Thriving across seawater depths: How blue light shapes a large PSI supercomplex and specific photosynthetic traits in the seagrass Posidonia oceanica.

ABSTRACT: Seagrasses are marine flowering plants that perform oxygenic photosynthesis both under high, white sunlight and under low, blue-green light, conditions fundamentally different from those experienced by land plants. Thus far, the adaptation of seagrass photosynthetic machinery to this underwater light gradient remains poorly understood. Here, we investigate the Mediterranean seagrass Posidonia oceanica, an ecosystem engineer thriving from the surface down to 40 m depth, to uncover how it maintains efficient photosynthesis across this gradient. Combining spectroscopy with pigment and blue native-PAGE analysis, we show that P. oceanica maintains a high but stable photosystem I (PSI)/PSII ratio and constant antenna size at all depths, in conjunction with a high abundance of light-harvesting co

SUBMITTER: Charras-Ferroussier Q 

PROVIDER: S-EPMC12902287 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature