Auxin Induced Expression of Expansin is Alered in a New Aux1 Allele that Shows Severe Defect in Gravitropic Response

  • Jeong, Hae-Jun (Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University) ;
  • Kwon, Ye-Rim (Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University) ;
  • Oh, Jee-Eun (Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University) ;
  • Kim, Ki-Deok (Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University) ;
  • Lee, Sung-Joon (Department of Food Science, College of Life and Environmental Sciences, Korea University) ;
  • Hong, Suk-Whan (Division of Applied Plant Science, College of Agriculture and Life Sciences, Chonnam National University) ;
  • Lee, Ho-Joung (Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University)
  • Published : 2006.12.31

Abstract

While the underlying molecular mechanism remains to be elucidated, recent studies suggest that polar auxin transport is a key controlling factor in triggering differential growth responses to gravity. Identification of regulatory components in auxin-mediated differential cell expansion would improve our understanding of the gravitropic response. In this study, we identify a mutant designated aux1-like(later changed to aux1), an allele of the aux1 mutant that exhibits a severely disrupted root gravitropic response, but no defects in developmental processes. In Arabidopsis, AUX1 encodes an auxin influx carrier. Since in-depth characterization of the gravitropic response caused by mutations in this gene has been performed previously, we focused on identifying the downstream genes that were differentially expressed compared to wild-type plants. Consistent with the mutant phenotype, the transcription of the auxin-responsive genes IAA17 and GH3 were altered in aux1 plants treated with IAA, 2, 4-D and NAA. In addition, we identified two expansin genes EXP10 and EXPL3 that exhibited different expression in wild-type and mutant plants.

Keywords

References

  1. Friml, J. (2003) Auxin transport-shaping the plant. Curr. Opin. Plant Biol. 6, 7-12 https://doi.org/10.1016/S1369526602000031
  2. Berleth, T. and Sachs, T. (2001) Plant morphogenesis: longdistance coordination and local patterning. Curr. Opin. Plant Biol. 4, 57-62 https://doi.org/10.1016/S1369-5266(00)00136-9
  3. Abel, S. and Theologis, A. (1996) Early genes and auxin action. Plant Physiol. 111, 9-17 https://doi.org/10.1104/pp.111.1.9
  4. Dharmasiri, N. and Estelle, M. (2004) Auxin signaling and regulated protein degradation. Trends Plant Sci. 9, 302-308 https://doi.org/10.1016/j.tplants.2004.04.003
  5. Nemhauser, J. L., Feldman, L. J. and Zambryski, P. C. (2000) Auxin and ETTIN in Arabidopsis gynoecium morphogenesis. Development 127, 3877-88
  6. Harper, R. M., Stowe-Evans, E. L. Luesse, D. R., Muto, H., Tatematsu, K., Watahiki, M. K., Yamamoto, K. and Liscum, E. (2000) The NPH4 locus encodes the auxin response factor ARF7, a conditional regulator of differential growth in aerial Arabidopsis tissue. The Plant Cell 12, 757-770 https://doi.org/10.2307/3870999
  7. Reed, J. W. (2001) Roles and activities of Aux/IAA proteins in Arabidopsis. Trends Plant Sci. 6, 420-425 https://doi.org/10.1016/S1360-1385(01)02042-8
  8. Swarup, R., Kargul, J., Marchant, A., Zadik, D., Rahman, A., Mills, R., Yemm, A., May, S., Williams, L., Millner, P., Tsurumi, S., Moore, I., Napier, R., Kerr, I. D. and Bennett, M. J. (2004) Structure-function analysis of the presumptive Arabidopsis auxin permease AUX1. The Plant Cell 16, 3069-83 https://doi.org/10.1105/tpc.104.024737
  9. Galweiler, L., Guan, C., Muller, A., Wisman, E., Mendgen, K., Yephremov, A. and Palme, K. (1998) Regulation of polar auxin transport by AtPIN1 in Arabidopsis vascular tissue. Science 282, 2226-2230 https://doi.org/10.1126/science.282.5397.2226
  10. Geldner, N., Frimi, J., Stierhof, Y. D., Jurgens, G. and Palme, K. (2001) Auxin transport inhibitors block PIN1 cycling and vesicle trafficking. Nature 413, 425-428 https://doi.org/10.1038/35096571
  11. Swarup, R., Friml, J., Marchant, A., Ljung, K., Sandberg, G., Palme, G. and Bennett, M. J. (2001). Localisation of the auxin permease AUX1 in the Arabidopsis root apex reveals two novel functionally distinct hormone transport pathways. Genes Dev. 15, 2648-2653 https://doi.org/10.1101/gad.210501
  12. Rashotte, A. M., Brady, S. R., Reed, R. C., Ante, S. J. and Muday, G. K. (2000). Basipetal auxin transport is required for gravitropism in roots of Arabidopsis. Plant Physiol. 122, 481-490 https://doi.org/10.1104/pp.122.2.481
  13. Marchant, A., Kargul, J., May, S. T., Muller, P., Delbarre, A., Perrot-Rechenmann, C. and Bennett, M. J. (1999). AUX1 regulates root gravitropism in Arabidopsis by facilitating auxin uptake within root apical tissues. EMBO J. 18, 2066-2073 https://doi.org/10.1093/emboj/18.8.2066
  14. Parry, G., Delbarre, A., Marchant, A., Swarup, R., Napier, R., Perrot-Rechenmann, C. and Bennett, M. J. (2001). Novel auxin transport inhibitors phenocopy the auxin influx carrier mutation aux1. Plant J. 25, 399-406 https://doi.org/10.1046/j.1365-313x.2001.00970.x
  15. Shieh, M. W. and Cosgrove, D. J. (1998) Expansins. J. Plant Res. 111, 149-157 https://doi.org/10.1007/BF02507161
  16. Lee, H., Xiong, L., Gong, Z., Ishitani, M., Stevenson, B. and Zhu, J. K. (2001) The Arabidopsis HOS1 gene negatively regulates cold signal transduction and encodes a RING finger protein that displays cold-regulated nucleocytoplasmic partitioning. Genes Dev. 15, 912-924 https://doi.org/10.1101/gad.866801
  17. Marchant, A. and Bennett M. J. (1998) The Arabidopsis AUX1 gene: a model system to study mRNA processing in plants. Plant Mol. Biol. 36, 463-71 https://doi.org/10.1023/A:1005961303167
  18. Hagen, G. and Guilfoyle, T. (2002) Auxin-responsive gene expression: genes, promoters and regulatory factors. Plant Mol. Biol.49, 373-385 https://doi.org/10.1023/A:1015207114117
  19. Ulmasov, T., Hagen, G. and Guilfoyle, T. J. (1997) ARF1, a transcription factor that binds to auxin response elements. Science 276, 1865-1868 https://doi.org/10.1126/science.276.5320.1865
  20. Ulmasov, T., Hagen, G. and Guilfoyle, T. J. (1999) Activation and repression of transcription by auxin-response factors. Proc. Natl. Acad. Sci. USA 96, 5844-5849
  21. Katekar, G. F. and Giesler, A. E. (1980) Auxin transport inhibitors. IV. Evidence of a common mode of action for a proposed class of auxin transport inhibitors, the phytotropins. Plant Physiol. 66, 1190-1195 https://doi.org/10.1104/pp.66.6.1190
  22. Zhang, N. and Hasenstein, K. H. (2000) Distribution of expansins in graviresponding maize roots. Plant Cell Physiol. 41, 1305-1312 https://doi.org/10.1093/pcp/pcd064