水稻类病变突变体lrd40的抗病性与细胞学分析

 由中花11经γ射线诱变获得的水稻类病变突变体lrd40，是一个对环境不敏感的全生育期表达的突变体。遗传分析表明，lrd40的类病变性状为1个隐性位点控制，与已报道的类病变突变体lrd38、lrd39、lrd42是非等位的。经多点接种试验，lrd40对水稻白叶枯病2个菌系PXO99A和DY89031都表现抗病。lrd40与野生型杂交F2接种结果证实，lrd40的抗白叶枯病与类病变的表现是一致的。锥虫蓝（trypan blue）染色观察到lrd40的类病变发生可能是一个程序性细胞死亡过程，经二氨基联苯胺（diamino benzidine，DAB）染色检测到lrd40的类病变表达时，叶片上产生H2O2沉淀。细胞学观察结果说明，lrd40的类病变发生类似于植物防卫反应的早期特征，如细胞死亡和过敏反应导致的氧迸发（oxidative burst）。

Disease Resistance and Cytological Analyses on Lesion Resembling Disease Mutant lrd40 in Oryza sativa

Lesion resembling disease mutant lrd40, obtained from gamma ray mutagenesis of a japonica rice variety Zhonghua 11, expressed whole life lesion mimic in different environments. Genetic analysis showed that this mutant is controlled by a single recessive locus nonallelic to the loci of lrd38, lrd39 and lrd42. Repeated inoculation with Xanthomonas oryzae pv. oryzae (Xoo) showed that lrd40 conferred non race specific resistance to Xoo, and resistance to Xoo was associated with the lesion expression of lrd40 in the F 2 generations tested, indicating that disease resistance is controlled by the lrd40 locus. Trypan blue and DAB staining methods were used to detect programmed like cell death and deposition of H 2 O 2 during lesion development, all these observations resemble the early events of plant defense responses, including cell death and oxidative burst during the hypersensitive response.