Research Statement

We use Arabidopsis as our model system, and a decade ago we carried out screens to identify mutants with defects in patterning of the leaf vascular system.  This screen yielded a rich assortment of mutants, and resulted in two major funded projects in my lab.  One project centers around the bypass1 (bps1) mutant, whose characterization led us to identify a root-to-shoot signaling pathway that appears to involve a novel signaling molecule with properties resembling a plant hormone.  We are currently working to identify the signaling molecule, its role in shoot development, and to characterize the cell biology of BPS1 proteins.   The other project arose from characterization of varicose (vcs) and trident (tdt) mutants, which have defects in mRNA decapping components.  Decapping removes the protective 7-methyl guanine nucleotide attached by a 5’-5’ triphosphate linkage (the cap) from mRNAs, which initiates 5’-to-3’ decay.  Traditionally the major model for mRNA decay, and especially decapping, has been yeast (Saccharomyces cerevisiae).  However, the decapping complex of both plants and animals contain a large scaffold (VCS) that is missing from yeast, and this plant/animal complex also carries out additional miRNA-related functions.   Our contributions to this field include the first demonstration that general cytoplasmic mRNA decay pathways have substrate specificity, elucidating roles for the decapping complex in miRNA directed translational regulation,  and identification of a novel cytoplasmic mRNA decay pathway that is conserved in plants and animals (but again missing in yeast).
 

Research Keywords

  • metabolomics
  • RNA biology
  • Plant Biology
  • Genetics
  • Developmental Genetics
  • Developmental Biology
  • Biochemistry
  • Gene Expression

Presentations

  • KSAB International Conference on Plant Molecular Biology, PyongChang, South Korea. Invited Talk/Keynote, Presented, 08/2015.
  • University of Florida, Institute of Genetics. Invited Talk/Keynote, Presented, 03/2015.
  • Korean Society for Agricultural Biochemistry, 50th Year Conference. Invited Speaker Long Distance Signaling in Plants. Invited Talk/Keynote, Presented, 10/2010.
  • Yonsei University Seminar Long-Distance Signaling in Plants: the BPS1 protein is a negative regulator. Presentation, Presented, 10/2010.

Publications

  • Lee, D.H., Parrott, D.L., Adhikari, E., Fraser, N., and Sieburth, L.E. The mobile bypass Signal Arrests Shoot Growth by disrupting SAM Maintenance, Cytokinin Signaling, and WUS Expression. 2016. Plant Physiology, 171: 2178-2190. Published, 05/12/2016.
  • Carlos Perea-Resa, Cristian Carrasco-López1, Rafael Catalá, Veronika Turečková, Ondrej Novak, Weiping Zhang, Leslie Sieburth, José Manuel Jiménez-Gómez and Julio Salinas. 2016. The Lsm1-7 Complex Controls Plant Adaptation To Adverse Environmental Conditions By Promoting Selective mRNA Decapping. Plant Cell. 28: 505 – 520. Published, 01/13/2016.
  • Roux, M.E., Rasmussen, M.W., , Palma, K., Lolle, S., Regué, AM., Bethke, G., Glazebrook, J., Zhang, W., Sieburth, L, Larsen, M.R., Mundy, J., and Petersen, M. 2015. The mRNA decay factor PAT1 functions in a pathway including MAP kinase 4 and immune receptor SUMM2. EMBO J. 34: 593-608. Published, 06/2015.
  • Adhikari, E., Lee, D.-K., Giavalisco, P., and Sieburth, L.E. 2013. Long-distance signaling in bypass1 mutants: bioassay development reveals the bps signal to be a metabolite. Molecular Plant. 6 (1): 164-173. Published, 06/2013.
  • Lee, Dong-Keun, Van Norman, J. M, Murphy, C., Adhikari, E., Reed, J. W., Sieburth, L. E. 2012. In the absence of BYPASS1-related gene function, the bps signal disrupts embryogenesis by an auxin-independent mechanism. Development 139: 805-815. Released, 08/2012.
  • Lee, D-K, and Sieburth, L.E. 2012. Article Addendum: The bps signal: Embryonic arrest from an auxin-independent mechanism in bypass triple mutants. Plant Signaling & Behavior. 7:698-700. Published, 06/2012.
  • Zhang, W., Murphy, C., Sieburth, L. E. 2010. Conserved RNaseII domain protein functions in cytoplasmic mRNA decay and suppresses Arabidopsis decapping mutant phenotypes. Proc. Natl. Acad. Sci. USA. 107: 1598. Published, 09/2011.
  • Van Norman, J.M., Murphy, C. Sieburth, L.E. 2011. BYPASS1: synthesis of the mobile root-derived signal requires active root growth and arrests early leaf development. BMC Plant Biol. 11:28. Published, 02/2011.
  • Lee, D.L., and Sieburth, L.E. 2010. Plasmodesmata Formation: poking holes in walls with ise. Curr. Biol. In press. In press, 12/2010.
  • Sieburth, L.E., and Lee, D.K. 2010. BYPASS1: How a Tiny Mutant Tells a Big Story about Root-to-shoot Signaling. J. Integrative Plant Biol. 52:77-85. Published, 01/2010.