Xin Zhai

and 5 more

Against the backdrop of global warming, marine heatwaves are projected to become increasingly intense and frequent in the future. This trend poses a potential threat to the survival of corals and has the capacity to lead to the destruction of entire coral reef ecosystems. Although many studies have confirmed the resilience of corals to heat stress, but their ability to withstand repeated heatwave events occurring in nature remains unclear. In this study, focusing on physiological and symbiotic microorganism responses, we examined the adaptation and resilience of Turbinaria peltata after repeated exposed to marine heatwaves. In the first heatwave, From physiological perspective, Turbinaria peltata showed the average values of Chl a and endosymbionts increased, while GST, Caspase-3, CAT, and SOD showed significant decreases (p < 0.05) upon repeated exposure to heatwaves compared to the initial exposure. In terms of bacteria, the abundance of Leptospira which functional prediction indicating potential pathogenicity and intracellular parasitism, increased significantly during the initial exposure to the heatwave. In contrast, probiotic bacteria such as Achromobacter arsenitoxydans and Halomonas desiderata, which might related to mobile elements, biofilm formation, stress-tolerant bacteria, Gram-positive bacteria, nitrogen uptake, and nitrate uptake, showed significant increases during the re-exposure to the heatwave. Overall, the results indicate that Turbinaria peltata adapts to marine heatwaves through physiological regulation and changes in the microbial community.