ABSTRACT
Rice bacterial leaf streak,caused by Xanthomonas oryzae pv. oryzicola is a destructive bacterial disease in China. Single-gene resistance to X. oryzae pv. oryzicola has not been found in rice germplasm. A cloned non-host gene from maize with resistance to bacterial leaf streak, Rxo1, was transferred into four Chinese rice varieties through an Agrobacterium-mediated system, including Zhonghua11, 9804, C418 and Minghui86. PCR and Southern analysis of the transgenic plants revealed the integration of the Rxo1 gene into the rice genomes. The integrated Rxo1 was stably inherited, and segregated in a 3:1 (Resistance:Susceptible) ratio in the selfed T1 generations derived from some T0 plants, indicating that Rxo1 inherited as a dominate gene in rice. Transgenic T0 plants and PCR-positive T1 plants were resistant to X. oryzae pv. oryzicola on the basis of artificial inoculation.
Subject(s)
Bacterial Proteins , Genetics , Metabolism , Genes, Plant , Genetics , Oryza , Genetics , Plant Diseases , Genetics , Microbiology , Plants, Genetically Modified , Genetics , Rhizobium , Genetics , Transformation, Genetic , Xanthomonas , Genetics , Zea mays , Genetics , MicrobiologyABSTRACT
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.