Endophytes and Arbuscular Mycorrhizal Fungi as Bioinoculants for Enhancing Oil Palm (Elaeis guineensis Jacq.) Tolerance to Abiotic Stress: A Review
Oil palm (Elaeis guineensis Jacq.) is a strategically important plantation commodity whose productivity is significantly influenced by environmental conditions. Abiotic stresses, particularly drought, impede plant growth and substantially reduce yield. As the impacts of climate change intensify and pressure on land resources increases, sustainable approaches to enhance plant resilience are increasingly needed. Among these, this study employs a systematic literature review and comparative analysis of globally published scientific literature (2021–2026) to examine the physiological, biochemical, and molecular mechanisms of beneficial microorganisms. Specifically, it synthesizes findings on how endophytes and arbuscular mycorrhizal fungi (AMF) improve plant water and nutrient status, mitigate oxidative stress, and enhance growth and stress tolerance in oil palm (Elaeis guineensis Jacq.) the utilization of beneficial microorganisms such as endophytes and arbuscular mycorrhizal fungi (AMF) has emerged as a promising strategy. This review aims to summarize and analyze the roles of endophytes and mycorrhizae in improving the tolerance of oil palm to various abiotic stresses, based on globally published scientific literature. The synergistic interaction between endophytes and AMF has been shown to positively affect plant nutrient and water status, reduce oxidative stress, and improve growth from the seedling to the mature plant stage under stress conditions. Despite promising findings across multiple studies, field-scale application still faces several challenges, including the selection of compatible strains, formulation stability of inoculants, and optimization of application techniques at the plantation scale. Future research should focus on strain-specific synergism, large-scale inoculant production, and integrated management strategies to translate laboratory findings into practical solutions for sustainable oil palm cultivation.