Ferredoxins are iron-sulfur proteins that transfer electrons in a wide variety of metabolic reactions (Probable). Mediates alternative electron partitioning in conditions of acceptor limitation at photosystem I. Accepts electrons from photosystem I (PSI) and is capable of electron transfer with FNR, but cannot support photoreduction of NADP(+) (PubMed:20966083). Binds 1 [2Fe-2S] cluster. E(0) is -280 mV. Induced by high light at protein level, but not at transcript level. Strongly up-regulated in response to acceptor limitation at photosystem I (PSI) in plants lacking of photosynthetic [2Fe-2S] ferredoxin (Fd). Belongs to the 2Fe2S plant-type ferredoxin family.