玉米细菌性条斑病非寄主抗性基因Rxo1转化水稻的研究

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

摘要:

水稻细菌性条斑病是我国重要的水稻病害之一，但是在水稻种质资源中尚未发现抗细菌性条斑病单个主效基因。利用农杆菌介导的转化系统将从玉米中克隆的细菌性条斑病非寄主抗性基因Rxo1转入我国2个杂交稻恢复系和2个常规水稻品种。转基因植株的PCR和Southern分析结果表明Rxo1基因已整合到受体基因组中，Rxo1基因单拷贝整合的转化体在自交T1代呈现抗感3∶1分离。人工接种实验和病菌的生长曲线表明携带Rxo1的转基因植株对水稻细条病菌可以产生过敏性抗病反应。上述结果为利用非寄主抗性基因防治该病害提供了有用的信息。

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.