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

紫花苜蓿(Medicago sativa L.)是世界上最重要的牧草之一。通过三种途径改善紫花苜蓿的营养品质：(1)通过基因转化和/或基因修饰使紫花苜蓿产生最佳水平的原花青素；(2)通过改变复合细胞壁的生物合成途径来改变木质素的构象，以减少木质素对营养物质利用率的影响；(3)通过改变苯丙烷生物合成途径来减少紫花苜蓿复合细胞壁中的羟基肉桂酸化合物。 最近，三个新开发的转基因紫花苜蓿基因型(HB、TT8和miR156基因)已经问世。预计这些基因可能导致产生原花青素，影响木质素和羟基肉桂酸的生物合成途径，降低木质素和羟基肉桂酸的水平，并改变复杂细胞壁中的木质素构象。这反过来应该有利于瘤胃降解动力学的变化程度，允许优化营养物质降解率，提高营养物质的利用率，并导致减少和预防腹胀和其他消化疾病。 本项目的目标是全面了解新的“HB”、“TT8”和“miR156”基因转化和基因修饰在分子基础上对紫花苜蓿内在结构的影响，以及在复杂反刍动物系统中对氮代谢、微生物氮积累、瘤胃微生物活性和氮素利用效率的影响。该项目将为发展紫花苜蓿的超级基因类型提供重要的信息。将进行一系列实验，结合先进的分子生物技术、同步辐射分子技术以及体外、体内和模拟实验方法，以解决所述的假设和目标。高素质人才培训(HQP)将通过这项提议进行。这一研究计划旨在适合这两个硕士学位的培训。还有博士生。 这项研究将有助于我们全面了解影响紫花苜蓿在复杂瘤胃系统中的内在分子结构、分子结构和营养利用相互作用的基因转化和修饰。从长远来看，据估计(在加拿大农业和农业食品公司的一份报告中)，通过开发最终的超级紫花苜蓿基因型，每年将为价值80-120亿美元的加拿大奶牛业和肉牛业节省20-40亿美元的成本。

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.