phototrophy

Edge evidence

• light causes phototrophy biolink:causes

  Light availability is the input the phototrophic trait realizes.

  • DOI:10.1016/j.tim.2006.09.001 Bryant & Frigaard frame phototrophy as the broad use of light for energy.
• phototrophy enables proton motive force RO:0002327

  Chlorophyll- and retinal-based phototrophy generate proton motive force from absorbed light.

  • DOI:10.1126/science.289.5486.1902 Béjà et al. established retinal-based proteorhodopsin phototrophy as a light-driven proton pump, complementing chlorophyll-based photosynthesis.
• light activates rhodopsin photocycle RO:0002213

  Visible light activates the microbial rhodopsin photocycle across taxa.

  • DOI:10.1093/ismejo/wrae175 "All rhodopsins are activated by visible light and return to their original state through a photocycle"; broad rhodopsin mechanism, not limited to one taxon.
• microbial rhodopsin enables rhodopsin photocycle RO:0002327

  During the photocycle, microbial rhodopsins exhibit ion-transport function.

  • DOI:10.1093/ismejo/wrae175 "During the photocycle, they exhibit their cognate protein functions such as ion transport"; general mechanistic edge for rhodopsin phototrophy.
• proton motive force drives ATP synthesis

  The proton gradient drives ATP synthesis, conserving light-derived energy.

  • DOI:10.1128/spectrum.02177-23 "creating a proton gradient to drive the synthesis of ATP"; direct support for rhodopsin-based energy conservation.
• photosystem II supplies electrons to photosynthetic electron transport chain

  PSII water oxidation supplies electrons to the photosynthetic electron transport chain.

  • DOI:10.1111/1751-7915.14519 "electrons from the photo-oxidation of water in PSII are transferred through plastoquinone to cytochrome b6f"; canonical oxygenic phototrophy edge.
• photosynthetic electron transport chain produces NADPH METPO:2000202

  Electron flow through cytochrome b6f and PSI reduces ferredoxin/NADP+ to NADPH.

  • DOI:10.1111/1751-7915.14519 "These electrons are eventually transferred to ferredoxin and NADP+ to form NADPH"; canonical oxygenic phototrophy edge.
• photosynthetic electron transport chain produces ATP METPO:2000202

  Photosynthetic electron transfer establishes a proton gradient that produces ATP.

  • DOI:10.1111/1751-7915.14519 "NADPH and ATP are produced from a proton gradient"; canonical oxygenic phototrophy edge.
• high light intensity damages photosystem II

  High light intensity and resulting free radicals damage PSII (photoinhibition).

  • DOI:10.1111/1751-7915.14519 "High-energy photons and the generation of free radicals damage PSII"; strong environmental inhibitor edge.