Molecular Basis of Structural Studies, Phytochemical Characterization and Nutritional Evaluation of New Modified Alfalfa (with "HB", "TT8" and "miR156" Genes) Developed through Gene Transformation and Gene Modification in Ruminant Livestock Systems

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Alfalfa (Medicago sativa L.) is one of the most important forages in the world. Its nutritional quality can be improved through three approaches: (1) Gene-transformation and/or gene modification to make alfalfa produce an optimal level of proanthocynidins; (2) Modification of lignin conformation through changing biosynthesis pathway in complex cell wall to reduce lignin impact on nutrient availability; and (3) Modification of phenylpropanoid biosynthetic pathway to reduce hydroxycinnamic acid compounds in complex cell wall of alfalfa.*Recently, three newly developed gene-modified alfalfa genotypes ("HB", "TT8" and "miR156" genes) have became available. It is expected that these genes may result in producing proanthocynidins, affect lignin and hydroxycinnamic acid biosynthesis pathway and reduce lignin and hydroxycinnamic acid levels, and modify lignin conformation in complex cell wall. This should, in turn, benefit the degree of change in rumen degradation kinetics, allow for an optimized nutrient degradation ratio, improve nutrient availability and result in the reduction and prevention of bloat and other digestive disorders.*The objective of this program is to attain a comprehensive understanding of the new "HB", "TT8" and "miR156"gene transformation and gene modification that influence alfalfa's intrinsic structure on a molecular basis as well as nitrogen metabolism, microbial nitrogen accumulation, rumen microbial activity, and the efficiency of nitrogen utilization in complex ruminant systems. This project will provide important information to assist the development of super genotypes of alfalfa. A series of experiments combining advanced molecular biotechnology, synchrotron molecular techniques as well as in vitro, in vivo and modeling experimental approaches will be conducted to address the stated hypothesis and objectives. The training of Highly Qualified Personnel  (HQP) will take place through this proposal. This research program has been designed to be suitable for the training of both M.Sc. and Ph.D. students.*The proposed research will contribute significantly to our knowledge in a comprehensive understanding of the gene transformation and modification that influence alfalfa's intrinsic molecular structure, molecular structure and nutrient utilization interaction in complex rumen system. In the long-term, it is estimated (in a report by Agriculture and Agri-Food Canada) that a $2-4B annual cost savings will be realized for the $8-12B Canadian dairy and beef cattle industry through the development of final super genotypes of alfalfa.******