Functions of silicon in plant drought stress responses

Abstract

Silicon (Si), the second most abundant element in Earth’s crust, exerts beneficial effects on the growth and productivity of a variety of plant species under various environmental conditions. However, the benefits of Si and its importance to plants are controversial due to differences among the species, genotypes, and the environmental conditions. Although Si has been widely reported to alleviate plant drought stress in both the Si-accumulating and nonaccumulating plants, the underlying mechanisms through which Si improves plant water status and maintains water balance remain unclear. The aim of this review is to summarize the morphoanatomical, physiological, biochemical, and molecular processes that are involved in plant water status that are regulated by Si in response to drought stress, especially the integrated modulation of Si-triggered drought stress responses in Si accumulators and intermediate- and excluder-type plants. The key mechanisms influencing the ability of Si to mitigate the effects of drought stress include enhancing water uptake and transport, regulating stomatal behavior and transpirational water loss, accumulating solutes and osmoregulatory substances, and inducing plant defense- associated with signaling events, consequently maintaining whole-plant water balance. This study evaluates the ability of Si to maintain water balance under drought stress conditions and suggests future research that is needed to implement the use of Si in agriculture. Considering the complex relationships between Si and different plant species, genotypes, and the environment, detailed studies are needed to understand the interactions between Si and plant responses under stress conditions.

Impact of Si on C, N, and P stoichiometric homeostasis favors nutrition and stem dry mass accumulation in sugarcane cultivated in tropical soils with different water regimes

“…Silicon use is a known alternative to alleviate the water deficit in sugarcane crops, but this may depend on the crop's ability to absorb this element. This fact favors sugarcane because it is classified as a plant that accumulates Si, having specific transporters in the roots and high efficiency in absorbing this beneficial element (Wang et al, 2021). Additionally, Si is absorbed by LSi influx channels and transported to other tissues and organs by efflux channels, and the cooperative influx and efflux system regulates plant accumulation patterns (Trejo-Téllez et al, 2022).…”

Variation of soil silicon fractions and bioavailability during centennial‐scale evolution of ecosystem after glacier retreat

“…Previous studies reported that the soil environment with low pH promotes the dissolution of minerals and increases the content of soil mineral elements (Drever & Stillings, 1997). It was reported that the absorption of Si by plants can resist the stresses of pathogens and insect pests (Alhousari & Greger, 2018; Debona et al., 2017; Islam et al., 2020), drought (Thorne et al., 2020; Wang et al., 2021), and heavy metals (Elrys et al., 2018; Khan et al., 2021), and can increase the photosynthetic efficiency of leaves (Bukhari et al., 2021; Verma et al., 2020), thus increasing the vegetation biomass (Gan et al., 2021; Hussain et al., 2019). The increase of vegetation coverage will inhibit the influence of rainfall on soil erosion potential (Kim et al., 2021; Zhuang et al., 2021), thereby alleviating soil erosion in the study area.…”

Importance of silicon in combating a variety of stresses in plants: A review

“…Many results supported the Si application in response to drought stress. The main mechanism underlying the processes includes an increase in uptake and transport of water, accumulation of compatible solutes, increase in osmoprotectant, enhancement in stomatal conductance, and activation of defensive genes involved in stress mitigants, which are all driven by addition of Si in plants under water-deficit conditions (Wang et al, 2021). Sonobe et al (2009) showed an experiment on sorghum plants and found that the addition of Si in the root medium enhanced the uptake of water in plant parts, including stomatal conductance.…”