Núcleo de Biotecnologia, Universidade Federal do Espírito Santo, Vitoria, ES 29040-090, Brazil.
Plant Cell Rep. 2010 Oct;29(10):1109-17. doi: 10.1007/s00299-010-0894-9. Epub 2010 Jul 6.
Fusariosis, caused by the fungus Fusarium subglutinans f. sp. ananas (Syn. F. guttiforme), is one of the main phytosanitary threats to pineapple (Ananas comosus var. comosus). Identification of plant cell responses to pathogens is important in understanding the plant-pathogen relationship and establishing strategies to improve and select resistant cultivars. Studies of the structural properties and phenolic content of cell walls in resistant (Vitoria) and susceptible (Perola) pineapple cultivars, related to resistance to the fungus, were performed. The non-chlorophyll base of physiologically mature leaves was inoculated with a conidia suspension. Analyses were performed post-inoculation by light, atomic force, scanning and transmission electron microscopy, and measurement of cell wall-bound phenolic compounds. Non-inoculated leaves were used as controls to define the constitutive tissue characteristics. Analyses indicated that morphological differences, such as cell wall thickness, cicatrization process and lignification, were related to resistance to the pathogen. Atomic force microscopy indicated a considerable difference in the mechanical properties of the resistant and susceptible cultivars, with more structural integrity, associated with higher levels of cell wall-bound phenolics, found in the resistant cultivar. p-Coumaric and ferulic acids were shown to be the major phenolics bound to the cell walls and were found in higher amounts in the resistant cultivar. Leaves of the resistant cultivar had reduced fungal penetration and a faster and more effective cicatrization response compared to the susceptible cultivar.
镰刀菌病由真菌串珠镰刀菌（Syn. F. guttiforme）引起，是菠萝（Ananas comosus var. comosus）的主要植物检疫威胁之一。鉴定植物细胞对病原体的反应对于理解植物-病原体关系和建立提高和选择抗性品种的策略非常重要。对与真菌抗性相关的抗（维多利亚）和敏感（佩罗拉）菠萝品种的细胞壁结构特性和酚类含量进行了研究。用分生孢子悬浮液接种生理成熟叶片的非叶绿素基部。接种后进行光镜、原子力显微镜、扫描和透射电子显微镜分析，以及细胞壁结合酚类化合物的测量。未接种的叶片用作对照，以定义组成组织特征。分析表明，细胞壁厚度、愈合过程和木质化等形态差异与对病原体的抗性有关。原子力显微镜表明，抗性和敏感品种的机械性能存在显著差异，抗性品种的结构完整性更高，与细胞壁结合的酚类化合物水平更高。鉴定出对香豆酸和阿魏酸是与细胞壁结合的主要酚类物质，在抗性品种中含量更高。与敏感品种相比，抗性品种的叶片真菌穿透减少，愈合反应更快、更有效。
