Overexpression And RNAi Of BpFLC In Betula Platyphylla

FLC is a critical gene of regulating flowering process in plants, which is a repressor of flowering, especially in vernalization pathway. The FLC in Betula platyphylla, named as BpFLC, was studied. We analyzed the influence of BpFLC on vegetative growth and reproductive growth of birch. RNAi of BpFLC was performed in birch using method of genetic transformation. Finally we analyzed the expression of BpFLC by Q-PCR.By Q-PCR, We measured the expression profile of BpFLC of different growth phase in birch, we found that the expression of BpFLC in5-year-old and older more birch was low. We also measured the expression of BpFLC in birch of5years old in different month, and found that the expression of BpFLC in May and Jule is lowest. Moreover, we measure the Height of wild-type birch and BpFLC-transgenic birch of4,6and8months, respectively. We find that there is significant difference between number6,8,10transgenic lines and wild type. And along with the growth of birch, the height difference between L6, L8of transgenic lines and wild-type becomes more significant. We measured the ground diameter of wild type birch and BpFLC-transgenic birch of9months old, and fond that there is significant difference between transgenic lines L4, L9, L10and wild type. Especially L10is extremely significant. It illustrates that BpFLC gene has certain influence on height and ground diameter of birch. The statistical growth status of the transgenic birch and wild type birch after dormancy suggest that there is nearly no difference between transgenic birch and wild type. We guess that BpFLC gene has little influence upon the growth status of birch after dormancy, but L4, L8, L10and LI1more easily grew new branches from base than wild type, especially number4and11.In order to generate more plantlets, we reproduces and cultivate BpFLC-transgenic birch, from short stem to callus, and to cluster seedling, to rooting seedling, and finally transplant to soil in flowerpot. This process needs5to6months. Now, we have got550to600trees for later experimental forestation.We get FLC-RNAi interference vectors and by Liquid nitrogen freezing and thawing method. We introduced the vectors into Agrobacterium Tumefaciens EHA105strains and transformed into Betula platyphylla. We have got5transgenic lines. By Q-PCR, we found that the BpFLC expression level of BpFLC-RNAi-transgenic birch was reduced.