Metagenomic profiles of Porites lutea associated bacterial communities from intertidal and subtidal habitats under field and experimental heat stress conditions

This dataset originates from a study investigating the effects of environmental fluctuation on the structure and function of coral-associated bacterial communities. The research used the reef-building coral Porites lutea from intertidal and subtidal habitats as a model system, combining field monitoring with a mesocosm heat stress experiment (29°C vs. 33°C for 7 days). Metagenomic sequencing was employed to characterize the taxonomic and functional profiles of bacterial communities.Key components of the dataset include: Sample Sources: Coral tissue samples were collected from intertidal (3 m) habitats at Luhuitou Reef, Sanya, China. Samples include field-collected specimens (Intertidal Field, Subtidal Field) and laboratory experimental groups under control and heat-stress conditions (Intertidal Control/Heat, Subtidal Control/Heat).Data Processing: Raw sequencing reads were quality-controlled and adapter-trimmed using fastp. The SqueezeMeta pipeline (v1.5.2) was used for assembly (MEGAHIT) and open reading frame (ORF) prediction (Prodigal). Functional and taxonomic annotations were performed by aligning protein sequences against the NCBI non-redundant (nr), KEGG, eggNOG, and COG databases using DIAMOND. Bacterial ORFs were extracted using the SQMtools R package for downstream analyses.Core Data Files: sqm_csv_export_bacteria/: Contains bacterial-focused data tables generated by SqueezeMeta, including contigs, ORFs, taxonomic assignments (taxa), and functional annotations (functions) based on KEGG KO, eggNOG, and COG databases. Temperature.csv: In situ seawater temperature records from intertidal and subtidal habitats. Dailyrange.csv: Diurnal temperature range data for both habitats.Analytical Applications: The data support calculations of taxonomic and functional niche breadth (Levins’ index), functional redundancy indices, differential abundance analysis, co-occurrence network construction, and other ecological metrics. These analyses help reveal how environmental variability selects for bacterial generalists with high functional redundancy and contributes to coral holobiont thermotolerance. This study extends classical niche theory to host-microbiome systems, demonstrating that environmental fluctuations shape bacterial generalists with high functional redundancy, thereby enhancing the thermal resilience of the coral holobiont. The dataset provides a comprehensive metagenomic resource for understanding the adaptive mechanisms of coral-microbial symbioses under environmental variability.