Rapid and selective disruption of photosystem I in toxic cyanobacteria protects aquatic ecosystem health

초록

The photosynthetic machinery is central to energy capture in phototrophs, yet small molecules that selectively target core complexes remain scarce. Here, we identify a novel photosystem inhibitor, dioxophenamine (DOPHA), through a natural product-like compound screen. DOPHA binds selectively to photosystem I (PSI) across phylogenetically diverse phototrophs, inducing rapid chlorophyll quenching and suppression of oxygen evolution in Microcystis aeruginosa. This response is accompanied by the extracellular release of phycobilisomes and the destabilization of PsaA-containing PSI assemblies. Biochemical analyses, microscale thermophoresis, and in silico docking support a direct interaction between DOPHA and PsaA-associated subunits within PSI. DOPHA also triggers chlorophyll depletion in bacterial, algal, and plant phototrophs, revealing a conserved vulnerability of PSI to targeted disruption. To our knowledge, DOPHA is the first compound shown to directly disassemble PSI, offering a tool for phototroph control and functional dissection of photosynthetic systems.

키워드