Enhancing Plant Resilience to Abiotic Stress: The Power of Biostimulants

Abiotic stresses such as drought, heat, salinity, and heavy metal contamination severely affect global agricultural productivity. Between 2005 and 2015, droughts caused losses of approximately USD 29 billion in developing countries, and from 2008 to 2018, droughts accounted for over 34% of crop and livestock yield losses, totaling about USD 37 billion. To support the growing human population, agricultural output must increase substantially, necessitating a 60%-100% rise in crop productivity to meet the escalating demand. To address environmental challenges, organic, inorganic, and microbial biostimulants are increasingly employed to enhance plant resilience through various morphological, physiological, and biochemical modifications. Plant biostimulants enhance plant resilience under abiotic stress through mechanisms such as abscisic acid signaling modulation, which regulates stomatal closure to reduce water loss during drought and heat stress. Additionally, they aid in scavenging reactive oxygen species and stabilizing ion channels, mitigating oxidative damage, and maintaining ionic balance under stress conditions such as salinity. This review summarizes recent advancements in applying these biostimulants, focusing on their roles in triggering morphological, physiological, biochemical, and molecular changes that collectively enhance plant resilience under stress conditions. It also includes a bibliometric analysis of all articles published on biostimulants from 2019 to 2024 and explores future research directions. Emphasis was placed on optimizing biostimulant formulations and understanding their synergistic effects to maximize their efficacy under various stress conditions. By integrating biostimulants into agricultural practices, we can adopt a sustainable strategy to safeguard crop productivity in the face of climate change and environmental stressors.