Mangrove wetlands served as critical blue carbon ecosystems widely distributed across tropical and subtropical coastal zones, where their well-developed root systems provide unique habitats acting as hotspots for microbial activity. While viruses are gradually recognized as essential regulators of soil microbial dynamics and biogeochemical cycling, their diversity and ecological roles within the rhizosphere remain poorly understood. Here, we conducted a systematic analysis of viral communities associated with seven mangrove species through quarterly sampling over one year. In total, we identified 791 viral operational taxonomic units (vOTUs), of which only 25 could be classified at the family level, revealing a vast reservoir of previously uncharacterized viral taxa in mangrove rhizospheres. Functional annotation uncovered 298 auxiliary metabolic genes (AMGs) involved in biogeochemical cycling, spanning carbon metabolism, sulfur metabolism, phosphorus acquisition, and vitamin biosynthesis. Furthermore, the widespread co-occurrence of host defense systems alongside corresponding viral counter-defense systems suggests an ongoing coevolutionary arms race between hosts and viruses. Notably, rhizosphere viral communities exhibited temporal stability across seasons but showed significant divergence among mangrove species, providing the first evidence of phylosymbiosis between plants and their rhizosphere viral communities. These findings highlight the intimate connection between plant phylogeny and rhizosphere viral ecology, deepening our understanding of plant-microbe-virus interactions and their contributions to coastal wetland ecosystem functioning.