Introduction of a Non-host Gene Rxo1 Cloned from Maize Resistant to Rice Bacterial Leaf Streak into Rice Varieties

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.