Figure 2.

Physiological Effects of pam71-1 on Chloroplasts.

(A) Accumulation of thylakoid membrane complexes in the wild type and pam71-1. Thylakoid membranes (equivalent to 25 µg of chlorophyll) were solubilized with 1% (w/v) β-dodecyl maltoside, and protein complexes were fractionated by Blue-Native gel electrophoresis. The positions of protein complexes (trimeric LHCII = LHCII_trimer, CP43-free PSII complexes = PSII-CP43, PSII monomers = PSII_mono, PSII dimers = PSII_di, PSI monomers = PSI_mono, PSII supercomplexes = PSII_super and PSI-NDH) are indicated.

(B) Electron micrographs of wild-type and pam71-1 leaf sections (top panel), chloroplasts (middle panel), and views of wild-type and pam71-1 chloroplasts at higher magnification (bottom panel). Epidermis (E), palisade layer (PL), spongy layer (SL), starch (St), grana thylakoids (GT), and stroma thylakoids (ST) are indicated.

(C) Starch contents (St; µmol C₆ g fresh weight⁻¹) of wild-type and pam71-1 leaves harvested at three different time points during the day were determined enzymatically. Mean values (±sd) are each based on three individual plants.

(D) Net CO₂ assimilation rate A_n (µmol CO₂ m⁻² s⁻¹). The rate of net CO₂ fixation was recorded in the range of 0 to 1000 µmol photons m⁻² s⁻¹ PAR (photosynthetically active radiation) under atmospheric (400 ppm) or high CO₂ (2000 ppm) conditions. Mean values (±sd) are each based on five to six individual plants.