elektronide liikumist fotosünteesi elektrontransportahela redutseerunud ferredoksiinilt valk tioredoksiinile katalüüsiv ensüüm, It is an enzyme that catalyses electron transport from a redox ferredoxin (electron transport chain) to a thioredoxin. Ferredoxin-Thioredoxin reductase (FTR) converts an electron signal (photoreduced ferredoxin) to a thiol signal (reduced thioredoxin), regulating enzymes by reduction of specific disulfide groups. It catalyses the light-dependent activation of several photosynthesis enzymes and constitutes the first historical example of a thiol/disulfide exchange cascade for enzyme regulation.