. Sakmann, B. & Neher, E. in Single Channel Recording (eds Sakmann, B. & Neher, E.) 37–51 (Plenum, New York, 1983).

    Book  Google Scholar 

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Tyerman, S., Whitehead, L. & Day, D. A channel-like transporter for NH4+ on the symbiotic interface of N2-fixing plants. Nature 378, 629–632 (1995). https://doi.org/10.1038/378629a0

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