RESUMO
The dominant gene Xa21 with broad-spectrum and high resistance to Xanthomonas oryzae pv. oryzae (Xoo) was transferred into C418, an important restorer line of japonica hybrid rice in China using double right-border (DRB) T-DNA binary vector through Agrobacterium-mediated transformation. 17 transgenic lines were Xa21-positive with high resistance to the race P6 of Xoo through PCR analysis and resistance identification, among the total 27 independent primary transformants (T0) obtained. The subsequent analysis of the T1 progenies of these 17 T0 lines through PCR-assisted selection and resistance investigation showed that four Xa21 transgenic T0 lines could produce selectable marker-free (SMF) progenies. The frequency of primary transformants producing SMF progenies was 15%. In addition, PCR analysis also revealed these SMF progenies did not contain vector backbone sequence, and they were named as SMF and vector backbone sequence-free (SMF-VBSF) Xa21 transgenic plants. The further molecular and phenotypic analysis of the T2 and T3 progenies testified the homozygous SMF-VBSF Xa21 transgenic plants were obtained with high resistance to Xoo.
Assuntos
DNA Bacteriano , Genética , Vetores Genéticos , Oryza , Genética , Proteínas de Plantas , Genética , Plantas Geneticamente Modificadas , Genética , Proteínas Serina-Treonina Quinases , Genética , Rhizobium , Genética , Transformação Genética , XanthomonasRESUMO
The mutant population of Xanthomonas oryzae pv oryzae strain differential to rice bacterial blight resistance gene Xa23 has been constructed mediated by transposon in vivo . The results of PCR amplification with specific primers and analysis of flanking sequence of mutants indicated that the foreign DNA has been integrated into X. oryzae pv oryzae genome. Four mutants with changed avirulent activity to Xa23 gene have been identified by artificial inoculation. It is possible to clone genes that are required for AvrXa23 avirulence activity using this new strategy.
Assuntos
Proteínas de Bactérias , Genética , Sequência de Bases , Elementos de DNA Transponíveis , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dados de Sequência Molecular , Mutação , Oryza , Genética , Microbiologia , Doenças das Plantas , Microbiologia , Plantas Geneticamente Modificadas , Genética , Microbiologia , Virulência , Xanthomonas , Genética , Virulência , FisiologiaRESUMO
By using rice SSRP, RAPD and AFLP molecular markers, the genome of rice transgenic line "Minghui 63-Xa21" was analyzed. 32 SSRP primers, 42 RAPD primers and 8 AFLP primers could produce obvious PCR bands in the analysis of at least 12 individual plants selected randomly from "Minghui 63-Xa21" T3 generation. Totally 550 PCR bands, equivalent to 550 genomic sites, were detected. Different individual plants of the transgenic homozygous line displayed almost the same PCR pattern. Compared with the control "Minghui 63", no difference was found in their PCR patterns. This indicated that the introduction of Xa21 into the genome of "Minghui 63" did not change these 550 genome sites and their heredity. Very few variant PCR bands were observed in some individual plants from both "Minghui 63-Xa21" and "Minghui 63". However, the variant percentage was equivalent between the transgenic line and the non-transgenic control line.