Dr. Sharman D. O'Neill, M.A., Ph.D.

Dr. Sharman D. O'Neill, M.A., Ph.D.

Position Title
Professor Emerita & Director VGDC

Department of Plant Biology, College of Biological Sciences
Vanilla Genetic Diversity Center

2253 Life Sciences Building

Research Interests

Plant Reproduction, Development and Biodiversity

Our research focuses on the molecular basis of plant reproductive development and shoot apical meristem development. My laboratory has focused on three major areas: (1) analysis of the role of key transcription factors, such as the homeobox genes ATML1 and WUS, and the F-Box genes, such as ATSKP1, and hormones during post-zygotic plant growth and development using the model genetic system Arabidopsis, (2) pollination of flowers and postpollination ovary and fruit development using Phalaenopsis and Vanilla orchids (Orchidaceae), and (3) the photoperiodic control of flowering in the photoperiodic short-day plant, Pharbitis nil, the Japanese morning glory. Currently, we are engaged in multidisciplinary collaborative research on Vanilla planifolia and its Mesoamerican wild crop relatives (Vanilloideae, Orchidaceae) to study flower and fruit development, disease resistance (Fusarium), and critical issues facing small-holder farmers in food insecure and impoverished developing nations. We also maintain a collection of rare and endangered Vanilla species from four continents, including Vanilla planifolia wild-crop germplasm collected from the region of its evolutionary origin and related Vanilla species of Mesoamerican and South American origin.

Grad Group Affiliations

  • Plant Biology
  • Horticulture and Agronomy
  • Agricultural and Environmental Chemistry

Specialties / Focus

  • Molecular Biology, Biochemistry, and Genomics
  • Developmental Biology
  • Gene Regulation
  • Genomics
  • Molecular Genetics
  • Plant Molecular Biology
  • Signal Transduction
  • Orchid Biology and Conservation 


  • O'Neill Lab Group

Field Sites

  • UC Davis Center for Diversity- Vanilla Genetic Diversity Center, CBS Orchard Park Greenhouse Complex

Honors and Awards

  • World Orchid Congress, First Prize Science Poster Award, 2017
  • General Mills Vanilla Sustainability Challenge Award, 2011
  • NIOC Scientific Research Award, 1994
  • National Science Foundation Research Fellowship in Molecular Biology Award, 1984-1988

    Professional Societies

    • American Association for the Advancement of Science
    • American Society of Plant Biologists
    • Association for Practical and Professional Ethics
    • Public Responsibility in Medicine & Research
    • Society for the Advancement of Chicanos and Native Americans in Science


    • Cornell University 1982 Ph.D.
    • Smith College 1975 M.A.


    O'Neill, SD, Bui, AQ, Potter, D, Zhang, XS (2018) Pollination of orchid flowers: Quantitative and domain-specific analysis of ethylene biosynthetic and hormone-induced gene expression. International Journal of Plant Sciences 178:188-210.

    O'Neill, SD (2016) Plant Biology. Major Reference Works in the Life Sciences. Elsevier, Inc. Oxford, England, UK.

    Su, HS, Zhao, XY, Liu, YB, Zhang, CL, O’Neill, SD, and Zhang, XS (2009) Auxin-induced WUS expression is essential for somatic embryogenesis in Arabidopsis. The Plant Journal doi: 10.1111/j.1365-313X.2009.03880.x..

    Zheng, CC, Potter, D., and O’Neill, S.D. (2009) Phytochrome gene expression and phylogenetic analysis in the short-day plant Pharbitis nil Choisy (Convolvulaceae): differential regulation by light and an endogenous clock. American Journal of Botany 96:1319-1336.

    Lu, P., Porat, R., Nadeau, J. A. and O’Neill, S. D. 1996. Identification of a meristem L1 layer-specific gene in Arabidopsis that is expressed during embryonic pattern formation and defines a new class of homeobox genes. The Plant Cell 8: 2155-2168.

    Porat, R., Lu, P., and O’Neill, S. D. 1998. Arabidopsis SKP1, a homologue of a cell cycle regulator gene, is predominantly expressed in meristematic cells. Planta 204: 345-351.

    Nadeau, JA, Zhang, XS, Li, J, and O'Neill, SD. 1996. Ovule development: identification of stage-specific and tissue-specific cDNAs. The Plant Cell 8:213-239.

    Zhang, XS, and O'Neill, SD. 1993. Ovary and gametophyte development are coordinately regulated by auxin and ethylene following pollination. The Plant Cell 5:403-418

    Porat, R, Nadeau, JA, Kirby, J, Sutter, E, and O’Neill, SD. 1998. Characterization of the primary pollination signal in the postpollination syndrome of Phalaenopsis flowers. Plant Growth Regul. 24:109-117