title: Inhibition of photosynthetic oxygen evolution and electron transfer from the quinone acceptor QA- to QB by iron deficiency.
abstract: The effect of iron deficiency on photosynthetic electron transport in Photosystem II (PS II) was studied in leaves and thylakoid membranes of lettuce (Lactuca sativa, Romaine variety) plants. PS II electron transport was characterized by oxygen evolution and chlorophyll fluorescence parameters. Iron deficiency in the culture medium was shown to affect water oxidation and the advancement of the S-states. A decrease of maximal quantum yield of PS II and an increase of fluorescence intensity at step J and I of OJIP kinetics were also observed. Thermoluminescence measurements revealed that charge recombination between the quinone acceptor of PS II, Q(B), and the S(2) state of the Mn-cluster was strongly perturbed. Also the dark decay of Chl fluorescence after a single turnover white flash was greatly retarded indicating a slower rate of Q(A)(-) reoxidation.
authors.affiliation: Groupe de Recherche en Biologie Végétale (GRBV), Université du Québec à Trois-Rivièrs, Trois-Rivières, QC, Canada.
authors.forename: Najoua
authors.initials: N
authors.lastname: Msilini
authors.forename: Maha
authors.initials: M
authors.lastname: Zaghdoudi
authors.forename: Sridharan
authors.initials: S
authors.lastname: Govindachary
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Lachaâl
authors.forename: Zeineb
authors.initials: Z
authors.lastname: Ouerghi
authors.forename: Robert
authors.initials: R
authors.lastname: Carpentier
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D004579:Electron Transport; D005453:Fluorescence; D007501:Iron / Q000378:metabolism*; D018545:Lactuca / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D011809:Quinones / Q000378:metabolism; D020524:Thylakoids / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D045332:Photosystem II Protein Complex; D011809:Quinones; D014867:Water; D002734:Chlorophyll; D007501:Iron; D010100:Oxygen