Ecotopic Expression Analysis Of Three FT Homologues From Poncirus Trifoliata (L.) Raf.

Higher plants need to go through a period of time of vegetative growth after germination, namely juvenile period, and then go into reproductive stage. The development mechanism of juvenile period has been a high-profile issue in woody plant breeding, especially for some forests have economic value, and fruit trees for the purpose of harvest. Late 70,20th century, an early flowering mutant of precocious trifoliate orange, Poncirus trifoliata (L.) Raf, was discovered in China. The mutant flowering 1-2 years later after sowing, and different with wild type trifoliate orange, the mutant can flowering times within a year. Several FT-like genes, with different lengths, were isolated from the mutant in our laboratory. In this study, tobacco and strawberry were used as experimental materials, GM (gene transform) has been used to study genes function. The main results are as follows:l.We got 42 Gm 35s:PtFT1 plants via agrobacterium-mediated transformation. PtFTl is the full length cDNA of PtFT and general uesed in Gm.In the Gm plants of Arabidopsis thaliana and Citrus, researchers obtained ideal experimental results flowering earlier.In my research,the Gm 35s:PtFT1 plants just flowering ten days earlier than wild type, which means that PtFTl can promote Nicotiana tabacum flowering earlier, but the phenotype is not clear.2.We got 11 Gm 35s:PtFT2 plants via agrobacterium-mediated transformation. PtFT2 is the full length DNA of PtFT deleted the first intron.There is a redundant sequence in PtFT2 while its function is unknown so far.The Gm 35s:PtFT2 plants showed a outstanding earlier flowering phenotype under LD with a 100 days shorten。However, this result is not same as it repoted. Abviously, PTFT2 has the function to promote flowering,beside, the redundant sequence may up-regulate PtFT expression.3.We got 20 Gm 35s:PtFT3 plants via agrobacterium-mediated transformation. PtFT2 with the redundant sequence deleted come to be PtFT3. The Gm 35s:PtFT3 plants had a same flwering time as 35s:PtFT1.Which means that PTFT3 has a function as promting flowering and also shows that the redundant sequence indeed has a important regulation on floweing time.