Licorice Hmgr, Sqs1 And Beta As Gene Cnvs System Construction

Glycyrrhiza uralensis Fisch is commonly used in China, it has many functions, such as detoxification, relieving pain, clearing heat and so on. Furthermore, G. uralensis can be used as food taste, masking agent and tobacco additives. In recent years, reports have shown the revealing of the molecular mechanism of biosynthetic pathway of glycyrrhizin is very important. As a widely used Chinese herb, the requirement of G. uralensis is very great in China and other countries. As the key active component of G. uralensis, Glycyrrhizin is very effective in the treatment of inflammatory, aging, hypertension, and so on. Recent irresponsible overcollection of wild G. uralensis plants has resulted in the decrease and extinction of wild G. uralensis resources. In2000, the Chinese government imposed restrictions on the collection of wild G. uralensis plants. As a result, cultivar became the main resource of this herb. However, the degradation of quality and low content of glycyrrhizic acid are widely present in the cultivar of G. uralensis. So improving the quality of cultivar of G. uralensis has become the key problem of their sustainable development. Therefore it would be important and interesting to increase accumulation of glycyrrhizic acid in licorice plants by genetic engineering. And one effective means toward achieving this goal has been to study and modify the triterpene biosynthesis pathway leading to the formation of glycyrrhizic acid.CNVs, a new type of genomic variation that has recently received considerable attention, are deletions, insertions, duplications, and more complex veriations ranging from1kb to submicrioscopic sizes. It has many characteristics, such as wide distribution, hereditability, relative stability and high heterogeneity. CNVs can lead to the change of gene dosage and finally result in the change of phenotype character, and up to now many reports have shown that there are close relationship between CNVs and human diseases. However researches on CNVs in plants are very infrequent.Currently, the transgenic technology has been used to achieve the copy number variation of functional genes in plant. Different recombinant P. pastoris containing different copy numbers of functional genes HMGR, SQS1and β-AS have been constructed in our laboratory. The copy number of function genes in different recombinant P. pastoris has been detected. And it has provided a basis for over-expressing functional genes in G. uralensis and for increasing the accumulation of glycyrrhizic acid in cultivar of G. uralensis. For transgenic technology, as materials plants have their advantages. They can be used not only as bioreactors to produce proteins and important metabolites, but also to study the function of genes in metabolic pathway in plants. Therefore, in this study, agrobacterium-mediated method was used to transform exogenous genes into cells of G. uralensis. And we hope this work may provide a basis for revealing the influences of copy number variations on the accumulation of glycyrrhizic acid in cultivar of G. uralensis.The main results of this paper are as follows:1The plant expression vectors containing HMGR, SQS1and β-AS gene from G. uralensis were constructed and transformed into agrobacterium EHA105.2The rapid propagation of G. uralensis was constructed.3The recombinant EHA105containing HMGR, SQS1and β-AS gene from G. uralensis were transformed into hypocotyls and cotyledonary node of G. uralensis, and transgenic callus were obtained.