Mangroves, as blue carbon reservoirs, provide a unique habitat for supporting a variety of microorganisms. Among these, bacteria play crucial roles in the biogeochemical processes of mangrove sediments. However, little is known about their community composition, spatial distribution patterns, and environmental driving factors, particularly across the large geographical scales of mangrove wetlands. In this study, the composition and spatial distribution of the bacterial community structure and its response to fifteen physicochemical parameters (including temperature, pH, salinity, moisture, clay, silt, sand, organic carbon (OC), total nitrogen (TN), total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), δ¹³C, δ¹⁵N, and carbon/nitrogen ratio (C/N ratio)) were characterized in 32 sampling locations of six different mangrove habitats from Guangxi, China, applying 16S rRNA gene high-throughput sequencing technology and correlation analysis. Our results indicated that the spatial distribution patterns in bacterial communities were significantly different among the six different mangrove sites, as evidenced by NMDS (non-metric multidimensional scaling), ANOSIM (analysis of similarity), and LDA (linear discriminant analysis) analysis. Composition analysis of bacterial communities showed that overall, Chloroflexi (8.3–31.6%), Proteobacteria (13.6–30.1%), Bacteroidota (5.0–24.6%), and Desulfobacterota (3.8–24.0%) were the most abundant bacterial phyla in the mangrove surface sediments. Redundancy analysis (RDA) further highlighted that salinity, δ¹³C, temperature, δ¹⁵N, and silt were the most critical environmental variables influencing the composition of bacterial communities across the whole mangrove samples. Notably, Chloroflexi, one of the most abundant bacterial phyla in the mangrove wetlands, displayed a significantly positive correlation with OC and a negative correlation with δ¹³C, suggesting its essential role in the degradation of terrestrial-derived organic carbon. These findings support the current understanding of the roles of the bacterial communities and their interactions with environmental factors in diverse mangrove ecosystems.

To investigate light quality how to shape phyllosphere microbial communities on crop leaves, we analyzed the microbiota of lettuces grown under five light treatments: nature light (CK), Red light (RL), Yellow light (YL), Blue light (BL) and white light (WL) using high-throughput sequencing. The results revealed that light quality significantly altered both bacterial and fungal compositions in the lettuces phyllosphere. At the genus level, in comparison with nature light (CK), RL and YL enriched bacterial genera, such as Rothia , Bradyrhizobium , and fungal genera, such as Cladosporium , Phialosimplex . Notably Rickettsia was uniquely enriched under RL, along with fungal genera Trametes and Ramichloridium . Similarly, YL specifically enriched bacterial genera Hyphomicrobium and Novosphingobium , fungal genera Myrothecium , Talaromyces and Sporobolomyces . In contrast, Exiguobacterium and Cystobasidium were enriched across CK, BL, and WL treatments, while Rhodococcus and Pseudocercospora were uniquely abundant under WL treatment. Function prediction further indicated that symbiotrophic fungi were significantly enriched under RL, whereas WL promoted the proliferation of potentially pathogenic bacteria and fungi (e.g., Pseudocercospora ). Collectively, these findings demonstrate that light quality is a key driver of phyllosphere microbial assembly in lettuce. provide new insights into light-driven microbial assembly on lettuce leaves and set the stage for functional studies on plant-microbe interactions under controlled light spectra.