Biostimulants and their role in increasing cereal crops' resistance to drought stress

Sustainable strategies to enhance crop resilience are increasingly needed as climate change intensifies the frequency and severity of drought events. In recent years, plant biostimulants have gained considerable attention as environmentally friendly tools for improving crop productivity and quality under water-limited conditions. Although numerous studies have reported positive effects of biostimulants, comprehensive assessments of their overall impact on cereals performance remain limited. This review presents the concept and main categories of plant biostimulants and summarizes current knowledge on their effects on plants and soil, with particular emphasis on their role in enhancing drought tolerance in major cereal crops such as wheat, barley, and other cereals. Both non-microbial biostimulants, including humic and fulvic substances, seaweed extracts, vermicompost, and plant growth regulators, and microbial biostimulants, such as PGPR and mycorrhizal fungi, are discussed with regard to their mechanisms of action. Biostimulants contribute to improved drought tolerance by enhancing antioxidant defense systems, photosynthetic efficiency, nutrient and water uptake, and phytohormonal regulation. Overall, the available evidence highlights the potential of biostimulants as sustainable tools for improving cereal productivity, grain quality, and agroecosystem resilience under drought conditions. The reviewed studies indicate that the effectiveness of biostimulants may vary among cereal species, with some crops exhibiting stronger growth and yield responses than others. In addition, this review bridges fundamental research with practical application by outlining key considerations for the effective use of biostimulants in cereal production systems.