William J. Lucas

William Lucas

Position Title
Distinguished Professor Emeritus

Department of Plant Biology, College of Biological Sciences

1225 Life Sciences

Research Interests

Our lab is interested in the evolution and function of plasmodesmata, the intercellular organelle of the plant kingdom that mediates in both nutrient delivery and cell-to-cell signaling of information macromolecules, including transcription factors and RNA-protein complexes. We are also working on cellular and molecular aspects of virus infection involving transport of infectious RNA/DNA through plasmodesmata, during local infection, and long-distance movement of virus through the phloem for systemic infection within the plant. A major current focus of our lab is the isolation and characterization of the proteins that constitute the supramolecular structure of plasmodesmata.These studies are providing insights into the mechanisms involved in the selective trafficking of proteins/RNA that contribute to supracellular control over plant growth and development. A second emphasis in the lab involves studies on the role of the plant vascular system, and the phloem in particular, as an information superhighway for the delivery of proteins and ribonucleoprotein complexes involved in regulating developmental events in distantly located tissues and organs.

Grad Group Affiliations

  • Integrative Genetics and Genomics
  • Plant Biology

Specialties / Focus

  • Cell and Developmental Biology
  • Environmental and Integrative Biology
  • Model Plants
  • Molecular Biology, Biochemistry and Genomics


  • PLB 111 Plant Physiology, Fall
  • PLB 123 Plant-Virus-Interactions, Fall


  • Lucas Lab http://www-plb.ucdavis.edu/labs/lucas/

Honors and Awards

  • Martin Gibbs Medal awarded by ASPB
  • Francqui Medal awarded by the Belgian Francqui Foundation
  • French Academy of Sciences, elected foreign member
  • Fellow of the American Society of Plant Biologists (2007)
  • Fellow of the American Association for the Advancement of Science (2004)

    Professional Societies

    • American Society for Plant Biology
    • Australian Society for Plant Sciences
    • American Association for the Advancement of Science


    • 1971 BS Physical and Inorganic Chemistry and Plant Biology University of Adelaide
    • 1975 PhD Plant Biophysics University of Adelaide
    • 1990 D.Sc. University of Adelaide


    Lough, T. J. and Lucas, W. J. 2006. Integrative plant biology: role of phloem long-distance macromolecular trafficking. Annu. Rev. Plant Biol. 57:203-232.

    Lin, M.-K., Belanger, H. Lee,Y.-J., Varkonyi-Gasic, E., Taoka, K.-I., Miura, E., Xoconostle-Cázares, B., Gendler, K., Jorgensen, R.A., Phinney, B., Lough T.J., and Lucas, W.J. 2007. FT protein may act as the long-distance florigenic signal in the cucurbits. Plant Cell 19:1488-1506.

    Taoka, K.-I., Ham, B.-K., Xoconostle-Cazares, B., Rojas, M.R., and Lucas, W.J. 2007. Reciprocal phosphorylation and glycosylation recognition motifs control NCAPPl interaction with pumpkin phloem proteins and their cell-to-cell movement. Plant Cell 19:1866-1884.

    Lin, M.-K., Lee, Y.-J., Lough, T.J., Phinney, B.S., and Lucas, W.J. 2009 Analysis of the pumpkin phloem proteome provides functional insights into angiosperm sieve tube function. Mol. Cell. Proteomics 8:343-356.

    Ham, B.K., Brandom, J., Xoconostle-Cazares, B., Ringgold, V., Lough, T.J., and Lucas, W.J. 2009 Polypyrimidine tract binding protein, CmRBP50, forms the basis of a pumpkin phloem ribonucleoprotein complex. Plant Cell 21:197-215.

    Huang, s., Li, R., Zhang, Z., Li, L., Gu, X., Fan, W., Lucas, W.J., et al. 2009 The genome of the cucumber, Cucumis sativus L. Nature Genetics 41: 1275-1281.

    Lucas, W.J., Ham, B.-K., and Kim, J.-Y. 2009 Plasmodesmata – bridging the gap between neighboring plant cells. Trends in Cell Biology, 19: 495-503.

    Li, P., Ham, B.K., and Lucas, W.J. 2011 CmRBP50 phosphorylation is essential for assembly of a stable phloem-mobile high-affinity ribonucleoprotein complex. J. Biol. Chem. 286: 23142-23149.


    Zhou, Y., Rojas, M.R., Park, M.-R., Seo, Y.-S., Lucas, W.J., and Gilbertson, R.L. 2011 Histone H3 interacts and co-localizes with the nuclear shuttle protein and movement protein of a geminivirus. J. Virology 85: 11821-11832.

    Ham, B.-K., Li, G., Kang, B.-H., Zeng, F. and Lucas, W.J. 2012 Over-expression of Arabidopsis plasmodesmata germin-like proteins (PDGLPs) disrupts root growth and development. Plant Cell 24:3630-3648.

    Guo, S., Zhang, J., Sun, H., Salse, J., Lucas, W.J., et al. 2013 The draft genome of watermelon (Citrullus lunatus) and resequencing of 20 diverse accessions. Nature Genetics 45:51-58.

    Qi, J., Liu, X., Zhang, Shen D., Miao, H., Xie, B., Li, X., Zeng, P., Wang, P., Shang Y., Gu, X., Du, Y., Li, Y., Tao Lin, Yuan, J., Yang, X., Chen,    J., Chen, H., Xiong, X., Huang, K., Fei, Z., Mao, L., Tian, L., Städler, T., Renner, S.S., Kamoun, S., Lucas, W.J., Zhang Z. and Huang S. 2013 A cucumber genomic variation map provides insights into the genetic basis of domestication and diversity. Nature Genetics 45:1510-1515.

    Yoo, S.C., Chen, C., Rojas, M., Daimon, Y., Ham, B.-K., Araki, T. and Lucas, W.J. 2013 Phloem long-distance delivery of FLOWERING LOCUS T (FT) to the apex. Plant Journal 75:456-468.

    Chen H, Ahmad M, Rim Y, Lucas WJ, Kim J-Y. 2013 Evolutionary and molecular analysis of Dof transcription factors identified a conserved motif for intercellular protein trafficking. New Phytologist 198:1250-1260.

    Lucas, W.J., Groover, A., Lichtenberger, R., Furuta, K., Yadav, S.R., Helariutta, Y., He, X.-Q., Fukuda, H., Kang, J., Brady, S.M., Patrick, J.W., Sperry, J., Yoshida, A., López-Millán, A.-F., Grusak, M.A. and Kachroo, P. 2013 The plant vascular system: Evolution, Development and Functions. J. Integrative Plant Biol. 55:294-388.

    Ham, B.-K., and Lucas, W.J. 2013 The angiosperm phloem sieve tube system: A role in mediating traits important to modern agriculture. J. Experimental Botany 65:1799-1816

    Han, X., Hyun, T.K., Zhang, M., Koh, E., Kang, B.H., Lucas, W.J. and Kim, J.Y. 2014 Auxin-callose mediated plasmodesmal gating is essential for effective auxin gradient formation and signaling. Developmental Cell 28:132-146.

    Zhang, Z., Liao, H. and Lucas, W.J. 2014 Molecular mechanisms underlying phosphate sensing, signaling and adaptation in plants. J. Integrative Plant Biol. 56:192-220.

    Uddin, M., Dunoyer, P., Schott, G., Akhter, S., Shi, C., Lucas, W.J., Voinnet, O. and Kim, J.Y. 2014 The protein kinase TOUSLED facilitates RNAi in Arabidopsis. Nucleic Acids Research 42:7971-7980.

    Wang, C.-Y., Zhang, S., Yua, Y., Luo, Y.-C., Liu, Q., Ju, C., Zhang, Y.-C., Qu, L.-H., Lucas, W.J., Wang, X. and Chen, Y.Q. 2014 MiR397b Regulates both lignin content and seed number in Arabidopsis via modulating a laccase involved in lignin biosynthesis. Plant Biotechnology Journal 12:1132-1142.

    Ham, B.K., Li, G., Jia, W., Fei, Z., Leary, J.A. and Lucas, W.J. 2014 A pumpkin phloem small RNA-binding protein-ribonucleoprotein complex functions in delivery of small RNAs to sink tissues. Plant Journal 80:683-694.

    Shang, Y., Ma, M., Zhou, Y., Zhang, H., Duan, L., Chen, H., Zeng, J., Wang, S., Gu, W., Zhou, Q., Gu, X., Yasukawa, K., Bouwmeester, H.J., Yang, Q., Qi, X., Lucas, W.J. and Huang, S. 2014 Biosynthesis, regulation, and domestication of bitterness in cucumber. Science 346:1084-1088.

    Spiegelman, Z., Ham, B.-K., Zhang, Z., Toal, T., Brady, S., Fei, Z., Lucas, W.J. and Wolf, S. 2015 A phloem-mobile protein regulates shoot:root ratio by mediating auxin response in distant organs. Plant Journal 83: 853-863.

    Zhu, X., Liang, W., Cui, X., Chen, M., Yin, C., Luo, Z., Zhu, J., Lucas, W.J., Wang, Z., and Zhang, D. 2015 Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther, a MYB domain protein. Plant Journal 82:570-581.