Positional Cloning And Preliminary Regulation Analysis Of The Short Growth Period Gene SGP(t)in Rice

Basing on previous study, we structure a large F2population using the parents sgp(i) and93-11, for the purpose of map-based cloning of the Short Growth Period gene SGP(t) in rice. At last we could successfully map the SGP(t) between the molecular markers Inde10651and Inde106122, which locate on the BAC clone AP004989.3. The two markers covered a physical distance of21kb. Sequence analysis of the candidate region indicated that one zinc finger protein-like gene is likely the candidate gene of SGP(t).Gene expression analysis of the leaves from wild type Minghui86and mutation sgp(t) at different development stage under short day indicated that sgp(t) gene controlled the expression of other florigen gene except Hd3a and RFT1, it can up-regulate these genes and their downstream gene OsMADS14, which promoted the transition from the vegetative to reproductive development. There is another possibility that sgp(t) gene might also avoid Hd3a gene, and control the expression of OsMADS14directly so as to regulate flowering. Therefore, sgp(t) is a key gene controlling rice flowering.