Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, 38000, Faisalabad, Pakistan.
Department of Environmental Sciences, University of Gujrat, Hafiz Hayat Campus, Jalal Put Jattan Road, Gujrat, Pakistan.
Environ Sci Pollut Res Int. 2015 Oct;22(20):15416-31. doi: 10.1007/s11356-015-5305-x. Epub 2015 Sep 3.
Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na(+) uptake and translocation while increased K(+) uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.
干旱和盐度是限制全球作物产量和质量的主要非生物胁迫因素。提高干旱和盐渍地区的粮食产量是满足未来粮食需求增长的关键。据广泛报道，硅（Si）是土壤中第二丰富的元素，可减少植物的干旱和盐胁迫。在这里，我们回顾了 Si 增强植物抗旱和耐盐性的作用，并强调了 Si 缓解植物干旱和盐胁迫的机制。在干旱或盐胁迫下，硅的应用均增加了植物的生长、生物量、光合色素、秸秆和籽粒产量以及品质。在盐胁迫和干旱胁迫下，主要的诱发机制是营养元素的动态平衡、气体交换特性的改变、渗透调节、调节相容性溶质的合成、抗氧化酶的刺激以及基因表达。此外，硅的应用降低了钠（Na+）的吸收和转运，而增加了钾（K+）的吸收和转运。然而，这些机制因植物种类、基因型、生长条件、胁迫持续时间等而有所不同。本文综述了通过硅应用提高植物抗旱和耐盐性的潜力，为硅在盐渍土壤和世界干旱半干旱地区的应用提供了理论基础。本文还强调了未来关于硅在干旱胁迫下和盐渍土壤中的作用的研究需求。
