Abstract
The expression pattern of the KDC1gene, coding for an inwardly-rectifying K+ channel of Daucus carota, is described in several embryo stages and seedling tissues. Relative quantitative RT-PCR experiments indicated that, during (somatic) embryonic development, the KDC1 transcript appears as early as the globular stage and that the transcript level remains constant throughout the successive heart and torpedo stages. Thereafter, the KDC1 transcript is preferentially expressed in plant roots, but is also present in other tissues, and in particular, in the shoot apical meristem. In situ hybridisation experiments showed that in embryos KDC1 mRNA is detectable preferentially in protoderm cells with a stage dependent expression pattern. At later times, the hybridisation signal is particularly evident in root hairs, root epidermis and endodermis, but is also observed in single cell layers corresponding to L1 of the shoot apical meristem and leaf primordia. Promoter studies with the β-glucuronidase reporter gene confirm preferential expression of KDC1 in embryo protoderm cells and in plant root epidermis and root hairs. Western blot analysis of embryonic proteins and immunolocalisation experiments on somatic embryos sections revealed the presence of KDC1 during embryo development. Consistent with these observations, patch-clamp experiments performed on protoplasts isolated from embryos at the torpedo stage demonstrated the presence of functional inward rectifying K+ channels. This is the first report on the expression of a plant ion channel during embryo development.
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Ache, P., Becker, D., Ivashikina, N., Dietrich, P., Roelfsema, M.R. and Hedrich, R. 2000. 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.
Amtmann, A., Jelitto, T.C. and Sanders, D. 1999. K+-Selective inward-rectifying channels and apoplastic pH in barley roots. Plant Physiol. 120: 331–338.
Barizza, E., Lo Schiavo, F., Terzi, M. and Filippini, F. 1999. Evidence suggesting protein tyrosine phosphorylation in plants depends on the developmental conditions. FEBS Lett. 447: 191–194.
Brownlee, C. 2002. Plant K+transport: Not just an uphill struggle. Curr. Biol. 12: 402–404.
Brüggemann, L., Dietrich, P., Dreyer, I. and Hedrich, R. 1999. Pronounced differences between the native K+ channels and KAT1 and KST1 alpha-subunit homomers of guard cells. Planta 207: 370–376.
Clarkson, D.T. and Hanson, J.B. 1980. The mineral nutrition of higher plants. Annu. Rev. Plant Physiol. 31: 239–298.
Deeken, R., Sanders, C., Ache, P. and Hedrich, R. 2000. Developmental and light-dependent regulation of a phloemlocalised K+ channel of Arabidopsis thaliana. Plant J. 23: 285–290.
Desbrosses, G., Josefsson, C., Rigas, S., Hatzopoulos, P. and Dolan, L. 2003. AKT1 and TRH1 are required during root hair elongation in Arabidopsis. J. Exp. Bot. 54: 781–788.
Does, M.P., Dekker, B.M., de Groot, M.J. and Offringa, R. 1991. A quick method to estimate the T-DNA copy number in transgenic plants at an early stage after transformation, using inverse PCR. Plant Mol. Biol. 17: 151–153.
Dolan, L. 2001. How and where to build a root hair. Curr. Opin. Plant Biol. 4: 550–554.
Downey, P., Szabò, I., Ivashikina, N., Negro, A., Guzzo, F., Ache, P., Hedrich, R., Terzi, M. and Lo Schiavo, F. 2000. KDC1, a novel carrot root hair K+ channel. J. Biol. Chem. 275: 39420–39426.
Friml, J., Vieten, A., Sauer, M., Weijers, D., Schwarz, H., Hamann, T., Offringa, R. and Jürgens, G. 2003. Efflux-dependent auxin gradients establish the apical-basal axis of Arabidopsis. Nature 426: 147–153.
Gaymard, F., Pilot, G., Lacombe, B., Bouchez, D., Bruneau, D., Boucherez, J., Michaux-Ferriere, N., Thibaud, J.B. and Sentenac, H. 1998. Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap. Cell 94: 647–655.
Giuliano, G., Rosellini, D. and Terzi, M. 1983. A new method for purification of the different stages of carrot embryoids. Plant Cell Rep. 2: 216–218.
Giuliano, G., Lo Schiavo, F. and Terzi, M. 1984. Isolation and developmental characterization of temperature sensitive carrot cell variants. Theor. Appl. Genet. 67: 179–183.
Goldberg, R.B., Palva, G.D. and Yadegari, R. 1994. Plant embryogenesis: Zygote to seed. Science 255: 605–614.
Hardegger, M. and Sturm, A. 1998. Transformation and regeneration of carrot (Daucus carota L.). Mol. Breed. 4: 119–127.
Hirsch, R.E., Lewis, B.D., Spalding, E.P. and Sussman, M.R. 1998. A role for the AKT1 potassium channel in plant nutrition. Science 280: 918–921.
Hosy, E., Vavasseur, A., Mouline, K., Dreyer, I., Gaymard, F., Poree, F., Boucherez, J., Lebaudy, A., Bouchez, D., Véry, A.A., Simonneau, T., Thibaud, J.B. and Sentenac, H. 2003. The Arabidopsis outward K+ channel GORK is involved in regulation of stomatal movements and plant transpiration. Proc. Natl. Acad. Sci. USA 100: 5549–5554.
Jürgens, G., Torres Ruiz, R.A. and Berleth, T. 1994. Embryonic pattern formation in flowering plants. Annu. Rev. Genet. 28: 351–371.
Laemmli, U.K. 1970. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227: 680–685.
Lenhard, M. and Laux, T. 1999. Shoot meristem formation and maintenance. Curr. Opin. Plant Biol. 2: 44–50.
Maathuis, F. and Sanders, D. 1996. Mechanisms of potassium absorption by higher plant roots. Physiol. Plant. 96: 158–168.
Main, G.D., Reynolds, S. and Gartland, J.S. 1995. Electroporation protocols for Agrobacterium. In: K.M.A. Gartland and M.R. Davey (Eds.), Methods in Molecular Biology, “Agrobacterium protocols” 44: 405–412.
Marten, I., Hoth, S., Deeken, R., Ache, P., Ketchum, K.A., Hoshi, T. and Hedrich, R. 1999. AKT3, a phloem-localized K+ channel, is blocked by protons. Proc. Natl. Acad. Sci. USA 96: 7581–7586.
Mouline, K., Véry, A.A., Gaymard, F., Boucherez, J., Pilot, G., Devic, M., Bouchez, D., Thibaud, J.B. and Sentenac, H. 2002. Pollen tube development and competitive ability are impaired by disruption of a Shaker K+ channel in Arabidopsis. Genes Dev. 16: 339–350.
Neher, E. 1992. Correction for liquid junction potentials in patch clamp experiments. Meth. Enzymol. 207: 123–131.
Paganetto, A., Bregante, M., Downey, P., Lo Schiavo, F., Hoth, S., Hedrich, R. and Gambale, F. 2001. A novel K+channel expressed in carrot roots with a low susceptibility toward metal ions. J. Bioen. Biomemb. 33: 63–71.
Picco, C., Bregante, M., Naso, A., Gavazzo, P., Costa, A., Formentin, E., Downey, P., Lo Schiavo, F. and Gambale, F. 2004 Histidines are responsible for zinc potentiation of the current in KDC1 carrot channels. Biophys. J. 86: 224–234.
Pilot, G., Lacombe, B., Gaymard, F., Chérel, I., Boucherez, J., Thibaud, J.B and Sentenac, H. 2001. Guard cell inward K+channel activity in arabidopsis involves expression of the twin channel subunits KAT1 and KAT2. J. Biol. Chem. 276: 3215–3221.
Reintanz, B., Szyroki, A., Ivashikina, N., Ache, P., Godde, M., Becker, D., Palme, K. and Hedrich, R. 2002. AtKC1, a silent Arabidopsis potassium channel α-subunit modulates root hair K+ influx. Proc. Natl. Acad. Sci. USA 99: 4079–4084.
Rigas, S., Debrosses, G., Haralampidis, K., Vicente-Agullo, F., Feldmann, K.A., Grabov, A., Dolan, L. and Hatzopoulos, P. 2001. TRH1 encodes a potassium transporter required for tip growth in Arabidopsis root hairs. Plant Cell 13: 139–151.
Rutenberg, J., Cheng, S.M. and Levin, M. 2002. Early embryonic expression of ion channels and pumps in chick and Xenopus development. Dev. Dyn. 225: 469–484.
Schiavone, F.M. and Cooke, T.J. 1987. Unusual patterns of somatic embryogenesis in the domesticated carrot: Developmental effects of exogenous auxins and auxin transport inhibitors. Cell Differ. 21: 53–62.
Steeves, T.A. and Sussex, I.M. 1989. Patterns in Plant Development. Cambridge University Press.
Szyroki, A., Ivashikina, N., Dietrich, P., Roelfsema, M.R., Ache, P., Reintanz, B., Deeken, R., Godde, M., Felle, H., Steinmeyer, R., Palme, K. and Hedrich, R. 2001. KAT1 is not essential for stomatal opening. Proc. Natl. Acad. Sci. USA 98: 2917–2921.
Terzi, M. and Lo Schiavo, F. 1990. Somatic embryogenesis. In: S.S. Bhojwani (Ed.), Plant Tissue Culture: Applications and Limitations, Elsevier Science Publishers B.V., Amsterdam, pp. 54–66.
Véry, A.A. and Sentenac, H. 2003. Molecular mechanisms and regulation of K+ transport in higher plants. Annu. Rev. Plant Biol. 54: 575–603.
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Costa, A., Armando, C., Serena, V. et al. Potassium and carrot embryogenesis: Are K+ channels necessary for development?. Plant Mol Biol 54, 837–852 (2004). https://doi.org/10.1007/s11103-004-0236-9
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DOI: https://doi.org/10.1007/s11103-004-0236-9