Biology

Jerry Pullman, Professor

Ph.D., Plant Pathology, University of California at Davis, 1979

Phone: 404-894-5307
Fax: 404-894-4778
Office: IPST 590

Research Interests

Plant embryo and seed development; somatic embryogenesis, clonal propagation, plant tissue culture for rare and endangered coniferous species

See my page at IPST for additional publications and a list of U.S. Patents.

Current Research

Forest productivity can be increased by planting tree farms with fast-growing high-value trees. To take better advantage of long-term breeding programs and genetic engineering advances that produce more lumber, pulp and paper, energy, or chemicals from renewable tree biomass, methods to propagate large numbers of superior trees are needed. As demands for forest products grow and the land base to produce trees shrinks, it will become difficult for the U.S. forest products industry to remain globally competitive. Clonal propagation by somatic embryogenesis (SE) can help capture benefits of breeding or genetic engineering to improve wood quantity, quality, and uniformity.

Loblolly pine is the major species planted across the Southern U.S. with 1 to 1.5 billion trees planted annually. Forest productivity can be increased by planting tree farms with large numbers of elite, high-value trees. Sexual production of trees yields trees with variable characteristics. Methods to propagate large numbers of genetically superior conifer trees are needed. Clonal propagation technology is expected to play a major role in future reforestation of loblolly pine and other coniferous species if costs are acceptable and if a high-enough percentage of high-value genotypes can be successfully propagated and established in the plantation setting.

The research interests of Jerry and his team are in the areas of the multiplication of high-value trees through somatic embryogenesis, understanding the fundamental physical and chemical factors driving natural plant embryo development, and the creation of tissue culture systems necessary for the genetic engineering of forest trees. We are currently focusing on improving development of loblolly pine (Pinus taeda L.) late-stage somatic embryos by studying the natural osmoticants (organic acids, sugars, peptides and soluble proteins) feeding the embryo during development and duplicating this environment in vitro. We are also interested in propagation of rare and endangered coniferous species through SE.

Recent Publications

  1. Pullman G. S, S. Johnson and K. Bucalo. Douglas fir embryogenic tissue initiation. Plant Cell Organ and Tissue Culture, in press (accepted 10-01-08).
  2. Pullman G. S., Chase K-M, A. Skryabina and K. Bucalo. Conifer embryogenic tissue initiation: Improvements by supplementation of medium with D-chiro-inositol and D-xylose. Tree Physiology, in press (accepted 9-10-08).
  3. Pullman, G. S. and M. Buchanan. 2008. Identification and quantitative analysis of stage-specific sugars and carbohydrates in loblolly pine (Pinus taeda L.) zygotic embryo and female gametophyte. Tree Physiology 28: 985-996.
  4. Oh, T., R. M. Wartell, J. Cairney and G. S. Pullman. 2008. Evidence for stage-specific modulation of specific microRNAs (miRNAs) and miRNA processing components in zygotic embryo and female gametophyte tissues during embryogenesis of loblolly pine (Pinus taeda L). New Phytologist 179: 67-80.
  5. DeSilva, V., D. Bostwick, K. L. Burns, C. D. Oldham, A. Skryabina, M. C. Sullards, D. Wu, Y. Zhang, S. W. May and G. S. Pullman. 2008. Isolation and characterization of a molecule stimulatory to growth of early-stage somatic embryos from early-stage female gametophyte tissue of loblolly pine. Plant Cell Reports. 27: 633-646.
  6. Cairney, J. and G. S. Pullman. 2007. Gene expression during embryogenesis in conifers. New Phytologist 176: 511-536. (Invited Tansley Review).
  7. Pullman, G. S. and A. Skryabina. 2007. Liquid medium and liquid overlays improve embryogenic tissue initiation in conifers. Plant Cell Reports. 26: 873-887.
  8. Vales, T., X. Fang, L. Ge, N. Xu, J. Cairney, G. S. Pullman, and G. F. Peter. 2007. Improved somatic embryo maturation in loblolly pine by monitoring ABA-responsive gene expression. Plant Cell Reports 26: 133-143.
  9. Cairney, J., L. Zheng, A. Cowels, J. Hsiao, V. Zismann, J. Liu, S. Ouyang, F. Thibaud-Nissen, J. Hamilton, K. Childs, G. S. Pullman, Y. Zhang, T. Oh, T., and R. Buell. 2006. Expressed sequence tags from loblolly pine embryos reveal similarities with angiosperm embryogenesis. Plant Molecular Biology 62: 485-501.
  10. MacKay J., M. Becwar, Y. Park, C. Perfetti, J. Cordero, L. Lockart and G. S. Pullman. 2006. Genetic control of SE initiation in LP and implications for breeding. Tree Genetics and Genomes 2: 1-9.
  11. Pullman G. S., M. Buchanan (2006) Identification and quantitative analysis of stage-specific organic acids in loblolly pine (Pinus taeda L.) zygotic embryo and female gametophyte. Plant Science 170:634-647. 
  12. Pullman G. S., R. Chopra, K-M. Chase (2006) Loblolly pine (Pinus taeda L.) somatic embryogenesis:  Improvements in embryogenic tissue initiation by supplementation of medium with organic acids, Vitamins B12, and E. Plant Science 170:648-658.
  13. Pullman, G. S., PK Gupta, R Timmis, C Carpenter, M Kreitinger, E Welty. (2005) Improved Norway spruce somatic embryo development through the use of abscisic acid combined with activated carbon. Plant Cell Reports 24: 271-279.
  14. Van Winkle, S. C. and G. S. Pullman. (2005) Achieving Desired Plant Growth Regulator Levels in Liquid Plant Tissue Culture Media that Include Activated Carbon.  Plant Cell Reports, 24: 201-208.
  15. Toering, A. and G. S. Pullman (2005) Modeling Available 2,4-Dichlorophenoxyacetic acid in a Tissue Culture Medium Containing Activated Carbon. Plant Cell, Organ and Tissue Culture, 82: 179-188.
  16. Pullman, G. S., S. Johnson, S. Van Tassel, and Y. Zhang. (2005) Somatic embryogenesis in loblolly pine (Pinus taeda L.) and Douglas fir (Pseudostuga menziesii (Mirb) Franco): Improving culture initiation with MES pH buffer, biotin, and folic acid. Plant, Cell, and Organ Tissue Culture 80: 91-103.
  17. Pullman, G. S., J. Mein, S. Johnson, and Y. Zhang. (2005) Gibberellin inhibitors improve embryogenic tissue initiation in conifers.  Plant Cell Reports. 23: 596-605.
  18. Van Winkle, S., and G. S. Pullman. 2003. The Combined Impact of pH and Activated Carbon on the Elemental Composition of Plant Tissue Culture Media. Plant Cell Reports 22: 303-311.
  19. Pullman, G. S., Y. Zhang and B. H. Phan. 2003. Brassinolide improves embryonic tissue initiation in conifers and rice. Plant Cell Reports 22:96-104
  20. Pullman, G. S., K. Namjoshi, and Y. Zhang. 2003. Somatic embryogenesis in Loblolly pine (Pinus taeda L.): Improving culture initiation with abscisic acid, silver nitrate, and cytokinins adjustments. Plant Cell Reports 22:85-95.
  21. Van Winkle, S., S. Johnson, and G. S. Pullman. 2003. The impact of Gelrite and activated carbon on the elemental composition of plant tissue culture media. Plant Cell Reports 21:1175-1182.
  22. Pullman, G. S. and M. Buchanan. 2003. Loblolly pine (Pinus taeda L.): Stage-specific elemental analyses of zygotic embryo and female gametophyte tissue. Plant Science 164:943-954.
  23. Pullman, G. S., P. Montello, J. Cairney, N. Xu, and X. Feng. 2003. Loblolly pine (Pinus taeda L.) somatic embryogenesis: Maturation improvements by metal analyses of zygotic and somatic embryos. Plant Science 164:955-969.
  24. Pullman, G., S. Johnson, G. Peter, J. Cairney, and N. Xu. 2003. Improving loblolly pine somatic embryo maturation: Comparison of somatic and zygotic embryo morphology, germination, and gene expression. Plant Cell Reports 21:747-758.