Olive Tree Belowground Microbiota: Plant Growth-Promoting Bacteria and Fungi

The olive tree is one of the most significant crops in the Mediterranean region. Its remarkable adaptability to various environments has facilitated olive cultivation across diverse regions and agricultural scenarios. The rising global demand for olive products, coupled with climate challenges, is driving changes in cultivation methods. These changes are altering the traditional landscape and may potentially reshape the structure and composition of orchard microbial communities, which can impact productivity and stress tolerance. Bacterial and fungal communities naturally associated with plants have long been recognized as crucial for plant growth and health, serving as a vital component of sustainable agriculture. In this review, we aim to highlight the significance of olive cultivation and the impact of abiotic stresses. We update the current knowledge on the profiles of rhizosphere and root fungal and bacterial communities in olive orchards and examine how (a)biotic factors influence these communities. Additionally, we explore the potential of plant growth-promoting bacteria and fungi in enhancing olive physiological performance and stress tolerance. We identify knowledge gaps and emphasize the need for implementing new strategies. A comprehensive understanding of olive-associated microbiota will aid in developing sustainable agronomic practices to address climatic challenges and meet the growing demand for olive products.