Establishing A High-Efficient Tissue Culture System And Exploring Gene Transformation In Mulberry

As an important economic tree species in China, mulberry Morus L. is a perennial woody plant with twin cotyledon and its' leaf is the main natural forage for silkworm Bombyx mori L.. Therefore the main purpose of Mulberry cultivation is leaf production and the sustainable development of silk industry will rely on mulberry as its' material base. In addition, the medicinal value of mulberry also has being the hot research spots recently.The research of mulberry gene transformation was started relatively late, but it is already known that mulberry is sensitive to Agrobaterium. Using Agrobaterium tumefeciens-mediated method and gene gun method, the foreign gene was transferred into mulberry and the gene expression is successful. So far, most of the foreign genes transferred into mulberry are resistance ones, such as Cecropin gene and Oryzacystatin gene, and it is short of the research on transformation of other valuable gene, especially the genes with special properties or high economic value. Meanwhile, there are many problems in mulberry gene transformation, such as the difficult to establishing regeneration system, high reliability on gene type, low transformation efficiency. Based on the work of predecessors, this study established the new complete genetic transformation system using Agrobaterium tumefedens-mediated method, through the establishment of mulberry high frequency regenerative system and the optimization of genetic transformation factors. And by applying this genetic transformation system, the auxin influx carrier gene of Populus tomentosa PtAUX1 was transferred into mulberry successfully in the hope to improve its economic properties. The main results are the following:1. Using the bioinformatics software and database, analyzed the bioinformatics of the auxin influx carrier gene PtA UX1 and its encoded protein of Populus tomentosa, which was cloned previously. The result shown that the total length of the encoded area of PtAUXl mature peptide is 1 760 bp. This sequence included an open reading frame with the length of 1 431 bp, encoding 477 amino acid; PtAUX1 located on the cell membrane, there are totally 9 trans-membrane areas; in its second level structure, there include abundant alpha helix and...