Abstract

Abiotic stress can weaken plants by disrupting their physiological capacity and acting as a predisposing factor. This disruption not only affects the plant's physiology but also impacts the balance of its microbiome, which plays a vital role in enhancing the plant's resistance to stress factors. The diversity and balance of microorganisms in the microbiome are crucial for the plant's health, and any alterations to it can result in symptoms of decline. The stability of the microbiome's functions is closely linked to greater microbial diversity, which improves the plant's ability to respond to stress factors. In 2016, Araucaria araucana, Chile´s national tree, exhibited crown decay and death, which were attributed to the bioclimatic stress experienced by the ecosystem. This stress weakened the trees' ability to respond effectively. The objective of this study was to examine the taxonomic and functional diversity of the soil microbiome in asymptomatic A. araucana trees compared to those showing severe crown death symptoms. Soil samples from decaying A. araucana trees were analyzed to evaluate the composition and diversity of fungal and oomycete communities and their relationship with the disease symptoms. The study found that the taxonomic and functional diversity of the soil in decaying A. araucana trees were correlated with the decay symptoms.