Silicon Mitigates Negative Impacts of Drought and UV-B Radiation in Plants

Abstract

Due to climate change, plants are being more adversely affected by heatwaves, floods, droughts, and increased temperatures and UV radiation. This review focuses on enhanced UV-B radiation and drought, and mitigation of their adverse effects through silicon addition. Studies on UV-B stress and addition of silicon or silicon nanoparticles have been reported for crop plants including rice, wheat, and soybean. These have shown that addition of silicon to plants under UV-B radiation stress increases the contents of chlorophyll, soluble sugars, anthocyanins, flavonoids, and UV-absorbing and antioxidant compounds. Silicon also affects photosynthesis rate, proline content, metal toxicity, and lipid peroxidation. Drought is a stress factor that affects normal plant growth and development. It has been frequently reported that silicon can reduce stress caused by different abiotic factors, including drought. For example, under drought stress, silicon increases ascorbate peroxidase activity, total soluble sugars content, relative water content, and photosynthetic rate. Silicon also decreases peroxidase, catalase, and superoxide dismutase activities, and malondialdehyde content. The effects of silicon on drought and concurrently UV-B stressed plants has not yet been studied in detail, but initial studies show some stress mitigation by silicon.

Changes in the Physiological and Morphometric Characteristics and Biomass Distribution of Forage Grasses Growing under Conditions of Drought and Silicon Application

“…The elevated levels of the flavonoid contents indicated that Si may be important in the antioxidant defenses that occurred in response to the droughts, especially in the more drought-sensitive grass species. The exogenous application of silicon could alleviate the oxidative stress of the plants through the modification of the biosynthesis of reactive species and the transcriptional regulation of multiple defense pathways, such as antioxidant enzymes, antioxidant active substances, and also flavonoid compounds [ 34 , 35 ].…”

Silicon as a Smart Fertilizer for Sustainability and Crop Improvement

“…The effect of Si application on several plant species has been proven for several decades, and research has shown numerous advantageous effects of Si on different plant attributes including vegetative growth, development, production, and reduction of biotic and abiotic stress [ 3 , 4 , 5 , 6 ]. Other Si-driven benefits include increase in photosynthetic rate, lower transpiration rate, and resistance to UV-B radiation [ 7 ].…”

Transcriptomic and metabolomic reveals silicon enhances adaptation of rice under dry cultivation by improving flavonoid biosynthesis, osmoregulation, and photosynthesis

“…The accumulation of these flavonoids and derivatives is important during an environmental stress response. Flavonoids have been reported to play a role in the maintenance of ROS homeostasis ( Chen et al, 2019 ; Mavrič Čermelj et al, 2021 ) also. In the present study, higher ROS levels (H 2 O 2 and O 2 – activity) were also detected in rice under dry cultivation compared with flooding treatment ( Figure 1 ).…”

“…Drought and its relationship with silicon have been well studied. For example, in some plants such as sugarcane ( Saccharum officinarum L.), wheat ( Triticum aestivum L.) under drought stress, silicon increases ascorbate peroxidase activity, total soluble sugars content, relative water content ( Mavrič Čermelj et al, 2021 ). In some studies, on rice ( Oryza sativa L.) was found in Si induced different responses regarding to proline accumulation which could be beneficial for drought exposed plants ( Mauad et al, 2016 ).…”