Initial Studying Of Function For Rice Blast Gene-Pib ORF Region By Rice Transformation

The Pib gene is the first major resistant rice blast gene that was cloned by map-based clone technique. This Pib gene was isolated from rice genome, its sequence of DNA kept the original state. It is a good material for studying the correlation of the structure function of resistance gene in the molecular level.First, the sequence of Pib was analyzed using DNAman.Second, five plant binary expression vectors pNAR501, pNAR502 and pNAR503 et al driven by CaMV35S constitute promoter were constructed respectively according to the structure characteristics of open reading frame of Pib gene. Exon2-exon3 fragment of Pib gene was constructed into pNAR501. 5' partial deletion exonl fragment of Pib was constructed into pNAR502. 5' partial deletion exonl- exon2-exon3 fragment of Pib was constructed into pNAR503 et al.Third, the vectors were transformed into calli from mature embryos of Nipponbare by Agrobacterium mediated transformation, and 30 independent transgenic plants were obtained.Forth, transgenic plants were analyzed by PCR, Southern and Hyt resistance.Last, T₀ and T₁ transgenic plants were inoculated rice blast pathogen.Rice blast resistance test in vitro for T₀ transgenic plants to test their blast resistance showed higher blast resistance than that of control Nipponbare and transgenic plants of pNAR501 were highest resistance in three constructions which was class 2 to El, F1 and G1 races. But the results of rice blast resistance test for T₁ transgenic plants in 3-4 leaves stage showed different: all of the transgenic progeny were worse than that of control and all were class 8 to E1, F1, G1 races of rice blast while resistance of control Nipponbare was only class 7.