PsaF | PSI-F subunit of photosystem I (plant)

Immunoblot analysis of photosynthetic complex accumulation in wild-type tobacco and the two ?psaI lines grown under low, intermediate, and high-light conditions. Because the accumulation of most tested proteins was highest under high-light conditions, lanes one to three contain samples diluted to 25%, 50%, and a 100% sample of wild-type tobacco grown under high-light conditions, to allow for semi-quantitative determination of changes in protein abundance. Lanes four and five contain the two transplastomic lines grown at 1000 µE m?2 s?1. Lanes six to eight contain wild-type tobacco and the mutants grown at intermediate light intensities, and lanes nine to eleven contain samples grown at low light intensities. For PSII, the accumulation of the essential subunits PsbB (CP43) and PsbD (D2) and the LHCB1 antenna protein were determined, while for the cytochrome b6f complex, the accumulation of the essential redox-active subunits PetA (cytochrome f), PetB (cytochrome b6), and PETC (Rieske FeS protein) was tested. AtpB was probed as an essential subunit of the chloroplast ATP. For PSI, in addition to the three essential plastome-encoded subunits PsaA, PsaB, and PsaC, the accumulation of the nuclear-encoded subunits PSAD, PSAH, PSAK, PSAL, and PSAN and of the four LHCI proteins (LHCA1, LHCA2, LHCA3, LHCA4) was determined. Finally, we examined the accumulation of Ycf4, the chloroplast-encoded PSI-biogenesis factor encoded in the same operon as PsaI, and the nuclear-encoded assembly factor Y3IP1.

Changes in the protein levels of photosynthetic components under extended dark exposure in wild-type and gamera-1. Immunoblot detection of photosynthetic proteins from leaves of Ws and gamera-1 plants incubated after dark adaptation for 0, 2, and 4 days was examined. Specifically, essentially thylakoid fractions were assayed to determine the content of the following proteins: ?-subunit of ATP synthase; the D1 protein, OEC17, OEC23, and OEC33 of PSII; Cyt f and Rieske protein of the cytochrome b6f complex; and the F and D subunits of PSI, after extended dark treatment. Proteins were resolved via SDS-PAGE gel based on equal microgram chlorophyll per lane loading and processed as described in Section “Materials and Methods”. The Large subunit of RuBisco and LHCII stained with either CBB or Ponceau red, respectively, are presented here as loading controls. DAD indicates days after dark adaptation.