Cloning Of Zr1 Gene From Zizania Latifolia (griseb.) And Evaluation Of Zr1-transgenic Rice To Bacterial Blight

Rice is one of the most important food crops in the world, and it is also staple food of more than fifty percent population in China. Insect pest which influences the output of rice is a serious problem in provisionment. Heriditary basis that plant evolution endowed with every crop is limit, which make rice breeding with high-resistance, high-yield and high-quality linger. Deficiency of gene resources had became to limitation and bottle-neck in rice-breeding. We should expand gene banks in order to break through in crop breeding improvement, so the best way is to transfer excellent genes of heterology plants to crops including rice.Zizania lattfolia (Griseb.) is included in the Oryza tribe and possesses numerpus traits valuable for rice breeding, such as disease and insect resistance, cold and flood tolerance, and high grain quality. The genetic and breeding of Zizania lattfolia are still in their infancy.Studies on plant resistant genes are one of the hotspots in the field of plant molecular biology. Until now, among the over 50 separated resistant genes, The conservation and similarity of plant disease resistance(R) genes in major structural domains perhaps provided a new approach to utilize their homologous sequences to clone unknown resistance genes. Based on the sequence of resistance gene analog FZ14 derived from Zizania latifolia(Griseb.), a pair of specific PCR primers FZ14P1/FZ14P2 was designed to isolate candidate disease resistance gene. The pooled-PCR approach was adapted using the primer pairs to screen a genomic TAC (Transformation-competent artificial chromosome) library derived from Zizania latifolia. A positive TAC clone (ZR1) was obtained and confirmed by sequence analysis. The results indicated that ZR1 consisted of conserved motifs similar to P-loop (kinase 1a), kinase 2, kinase 3a and GSPL, indicating it could be a portion of NBS-LRR type of resistance gene. Using A. tumafaciens-mediated transformation of Nippobare mature embryo, a total of 48 independent transgenic T0 plants were obtained. Among them, 36 plants were highly resistant to the virulent bacterial strain PXO71. The results indicated that ZR1 contains at least one bacterial blight resistance gene. Characterization of the full length candidate gene and genetic analysis of transgenic progenies are currently underway.