Function Studies Of Zebra Mutant Oszb In Rice (Oryza Sativa L.)induced By Root Injury

The zebra leaves mutant in rice showed green and yellow zebra symptom on the young leaves and leaf sheaths only under the injury root and intense light conditions.the zebra leaf traits contrlled by a recessive gene,is excellent genetic marker for TGMS rice Lines and has important applications in hybrid rice seed production and seed identification.In this study,the recombinant inbred lines of zebra leaf rice mutant Oszb and R374 hybrids were taken as materials.The zebra leaf gene was cloned by using the method of whole-genome resequencing;we constructed Oszb-RNAi interference vector using the zebra leaf candidate genes,and transformed into japonica var nipponbare;We constructed Oszb complementary vector and transformed the rice zebra leaf mutant.The main results are as follows:1.By molecular markers(SNP and RAD)technology we get the location of zebra-leaf gene in rice.The results showed that 3942 separations of SNP were founded on Chromosome 1,2,3,4,6,11 and12.The Oszb gene was initially identified between 8820367-15181369 bp on the Chromosome 12 in rice.Combined with the reported gene function of rice,Oszb was taken as candidate gene for the following research.2.we used an RNA interference(RNAi)strategy to silence the Oszb gene and address the funtion of Oszb.The Oszb transcript level inthe RNAi transgenic lines were determined by RT-PCR and found the expression of the Oszb was severely suppressed.The RNAi transgenic plants also showed green and yellow zebra symptom on the young leaves and leaf sheaths only under the injury root and high-light conditions.This result showed that Oszb may be related with zebra symptom in rice.3.we constructed complement transgenic plants for Oszb gene.No difference was found between the complement transgenic plants and control plants(Japonica plants)under the injury root and high-light conditions.4.The RNAi transgenic plants showed significantly increased tillers,increased biomass,shorter intermodal distance and more sterile seeds than control plants(Japonica rice)under cold stress for a long period of time.Together,our results showed that Oszb gene may be related with leaf color trait and participates in cold stress signal pathways.