Submitted to: Molecular Breeding of Forage and Turf Conference
Publication Type: Abstract Only
Publication Acceptance Date: May 19, 2003
Publication Date: May 19, 2003
Citation: Gebeyaw, M.T., Denton, M.D., Samac, D.A., Vance, C.P. 2003. Alfalfa for biopharmaceuticals?. Molecular Breeding of Forage and Turf Conference. Available: https://www.register-for.com/mbft/AbstractView.Asp?AbstractId=Abstract29fd Technical Abstract: Alfalfa (Medicago sativa L.) is the fourth most important feed and cash crop in the U.S. where it is used as hay, silage, and to a lesser extent as a grazing crop. The availability of lines that can be easily transformed with Agrobacterium tumefaciens and easily regenerable in tissue culture, makes alfalfa more responsive to genetic engineering and biotechnology, thereby providing the opportunity to develop value-added products and new uses for alfalfa. Because crops can be propagated at larger scale, genetically engineered plants offer unique advantages in the production of recombinant proteins of biopharmaceutical and industrial value than other recombinant protein systems. However, widespread use of transgenic plants has been hampered by low product accumulation and difficulties in the extraction and purification of recombinant proteins from plant tissues. We produced transgenic alfalfa containing endochitinase cDNA from Trichoderma harzianum. Some transformants contained an acid phosphatase signal peptide coding sequence from white lupin preceding the mature endochitnase gene. Here we show the expression of endochitinase in leaf and root tissues of transformed alfalafa, but not in control plants. Transgenic alfalfa also showed significantly increased chitinase enzyme activities, whereas little chitinase activity was observed in leaf and root extracts of control plants. Western blot and enzyme activity assay demonstrated the presence of the endochitinase protein in root exudates of transgenic plants but not in control plants. Results show that the fungal protein is secreted and a signal peptide from a heterologous plant species can direct the exudation of a foreign protein in alfalfa.