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Mark Estelle


The plant hormone auxin has been implicated in virtually every stage of plant growth and development from embryogenesis to senescence. My laboratory is using the genetically tractable plant Arabidopsis thaliana to identify and characterize auxin response pathways. Our work has shown that auxin promotes the rapid degradation of a family of transcriptional repressors called the Aux/IAA proteins via the ubiquitin proteasome pathway. Auxin interacts directly with a ubiquitin protein ligase called SCFTIR1, and promotes an interaction between the E3 and the Aux/IAAs. We are now studying the mechanism SCFTIR1 action and the role of the complex in various aspects of plant growth. In addition, we are turning our attention to the complex transcriptional networks that mediate auxin growth responses. Our ultimate goal is to understand the systems that mediate auxin-dependent development at the level of the cell and organism.


  • Calderón Villalobos, L.I.A., Lee, S., Brandt, W., Armitage, L., Sheard, L. B., Tan, X., Parry, G., Mao, H., Zheng, N., Napier, R., Kepinski, S., and M. Estelle. 2012. TIR1/AFBs and Aux/IAAs constitute a combinatorial co-receptor system to perceive auxin with differential sensitivities. Nat. Chem. Biol. 8:477-485
  • Chapman, E.C., Greenham, K., Castillejo, C., Sartor, R., Bialy, A., Sun, T-p & Mark Estelle, 2012. Hypocotyl Transcriptome Reveals Auxin Regulation of Growth-Promoting Genes Through GA-Dependent and -Independent Pathways, PLoS ONE, 7(5):e36210.
  • Shani, E., Weinstain, R., Zhang, Y., Castillejo Mangado, C., Kaiserli, E., Chory, J., Tsien, R.Y., and M. Estelle. 2013. Gibberellins accumulate in the elongating endodermal cells of Arabidopsis roots. Proc., Natl. Acad. Sci. USA 110:4834-9
  • Yu H, Karampelias M, Robert S, Peer WA, Swarup R, Ye S, Ge L, Cohen J, Murphy A, Friml J, and Mark Estelle. 2013. ROOT ULTRAVIOLET B-SENSITIVE1/weak auxin response3 is essential for polar auxin transport in Arabidopsis. Plant Physiol.162:965-76
  • Yu, H., Moss, B., Jang, Michael Prigge, S.S., Klavins, E., Nemhauser, J., and Mark Estelle. 2013. Mutations in the TIR1 auxin receptor that increase affinity for Aux/IAA proteins result in auxin hypersensitivity, Plant Phys. 162(1):295-303
  • Bargmann, B.O.R., Vanneste, S., Krouk, G., Nawy, T., Efroni, I., Shani, E., Choe, C., Friml, J., Estelle, M., and K. D. Birnbaum, 2013. A map of cell-type specific auxin responses. Mol. Syst. Biol. 9:688
  • Yu, H., Zhang, Y., Moss, B.L., Bargmann, B.O.R., Wang, R., Prigge, M., Nemhauser, J.L., Estelle, M. 2015. 2015 Untethering the TIR1 auxin receptor from the SCF complex increases its stability and inhibits auxin response. Nature Plants. doi:10.1038/nplants.2014.30
  • Gao, Y1., Zhang, Y1., Zhang, D1., Dai, X., Estelle, M2., and Zhao, Y2. 2015. Auxin Binding Protein 1 (ABP1) is not required for either auxin signaling or Arabidopsis development. Proc. Nat. Acad. Sci. 112(7):2275-80. doi: 10.1073/pnas.1500365112.
    1 contributed equally; 2 co-corresponding author
  • Ripoll, J.J., Bailey, L., Mai, Q-A., Wu, S., Hon, C., Chapman, E., Ditta, G., Estelle, M., and Yanofsky, M. 2015 MicroRNA regulation of fruit growth. Nature Plants. doi:10.1038/nplants.2015.36
  • Wang, R., Zhang, Y., Kieffer, M., Yu, H., Kepinski, S., and Estelle, M. HSP90 regulates temperature-dependent seedling growth in Arabidopsis by stabilizing the auxin co-receptor F-box protein TIR1. Nature Communications, DOI: 10.1038/ncomms10269