Molecular Responses to Abiotic Stress in Key Woody Perennial Fruit Crops: Genetic, Epigenetic and Microbiota Insights for Crop Resilience and Sustainability in Times of Climate Change

Climate change has a negative impact on crop productivity, yield and product quality. Abiotic stresses such as increased drought, elevated temperatures, flooding, salinity and extreme weather events may severely affect plant development, reproduction, yield and fruit quality. Plants have evolved mechanisms to face stressful conditions and adapt to increased environmental pressures. Intricate molecular processes involving genetic and epigenetic factors and interactions with the sphere of the microbiota have been implicated in the response of plants to abiotic stresses. Deciphering the mechanisms whereby plants perceive and respond to stress and acquire resilience is crucial for developing strategies to counteract current and future climate challenges. The advances in new technologies and methodologies such as next-generation sequencing, multi-omics, GWAS, New Plant Breeding Techniques (NPBTs), have led to the elucidation of various aspects of the complex gene networks and metabolic pathways underlying plant processes as well as plant-microbiota crosstalk involved in the response to abiotic stresses. Although most of this knowledge has arisen from research on model and annual herbaceous plants, recent efforts have begun illuminating the molecular basis of abiotic stress tolerance in woody perennial species. In this review, we will provide a comprehensive overview and discuss the recent findings concerning genetic, epigenetic and microbiome aspects shaping abiotic stress responses, in the context of enhancing tolerance to environmental stressors in important Mediterranean woody fruit crops.