You have full text access to this OnlineOpen article

A small acidic protein 1 (SMAP1) mediates responses of the Arabidopsis root to the synthetic auxin 2,4-dichlorophenoxyacetic acid

  1. Abidur Rahman1,2,
  2. Akari Nakasone1,5,†,
  3. Tory Chhun4,
  4. Chiharu Ooura3,‡,
  5. Kamal Kanti Biswas1,§,
  6. Hirofumi Uchimiya3,5,
  7. Seiji Tsurumi4,
  8. Tobias I. Baskin2,
  9. Atsushi Tanaka1,†,
  10. Yutaka Oono1,3,†,*

Article first published online: 27 JUL 2006

DOI: 10.1111/j.1365-313X.2006.02832.x

Issue

The Plant Journal

The Plant Journal

Volume 47, Issue 5, pages 788–801, September 2006

Additional Information

How to Cite

Rahman, A., Nakasone, A., Chhun, T., Ooura, C., Biswas, K. K., Uchimiya, H., Tsurumi, S., Baskin, T. I., Tanaka, A. and Oono, Y. (2006), A small acidic protein 1 (SMAP1) mediates responses of the Arabidopsis root to the synthetic auxin 2,4-dichlorophenoxyacetic acid. The Plant Journal, 47: 788–801. doi: 10.1111/j.1365-313X.2006.02832.x

Author Information

  1. 1

    Research Group for Plant Resource Application, Japan Atomic Energy Research Institute, Takasaki 370-1292, Japan,

  2. 2

    Biology Department, University of Massachusetts, Amherst, MA 01003, USA,

  3. 3

    Advanced Science Research Center, Japan Atomic Energy Research Institute, Takasaki 370-1292, Japan,

  4. 4

    Center for Supports to Research and Education Activities Isotope Division, Kobe University, Kobe 657-8501, Japan, and

  5. 5

    Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan

  1. †

    Present address: Radiation-Applied Biology Division, Japan Atomic Energy Agency, Takasaki, 370-1292, Japan.

  2. ‡

    Present address: Methodology Research Group, Research Development Division, Fujirebio Inc., Hachioji, Tokyo 192-0031, Japan.

  3. §

    Present address: Department of Environmental Life Sciences, Tohoku University, Sendai 980-8577, Japan.

* *(fax +81 27 346 9688; e-mail ohno.yutaka@jaea.go.jp).

Publication History

  1. Issue published online: 27 JUL 2006
  2. Article first published online: 27 JUL 2006
  3. Received 3 March 2006; revised 11 May 2006; accepted 30 May 2006.

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article with Supporting Information (HTML) Get PDF (1405K)

Keywords:

  • anti-auxin;
  • Arabidopsis thaliana;
  • indole-3-acetic acid (IAA);
  • p-chlorophenoxy-isobutyric acid (PCIB);
  • signal transduction

Summary

2,4-dichlorophenoxyacetic acid (2,4-D), a chemical analogue of indole-3-acetic acid (IAA), is widely used as a growth regulator and exogenous source of auxin. Because 2,4-D evokes physiological and molecular responses similar to those evoked by IAA, it is believed that they share a common response pathway. Here, we show that a mutant, antiauxin resistant1 (aar1), identified in a screen for resistance to the anti-auxin p-chlorophenoxy-isobutyric acid (PCIB), is resistant to 2,4-D, yet nevertheless responds like the wild-type to IAA and 1-napthaleneacetic acid in root elongation and lateral root induction assays. That the aar1 mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the DR5:GUS and HS:AXR3NT-GUS backgrounds, as well as by real-time PCR quantification of IAA11 expression. The two characterized aar1 alleles both harbor multi-gene deletions; however, 2,4-D responsiveness was restored by transformation with one of the genes missing in both alleles, and the 2,4-D-resistant phenotype was reproduced by decreasing the expression of the same gene in the wild-type using an RNAi construct. The gene encodes a small, acidic protein (SMAP1) with unknown function and present in plants, animals and invertebrates but not in fungi or prokaryotes. Taken together, these results suggest that SMAP1 is a regulatory component that mediates responses to 2,4-D, and that responses to 2,4-D and IAA are partially distinct.

View Full Article with Supporting Information (HTML) Get PDF (1405K)