ABSTRACT
Nowadays, the water resources required for irrigation have declined and intensify the problem of water scarcity. Crop plants are mainly affected due to water scarcity. Water deficit may result in drought stress and thereby affect a plant’s water status. Drought stress is a major environmental issue that reduces the relative water content in crop plants and thereby decreases plant growth and yield. Hence, it is necessary to provide plants with some nutrients that can sustain water status in drought-stressed plants. Silicon is considered one of the salient elements that show hope, particularly under abiotic stress conditions such as drought stress. Fertilization with silicon has shown a positive role in the improvement of the growth and productivity of plants, particularly those belonging to the family Poacea. Numerous positive potential effects of silicon (Si) on plant growth and development have been documented, particularly under water deficit conditions. There are several strategies showing that silicon improves plant drought tolerance, through formation of a mechanical barrier, as Si is deposited on cell walls, lumens, and intercellular spaces, as well as xylem vessels. In addition, silicon modulates plant metabolism and alters physiological activities, thus enhancing drought stress tolerance. Likewise, a variety of genes are overexpressed by silicon in many drought-stressed plants. The products of these genes participate in the regulation of some
15.1 Introduction ..........................................................................................................................266 15.2 Silicon Fertilizer ...................................................................................................................266 15.3 Silicon in Plants .................................................................................................................... 267 15.4 Si-Mediated Drought Stress Tolerance .................................................................................268
