Silicon in the Soil–Plant Continuum: Intricate Feedback Mechanisms within Ecosystems

Abstract

Plants’ ability to take up silicon from the soil, accumulate it within their tissues and then reincorporate it into the soil through litter creates an intricate network of feedback mechanisms in ecosystems. Here, we provide a concise review of silicon’s roles in soil chemistry and physics and in plant physiology and ecology, focusing on the processes that form these feedback mechanisms. Through this review and analysis, we demonstrate how this feedback network drives ecosystem processes and affects ecosystem functioning. Consequently, we show that Si uptake and accumulation by plants is involved in several ecosystem services like soil appropriation, biomass supply, and carbon sequestration. Considering the demand for food of an increasing global population and the challenges of climate change, a detailed understanding of the underlying processes of these ecosystem services is of prime importance. Silicon and its role in ecosystem functioning and services thus should be the main focus of future research.

Interactions of Silicon With Essential and Beneficial Elements in Plants

“…The essentiality of Si for plants has been the matter of a long debate dating back to the 19th century (e.g., J. von Sachs versus E. Wolff and C. Kreuzhage, see Sreenivasan, 1934;Katz et al, 2021). It is now reasonably well established that Si is essential for only a few species of plants, the FIGURE 1 | Number of publications related to silicon in plants from 2010 to 2020, based on Scopus search with the title words: "Silicon" or "Silicate" and "Plants," refined to "Agricultural and Biological Sciences" (March, 2021).…”

“…The essentiality of Si for plants has been the matter of a long debate dating back to the 19th century (e.g., J. von Sachs versus E. Wolff and C. Kreuzhage, see Sreenivasan, 1934 ; Katz et al, 2021 ). It is now reasonably well established that Si is essential for only a few species of plants, the silicophiles, high in Si concentration (see Marschner, 2012 ; Hodson and Evans, 2020 ).…”

Bacillus thuringiensis and Silicon Modulate Antioxidant Metabolism and Improve the Physiological Traits to Confer Salt Tolerance in Lettuce

“…Silicon (Si) is a significant element, covering around 28% of the lithosphere, and lately it has become known as a 'quasi-essential' element according to The International Plant Nutrition Institute [36]. In grasses, the effects of water availability on the silicification process is stronger than in non-grass species [37]. Si led to improvements in the growth traits and yield production, particularly under stress conditions [36,38].…”

Silicate nutrition and its biological mechanisms involved in water use efficiency in sugarcane and energy cane crops under water deficit

“…Silicon is the most abundant element in soil after oxygen, as silicon dioxide (SiO 2 ) comprises 50-70% of the soil mass 9 . In the solution, however, the available Si is in the form of monosilicic acid (H 4 SiO 4 ) at low concentration (~1 mmol L −1 ) 10 . Silicon is a bene cial element absorbed in the form of H 4 SiO 4 , which remains in the same form in the xylem sap and reaches the leaves through the transpiration gradient 11 .…”