Phytopathology. 2004 Feb;94(2):177-83. doi: 10.1094/PHYTO.2004.94.2.177.
ABSTRACT Although several reports underscore the importance of silicon (Si) in controlling Magnaporthe grisea on rice, no study has associated this beneficial effect with specific mechanisms of host defense responses against this fungal attack. In this study, however, we provide evidence that higher levels of momilactone phytoalexins were found in leaf extracts from plants inoculated with M. grisea and amended with silicon (Si(+)) than in leaf extracts from inoculated plants not amended with silicon (Si(-) ) or noninoculated Si(+) and Si(-) plants. On this basis, the more efficient stimulation of the terpenoid pathway in Si(+) plants and, consequently, the increase in the levels of momilactones appears to be a factor contributing to enhanced rice resistance to blast. This may explain the lower level of blast severity observed on leaves of Si(+) plants at 96 h after inoculation with M. grisea. The results of this study strongly suggest that Si plays an active role in the resistance of rice to blast rather than the formation of a physical barrier to penetration by M. grisea.
摘要 尽管有几项报告强调了硅（Si）在控制稻瘟病菌方面的重要性，但没有研究将这种有益效果与宿主防御反应的特定机制联系起来。然而，在这项研究中，我们提供了证据，表明与未用硅（Si(-)）处理或未接种 Si(+)和 Si(-)的植物相比，用硅（Si(+)）处理并接种稻瘟病菌的植物叶片提取物中的咪鲜胺植物抗毒素的含量更高。在此基础上，Si(+)植物中萜类途径的更有效刺激，以及咪鲜胺含量的增加，似乎是增强水稻对稻瘟病抗性的一个因素。这可以解释在接种稻瘟病菌 96 小时后，Si(+)植物叶片上稻瘟病严重程度较低的原因。这项研究的结果强烈表明，硅在水稻对稻瘟病的抗性中发挥着积极的作用，而不是形成一种物理屏障来阻止稻瘟病菌的穿透。
