Treatment Mitigates Drought Stress in via Rhizosphere Microbiome Modulation.

The Korean fir tree , an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance drought tolerance using a black yeast-like fungus identified as (AK10). The 16S/ITS metabarcoding analysis assessed the impact of drought and AK10 treatment on the seedlings' rhizosphere microbiome. Results revealed a profound drought influence on the microbiome, particularly affecting fungal mycobiota. Drought-stressed seedlings exhibited elevated Agaricaceae levels, opportunistic fungi generally associated with decomposition. AK10 treatment significantly mitigated this proliferation and increased the relative abundance of beneficial fungi like and , known biocontrol agents and phosphate solubilizers. A notable reduction in the phytopathogenic levels was observed with AK10, alongside an increase in beneficial bacteria, including and . Furthermore, the conducted correlation analysis shed light on microbial interrelationships within the rhizosphere, elucidating potential co-associations and antagonisms. Taken together, the isolated AK10 identified in this study serves as a potential biostimulant, enhancing the drought tolerance in through beneficial alterations in the rhizosphere microbiome. This approach presents a promising strategy for the conservation of this endangered species.