Vaculík Marek, Lukačová Zuzana, Bokor Boris, Martinka Michal, Tripathi Durgesh Kumar, Lux Alexander
Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Ilkovicova 6, Bratislava, Slovakia.
Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava, Slovakia.
J Exp Bot. 2020 Dec 2;71(21):6744-6757. doi: 10.1093/jxb/eraa288.
Silicon (Si), although not considered as an essential element for plants in general, can ameliorate the phytotoxicity induced by excess metal(loid)s whether non-essential (e.g. Cd, Pb, Cr, Al, As, and Sb) or essential (e.g. Cu, Ni, and Zn). The Si-enhanced resistance allowing plants to cope with this type of abiotic stress has been developed at multiple levels in plants. Restriction of root uptake and immobilization of metal(loid)s in the rhizosphere by Si is probably one of the first defence mechanism. Further, retention of elements in the root apoplasm might enhance the resistance and vigour of plants. At the cellular level, the formation of insoluble complexes between Si and metal(loid)s and their storage within cell walls help plants to decrease available element concentration and restrict symplasmic uptake. Moreover, Si influences the oxidative status of plants by modifying the activity of various antioxidants, improves membrane stability, and acts on gene expression, although its exact role in these processes is still not well understood. This review focuses on all currently known plant-based mechanisms related to Si supply and involved in amelioration of stress caused by excess metal(loid)s.
硅（Si）虽然通常不被视为植物的必需元素，但它可以减轻由过量金属（类金属）引起的植物毒性，无论这些金属（类金属）是非必需的（如镉、铅、铬、铝、砷和锑）还是必需的（如铜、镍和锌）。植物通过多种层面形成了硅增强抗性以应对这类非生物胁迫的机制。硅对根际中金属（类金属）的吸收限制和固定作用可能是首要防御机制之一。此外，元素在根质外体中的留存可能会增强植物的抗性和活力。在细胞水平上，硅与金属（类金属）之间形成不溶性复合物并将其储存在细胞壁内，有助于植物降低可利用元素的浓度并限制共质体吸收。此外，硅通过改变各种抗氧化剂的活性来影响植物的氧化状态，提高膜稳定性，并作用于基因表达，尽管其在这些过程中的确切作用仍未完全清楚。本综述聚焦于目前所有已知的与硅供应相关且参与减轻过量金属（类金属）胁迫的植物机制。
