Heat stress mitigation by silicon nutrition in plants: A comprehensive overview

Abstract

Rapid climatic changes have exacerbated the severity of extreme weather events in agricultural regions, such as rainfall, elevated temperatures, and drought stress. As a result, heat stress (HS) has emerged as one of the most serious abiotic risks to crop development, productivity, and nutritional security due to the continued rise in global mean temperature. According to the IPCC, average global temperatures will rise by 3–6 °C by 2100. Importantly, excessive temperature stress during the reproductive stage results in a significant reduction of crop output. Consequently, there is an urgent need to comprehend food crops’ response and tolerance mechanisms to heat stress. Plants respond to high-temperature stress by initiating a series of physiological, biochemical, and molecular events and adapt by activating many stress-responsive genes. Silicon (Si) is a subtle element that improves plant growth and development and protects it against numerous abiotic and biotic challenges. Several studies have proved that the exogenous application of Si has significantly mitigated the negative impacts of abiotic stresses. However, there have only been a few investigations on the Si’s role in reducing the deleterious consequences of heat stress. Therefore, this chapter summarizes the heat-induced responses and damages in plants. In a few examples, we discuss the versatile functions of Si in mitigating abiotic stresses, including heat stress and Si-mediated molecular mechanisms of heat stress tolerance.