Ahammed Golam Jalal, Yang Youxin
College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, 471023, Henan, China.
Jiangxi Key Laboratory for Postharvest Technology and Nondestructive Testing of Fruits & Vegetables, Collaborative Innovation Center of Post-Harvest Key Technology and Quality Safety of Fruits and Vegetables, College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045, China.
Plant Physiol Biochem. 2021 Aug;165:200-206. doi: 10.1016/j.plaphy.2021.05.031. Epub 2021 May 24.
Silicon (Si) acts as a beneficial element for plant growth and provides protection against abiotic and biotic stresses. Despite numerous reports on the beneficial role of Si in enhancing plant resistance to fungal pathogens, the underlying mechanisms remain largely unclear. Silicon shows antifungal activity; however, Si-induced improved disease resistance is partly manifested by the formation of Si polymerized mechanical obstruction under the cuticle and in cell walls, which prevents fungal ingress. Moreover, rapid production of defense compounds through secondary metabolic pathways is thought to be a key mechanism of Si-induced chemical defense against fungal pathogens beyond the physical barrier. Besides, improved mineral nutrition assures the healthy status of Si-supplied plants and a healthy plant exhibits better photosynthetic potential, antioxidant capacity and disease resistance. Multiple plant hormones and their crosstalk mediate the Si-induced basal as well as induced resistance; nonetheless, how root uptake of Si systemically modulates resistance to foliar diseases in low Si accumulating plants, needs in-depth investigation. Recent studies also indicate that Si influences effector-triggered immunity by affecting host recognition and/or limiting receptor-effector interactions. Here we review the role of Si in plant response to fungal pathogens. We also discuss and propose potential mechanisms of Si-induced enhanced disease resistance in plants. Finally, we identify some limitations of research approaches in addressing the beneficial roles of Si in biotic stress management.
硅（Si）作为植物生长的有益元素，可提供对非生物和生物胁迫的保护。尽管有大量关于硅在增强植物对真菌病原体抗性方面有益作用的报道，但其潜在机制仍 largely 不清楚。硅具有抗真菌活性；然而，硅诱导的抗病性提高部分表现为在角质层下和细胞壁中形成硅聚合机械障碍，从而阻止真菌侵入。此外，通过次生代谢途径快速产生防御化合物被认为是硅诱导的针对真菌病原体的化学防御超越物理屏障的关键机制。此外，改善矿物质营养可确保供硅植物的健康状态，而健康的植物具有更好的光合潜力、抗氧化能力和抗病性。多种植物激素及其相互作用介导了硅诱导的基础抗性和诱导抗性；尽管如此，在低硅积累植物中，硅的根系吸收如何系统地调节对叶部病害的抗性，仍需要深入研究。最近的研究还表明，硅通过影响宿主识别和/或限制受体-效应子相互作用来影响效应子触发的免疫。在这里，我们综述了硅在植物对真菌病原体反应中的作用。我们还讨论并提出了硅诱导植物增强抗病性的潜在机制。最后，我们指出了在研究硅在生物胁迫管理中的有益作用时研究方法的一些局限性。
