Editorial: Abiotic and Biotic Stress Responses of Olive Trees Under Climate Change

Giovanni Caruso¹Marco Romi²Giampiero Cai^2*

• ¹Universita degli Studi di Pisa, Pisa, Italy
• ²Dipartimento Scienze della Vita, University of Siena, Siena, Italy

drought on 'Shengeh' cultivar. This treatment significantly improved pomological characteristics, oil content, photosynthetic efficiency, antioxidant enzyme activity, and uptake of essential ions such as Ca2+ and K+, while reducing Na+ accumulation. These results pave the way for the use of nanotechnology to improve resilience in agriculture.At the same time, water management through precision agriculture techniques is increasingly important. Carella et al. (2024) combined proximal and remote sensors to assess the water status of the 'Calatina' cultivar. They established relationships between the thermal imagery derived crop water stress index (CWSI) and stem water potential (Ystem), as well as between different remote sensing vegetation indices (e.g. NDVI, WI, GNDVI) and crop water status. This study provides a basis for efficient irrigation systems that can optimize water use in water-scarce environments.Finally, biotic threats, particularly the bacterium Xylella fastidiosa, represent an emerging stress factor exacerbated by climatic conditions. La Notte et al. ( 2024) conducted an extensive survey of natural olive resources in the Puglia epidemic area, identifying spontaneous genotypes resistant to Xylella. Parentage analysis revealed that the cultivar 'Leccino', known for its resistance, was a common parent for 67% of the progeny showing highly resistant, resistant or tolerant phenotypes. At the transcriptomic level, the highly resistant genotype S105 showed the least perturbation in gene expression in response to Xylella infection, indicating greater resilience compared to other resistant genotypes.Resistance mechanisms include the ability to isolate the bacterium in xylem vessels and to cope with pathogen-induced water stress. This study confirms the value of 'Leccino' as a parent line for Xylella resistance breeding programs and provides gene targets for future genome editing techniques. Other pathogens, such as Pseudomonas savastanoi, which causes tumors on olive trees, are also being studied. Lavado-Benito et al. ( 2024) investigated the role of the GacA system in the virulence and competitiveness of this bacterium and demonstrated that GacA modulates motility, oxidative stress resistance, and virulence. Understanding these pathogen mechanisms is critical for developing integrated defense strategies that contribute to the overall health and resilience of olive trees.In summary, the picture emerging from these studies is clear: olive production in the era of climate change requires an integrated approach. This includes identifying and exploiting genetic diversity (both existing cultivars and wild genotypes) to select more resilient cultivars, understanding the underlying molecular and physiological mechanisms of stress responses, applying advanced technologies for precision management, and developing novel interventions such as nanotechnology to enhance stress tolerance. These combined efforts are essential to ensure a sustainable future for the olive tree and its valuable products.