The lower levels of plastocyanin
, as a consequence of Cu deficiency, may decrease the efficiency of photosynthetic electron transport in photosystem I and thus impair the CO2 fixation rate, in such a way that starch and soluble sugars content (especially sucrose) are reduced.
Cyt f: This protein is associated with cytochrome b6/f complex and is involved in the electron transfer through plastocyanin
. Its expression was small in dark grown seedlings and increased in green seedlings grown under different light regimes as W, R+FR, FR, V+, R+B.
In oxygenic photosynthesis, the electron transport from water to [NADP.sup.+] is mediated by two photosystems, operating in series through a chain of redox transporters that comprises plastoquinone, the cytochrome [b.sub.6],f complex and plastocyanin
. The electrons extracted from the water flow through PSII, the intersystems transport chain and PSI, in this order, to reduce [NADP.sup.+] and generate the transthylakoid difference in proton electrochemical potential that drives ATP formation.
Cytochrome f and plastocyanin
: their sequence in the photosynthetic electron transport chain of Chlamydomonas reinhardtii.
1 ribulose bisphosphate carboxylase 107 2 chlorophyll a/b-binding protein 13 3 ferredoxin i 13 4 fructose-bisphosphate aldolase 1 12 5 oxygen-evolving enhancer protein 11 6 nonspecific lipid-transfer protein 11 7 plastocyanin
7 8 glyceraldehyde 3-phosphate dehydrogenase 7 9 no similarity 6 10 10-kDa protein precursor 6 11 photosystem I subunit IV 6 12 caffeic acid O-methyltransferase 5 13 ribulose-bisphosphate carboxylase activase 5 14 no similarity 5 15 function unknown 5 16 photosystem II 10-kDa polypeptide 4 17 drought inducible protein 4 18 endopeptidase CIp 4 19 aldo/keto reductase 4 20 no similarity 4 21 Immature-pod Homologous group Putative genes No.