Enhancing Abiotic Stress Resilience in Mediterranean Woody Perennial Fruit Crops: Genetic, Epigenetic, and Microbial Molecular Perspectives in the Face of Climate Change

Abstract

Enhanced abiotic stresses such as increased drought, elevated temperatures, salinity, and extreme weather phenomena severely affect major crops in the Mediterranean area, a 'hot spot' of climate change. Plants have evolved mechanisms to face stressful conditions and adapt to increased environmental pressures. Intricate molecular processes involving genetic and epigenetic factors and plant-microbe interactions have been implicated in the response and tolerance to abiotic stress. Deciphering the molecular mechanisms whereby plants perceive and respond to stress is crucial for developing strategies to counteract climate challenges. Progress in determining genes, complex gene networks, and biochemical pathways, as well as plant-microbiota crosstalk, involved in abiotic stress tolerance has been achieved through the application of molecular tools in diverse genetic resources. This knowledge could be particularly useful for accelerating plant improvement and generating resilient varieties, especially concerning woody perennial crops, where classical breeding is a lengthy and labor-intensive process. Similarly, understanding the mechanisms of plant-microbe interactions could provide insights into innovative approaches to facing stressful conditions. In this review, we provide a comprehensive overview and discuss the recent findings concerning the genetic, epigenetic, and microbial aspects shaping abiotic stress responses, in the context of enhancing resilience in important Mediterranean woody perennial fruit crops.

Keywords: drought; epigenome; microbiome; salinity; tolerance.

Figure 1

A schematic view of the factors influencing the response to abiotic stresses and plant–microbe interactions in woody fruit species. Abiotic stresses such as drought, temperature, salinity, and cold induce stress response mechanisms that lead to plant tolerance and adaptation. Soil properties, water and nutrient availability, and the synergies of the genome, the epigenome, and the microbiome are crucial elements for proper plant growth and stress resilience under adverse conditions. Beneficial microorganisms such as rhizosphere microbial communities are involved in many physiological and molecular processes and can promote plant growth, increase water and nutrient uptake, and enhance resilience to environmental stresses. These activities depend on genetic, epigenetic, and microbial factors and soil physicochemical properties and entail intricate gene networks and epigenetic regulation such as DNA methylation (red circles), histone modifications (blue triangles), and the action of small noncoding RNAs modulating gene expression dynamics.