LHC phylogeny data

Photosynthesis is the fundamental process for the survival of photosynthetic organisms. The light harvesting complexes (LHCs) play a crucial role in light energy capture and transfer. Despite their conserved role in energy transfer, the evolutionary basis for functional diversification of LHCs across photosynthetic lineages remains largely unclear. In this study, we performed phylogenetic analyses based on 65 genomes covering all major linages of photosynthetic organisms and identified 1,922 LHC proteins, which were classified into four groups: LHCA, LHCB, LHC-like, and FCP. The <i>LHC</i> gene family has undergone dynamic diversification through lineage-specific mechanisms in which green algae primarily utilized dispersed duplications, while land plants increasingly relied on whole-genome duplications (WGDs). Structural analyses revealed key adaptive modifications: PSI-LHCI transitioned from a double-layer crescent antenna in green algae to a simplified single-layer configuration in land plants, while PSII-LHCII in angiosperms replaced the N-LHCII trimer with CP24 to optimize light harvesting. Expression profiling highlighted the functional diversification of LHC members, with LHCA/LHCB members showing constitutive expression in photosynthetic tissues and strong induction under abiotic stress, while LHC-like proteins exhibited specialized responses to specific environmental challenges. This study enhances our understanding of the functions of LHC proteins in the evolution of photosynthesis, and provides the theoretical foundation for future research on the molecular mechanisms underlying the adaptive evolution of LHCs in extreme environments.