Fine Mapping Of A Dominant Earliness Gene Ef-s In Rice And Some Research Of A Novel Transcription Factor MYB

In higher plant, flowering transition represents a crucial transition from a vegetative to reproductive phase of life cycle, which is controlled by both endogenous and environmental factors. In Arabidopsis, it has been shown that there are four pathways, photoperiod pathways, vernalization pathway, autonomous pathway, and GA pathway involved in flowering control. It also demonstrated that these flowering transition pathways are highly conserved in Arabidopsis and other higher plants including rice.We have isolated a dominant early-flower gene which named Ef-s from 6442s-7. And the NIL D459 with Ef-s transmited in was constructed using an early-maturing indica line 6442S-7 as donor, and late-maturing indica lines Shuhui 881 as recipients. In order to clone Ef-s, F2 segregation population was made by crossing D459 and 9308R. By linkage analysis with SSR markers, the Ef-s gene was firstly mapped in a 4 Mb region between RM6925 and RM5556 on chromosome 8. The Ef-s gene was further narrowed down in a 600Kb region. In this region, quite a number of candidate genes existed, and we are continuning figure out the candidate gene via new markers.Besides, in a large scale of salt tolerate mutant screening, a mutant with enhancing tolerant to salt was obtained. The candidate gene of the mutant is a novel transcription factor OSMCB2g which encode a BAB12698 protein. T-DNA insert in front of ATG 55bp. OSMCB2g probably participated in salt stress signal transduction pathway. Over-expression 2300-35S-OSMCB2g and prokaryotic expression vectors PET-28b-OSMCB2g were constructed. The over-expression vector 2300-35S-OSMCB2g was transformed into rice. The positive transgenic individuals of rice showed more tolerant to salt than wild rice. The prokaryotic expression vector PET-28b-OSMCB2g was transformed into host bacterium, BL21, and was induced to express by IPTG, the purpose protein were identified by SDS-PAGE. We also made poly-antibody through inject rat with PET-28b-OSMCB2g protein. And further studies are in proceeding.