title: Mechanisms of silicon-mediated alleviation of abiotic stresses in higher plants: a review.
abstract: Although silicon (Si) is the second most abundant element both on the surface of the Earth's crust and in soils, it has not yet been listed among the essential elements for higher plants. However, the beneficial role of Si in stimulating the growth and development of many plant species has been generally recognized. Silicon is known to effectively mitigate various abiotic stresses such as manganese, aluminum and heavy metal toxicities, and salinity, drought, chilling and freezing stresses. However, mechanisms of Si-mediated alleviation of abiotic stresses remain poorly understood. The key mechanisms of Si-mediated alleviation of abiotic stresses in higher plants include: (1) stimulation of antioxidant systems in plants, (2) complexation or co-precipitation of toxic metal ions with Si, (3) immobilization of toxic metal ions in growth media, (4) uptake processes, and (5) compartmentation of metal ions within plants. Future research needs for Si-mediated alleviation of abiotic stresses are also discussed.
authors.affiliation: Ministry of Agriculture Key Laboratory of Plant Nutrition and Nutrient Cycling, Institute of Soil and Fertilizer, Chinese Academy of Agricultural Sciences, Beijing, China. ycliang@caas.ac.cn
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Liang
authors.forename: Wanchun
authors.initials: W
authors.lastname: Sun
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
authors.forename: Peter
authors.initials: P
authors.lastname: Christie
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001692:Biological Transport / Q000502:physiology; D011232:Chemical Precipitation; D007477:Ions / Q000737:chemistry / Q000633:toxicity; D019216:Metals, Heavy / Q000737:chemistry / Q000633:toxicity*; D008954:Models, Biological; D018384:Oxidative Stress / Q000502:physiology; D010944:Plants / Q000378:metabolism*; D012825:Silicon / Q000378:metabolism*; D012965:Sodium Chloride / Q000737:chemistry / Q000633:toxicity; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D007477:Ions; D019216:Metals, Heavy; D012989:Soil Pollutants; D012965:Sodium Chloride; D012825:Silicon