Author
STEVENS, WILLIAM - UNIVERSITY OF MISSOURI | |
Vories, Earl | |
DUNN, DAVID - UNIVERSITY OF MISSOURI | |
RHINE, MATTHEW - UNIVERSITY OF MISSOURI |
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 6/15/2006 Publication Date: 11/12/2006 Citation: Stevens, W., Vories, E. D., Dunn, D., Rhine, M. 2006. Irrigation for vaccine production in pharmaceutical tobacco. ASA-CSSA-SSSA Intl. Annual Meetings. July 9-12, 2006, Portland, Oregan. p.25438. Interpretive Summary: Technical Abstract: Biotechnology companies in North America and Europe have engineered plants to produce recombinant proteins for therapeutic drugs and vaccines. Chlorogen, Inc. located in St. Louis, Missouri, inserted the protective antigen (PA) gene from Bacillus anthracis into tobacco (Nicotiana tabacum cv LAMD 609)) chloroplasts to make an anthrax vaccine. The objective of a glasshouse study at the University of Missouri was to determine the optimum soil water content for producing PA in tobacco leaves. Tests were conducted from December 2004 to February 2006. Plants were grown from non-transgenic seeds and the same cultivar with the PA transgene. In one experiment, seedlings were grown in pots to the button growth stage when daily watering was stopped. Plant size significantly affected transpiration. Plants expressing PA were smaller, and continued to transpire one day longer than control plants due to greater residual water in potting medium. In a separate experiment, LAMD:PA seedlings were transplanted to native soil (fine-loamy, mixed, thermic Typic Argiudolls) in the glasshouse floor. Treatments consisted of soil water potential irrigation thresholds (-20, - 34, -48, and -62 kPa). Soil moisture sensors were buried 10 cm and micro-sprinklers used for irrigation. A ratoon system with two harvests was used. The -34 kPa soil water potential treatment produced the highest leaf yield and PA concentrations. Using ELISA quantification, this treatment averaged 529 µg PA kg-1 leaf fresh weight for the two harvests. Other treatments averaged 163 to 261 µg PA kg-1 leaf fresh weight. |