Silicon and salicylic acid: individual and combined impact on plant growth and stress tolerance

Abstract

The importance of individual and combined effects of silicon Si (Si) and salicylic acid (SA) has become increasingly evident in recent years. Their absorption, transportation in plants, and role in growth and stress physiology are investigated in different studies at different levels. It was shown that Si and SA play substantial roles in growth promotion and in providing advantageous responses to biotic and abiotic stresses. Nutrients deficiency stress and metal toxicity, particularly boron, and cadmium stress, and bacterial and fungal infections, were suppressed after the foliar application of Si and SA. In most cases, Si + SA treatment elevated the photosynthetic rate and relative water content of leaves and diminished the oxidative stress, resulting in better growth and productivity. It was also stated that Si affects the endogenous supply of SA by regulating the biosynthetic pathway; furthermore, SA increases the Si absorption rate. In this review article, we attempted to summarise research that shared comparable fundamentals of Si and SA absorption, transport, and molecular control, as well as their significance in the stress physiology of plants. So, these findings may contribute towards improved sustainability and productivity for many crop plants.