Rodríguez-Decuadro Susana, Silva Paula, Bentancur Oscar, Gamba Fernanda, Pritsch Clara
Phytopathology. 2014 Jul;104(7):715-23. doi: 10.1094/PHYTO-05-13-0133-R.
Much effort is being made to breed barley with durable resistance to leaf spot blotch incited by Bipolaris sorokiniana (teleomorph: Cochliobolus sativus). We hypothesized that susceptibility and resistance traits in 11 diverse barley genotypes inoculated with a single C. sativus isolate might specify a range of distinct host cell responses. Quantitative descriptions of interaction microphenotypes exhibited by different barley genotype seedlings after infection with C. sativus are provided. Early oxidative responses occurring in epidermis and mesophyll leaf tissue were monitored by histochemical analysis of H2O2 accumulation at 8, 24, and 48 h after inoculation. Cell wall apposition (CWA) in epidermal cells and hypersensitive reaction (HR) of epidermal or mesophyll tissue were early defenses in both resistant and susceptible genotypes. There were differences in level, duration, and frequency of occurrence for CWA and HR for the different barley genotypes. Occurrence of HR in epidermal cells at post-penetration stages was indicative of compatibility. Patterns of cell responses were microphenotypically diverse between different resistant and susceptible genotypes. This suggests that timing and level of response are key features of microphenotypic diversity that distinguish different functional mechanisms of resistance and susceptibility present in barley.
人们正在付出巨大努力来培育对由索氏平脐蠕孢（有性型：禾旋孢腔菌）引起的叶斑病具有持久抗性的大麦品种。我们假设，用单一的禾旋孢腔菌分离株接种11种不同大麦基因型后，其感病性和抗性特征可能会表现出一系列不同的宿主细胞反应。本文提供了不同大麦基因型幼苗在被禾旋孢腔菌感染后相互作用微表型的定量描述。通过对接种后8、24和48小时H2O2积累的组织化学分析，监测了表皮和叶肉组织中发生的早期氧化反应。表皮细胞中的细胞壁附着（CWA）以及表皮或叶肉组织中的过敏反应（HR）是抗性和感病基因型的早期防御反应。不同大麦基因型的CWA和HR在水平、持续时间和发生频率上存在差异。穿透后阶段表皮细胞中HR的出现表明具有亲和性。不同抗性和感病基因型之间细胞反应模式在微表型上存在差异。这表明反应的时间和水平是微表型多样性的关键特征，它们区分了大麦中存在的抗性和感病性的不同功能机制。
