Figure 1.
Chlorophyll analysis and fluorescence emission spectra of C. reinhardtii cells.
A) Chlorophyll content, B) room temperature emission spectra, C) 77K spectra emission spectra, (insert, quantification of the PSI and PSII based on the Figure 1B), and D) 77K emission spectra normalized at 680 nm.
Figure 2.
Fractions of PSI-LHCI supercomplexes from solubilized thylakoid membranes by sucrose density centrifugation. F1 (LHCII), F2 (PSI-LHCI and PSII), F3 and F3' (Both contains PSI-LHCI supercomplexes).
Figure 3.
Visible CD spectra of isolated PSI–LHCI supercomplexes from control and Fe stress C. reinhardtii cells.
The Chl content of the samples was adjusted to 10 µg/mL. CD was measured in absorbance units and for easy comparison it was normalized the spectra at 750 nm.
Figure 4.
Green gel electrophoresis of PSI-LHCI supercomplexes.
Lane 1- Control PSI-LHCI supercomplexes, and Lane 2-PSI-LHCI supercomplexes isolated from Fe deficient culture.
Table 1.
Trapping lifetimes obtained from streak camera measurements.
Figure 5.
Representative fluorescence decay-associated spectra (FDAS) obtained from fluorescence streak camera measurements from isolated PSI-LHCI supercomplexes of C. reinhardtii grown under control and Fe deficient conditions.
Fluorescence decay lifetimes are 32–34 ps (A), 120–220 ps (B), and 3–4 ns (C). Each curve shown is the average of the fitted curves from the three data sets collected for each sample.
Figure 6.
Immuno blot of PSI core subunits were identified from isolated PSI-LHCI supercomplexes.
PsaA, PsaB were stable under Fe deficiency conditions while PsaC, PsaD and PsaE content decreased under Fe deficiency. PsaC and PsaD are decreased after 72 hours of Fe deficiency, while PsaE is completely absent in the Fe deficient sample after 72 hours. Lane 1- control, lane 2- 24 h under Fe deficiency, lane 3- 48 h under Fe deficiency, and lane 4- 72 h under Fe deficiency. The bar diagram represents the quantity of the respective protein measured using quantity one 1D analysis software (Biorad).
Figure 7.
Immuno blot of Lhca 1–9 polypeptides were identified from isolated PSI-LHCI supercomplexes.
Lhca 1 and Lhca 9 were more susceptible to Fe deficiency conditions. Lhca 6 was more stable compare to all other LHCI subunits. Lane 1- control, lane 2- 24 h under Fe deficiency, lane 3- 48 h under Fe deficiency, and lane 4- 72 h under Fe deficiency. The bar diagram represents the quantity of the respective protein measured using quantity one 1D analysis software (Biorad).
Figure 8.
Isoform separation and SOD activity of thylakoid membranes.
A) SOD isoforms identified with native staining and B) SOD activity of different isoforms assayed from thylakoid membranes. Lane 1- control thylakoids, and lane 2- thylakoids isolated from cells under Fe deficiency.