Abstract: To explore the effect of two disease resistance-encoding genes with different mechanisms on resistance against Xanthomonas oryzae pv. oryzae (Xoo), Agrobacterium-mediated transformation was used to acquire plants expressing CecropinB, Xa21, and both the genes, respectively, and which were verified by PCR analysis. The single transgene showed moderate resistance to all of the Xoo strains tested, and the resistance level of Xa21 was stronger than that of CecropinB. With the co-expression of CecropinB and Xa21, the resistance was enhanced, indicating that gene pyramiding with different resistance mechanisms is a potential strategy in developing rice plants with durable resistance.

Key words: disease resistance gene, gene transfer, bacterial blight, co-expression, resistance, rice

摘要： 为了探明CecropinB与Xa21这两种不同抗病途径的基因单独或共表达后的田间抗白叶枯病表现，利用农杆菌转化技术，获得了这两个基因的单独和共表达后的植株。利用PCR等分子鉴定技术，证明这两个基因已经整合到水稻基因组中。抗病性检测结果表明，Xa21和CecropinB均能提高水稻对白叶枯病的抗性，且Xa21的抗病性较CecropinB明显。Xa21和CecropinB基因共表达后的植株的抗病性比单基因的更强，说明将不同抗性机制的基因共表达，可以在育种上利用以提高水稻的白叶枯病抗性。

关键词: 抗病基因, 转基因, 白叶枯病, 共表达, 抗性, 水稻