Phytopathology. 2002 Oct;92(10):1095-103. doi: 10.1094/PHYTO.2002.92.10.1095.
ABSTRACT Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by electron microscopy and X-ray microanalysis. A blast-susceptible cultivar, Jinmi, and a partially resistant cultivar, Hwaseong, were grown under a hydroponic culture system with modified Yoshida's nutrient solution containing 0, 50, 100, and 200 ppm of silicon. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamellae, and intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface, with relatively small deposition on stomatal guard cells in silicon-treated plants. Silicon accumulation and epidermal cell wall thickness in leaves were greater in cv. Jinmi than in cv. Hwaseong. However, the thickness ratios of the silicon layers to epidermal cell walls were greater in cv. Hwaseong (53.25 to 93.28%) than in cv. Jinmi (36.58 to 66.54%). Leaf blast severity was lower in cv. Hwaseong than in cv. Jinmi and was significantly reduced in silicon-treated plants of both cultivars. These results suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.
摘要 本研究通过电子显微镜和 X 射线微分析研究了硅在水稻叶片中的积累位置及其与稻瘟病抗性的可能关联。以易感病品种 Jinmi 和部分抗性品种 Hwaseong 为材料，在含有 0、50、100 和 200 ppm 硅的改良 Yoshida 营养液水培系统中进行培养。在硅处理植株的表皮细胞壁的角质层下，经常发现电子致密的硅层。在外层区域检测到更多的硅。硅主要存在于表皮细胞壁、中层和表皮组织的细胞间隙中。此外，硅在叶片表面普遍存在，而在硅处理植株的气孔保卫细胞中沉积较少。硅在 Jinmi 品种叶片中的积累和表皮细胞壁厚度大于 Hwaseong 品种。然而，Hwaseong 品种（53.25 至 93.28%）的硅层与表皮细胞壁的厚度比大于 Jinmi 品种（36.58 至 66.54%）。Hwaseong 品种的叶片稻瘟病严重程度低于 Jinmi 品种，且在两个品种的硅处理植株中均显著降低。这些结果表明，硅诱导的水稻叶片细胞壁强化可能与增强对稻瘟病的宿主抗性密切相关。
