Figure 2.

Accumulation of the cleavage products of D1 protein in extreme high-light-treated var2 leaves. A, Immunoblot analysis of the cleavage products of D1 protein under normal-light and extreme high-light conditions. Mature leaves of Col and var2 (approximately 6-week-old plants grown under normal conditions) were illuminated in normal-light (180 µmol photons m⁻² s⁻¹) and extreme high-light (2,500 µmol photons m⁻² s⁻¹) conditions for 1 h. Representative immunoblots (normalized by chlorophyll content) using anti-D1 (N-term) and anti-D1 (C-term) antibodies and the bands corresponding to Coomassie Brilliant Blue-stained LHCII are depicted. A selective detection of the areas indicated by the brackets at right is shown in the second panels from top. B, Immunoblot analysis of AEBSF-treated var2 leaves. Detached leaves were pretreated with Ser protease inhibitor (AEBSF) and subsequently incubated under extreme high-light conditions for 1 h. White and black arrowheads indicate specific and nonspecific signals, respectively, under high-light irradiation.