Figure 10.

PI3K is involved in dark-induced leaf senescence but not through the regulation of V-ATPase activity. A, The detached Arabidopsis leaves of pi3k-1 mutant and wild-type Arabidopsis were put into dark for 3 d, and the phenotype of leaves was taken. Photochemical efficiency (B) and chlorophyll content (C) of the detached leaves were shown. D, Determination of V-ATPase activity in pi3k-1 mutant and wild-type Arabidopsis after dark treatment for 3 d. E, Vacuolar acidification was observed using AO in pi3k-1 mutant and wild-type Arabidopsis leaves for 3 d after dark treatment. F, The alteration of stomatal aperture was examined by microscopy. Each bar represents three replications. Asterisks (*) indicate significant difference by t test from no dark treatment (*, P < 0.05). Hash marks (#) indicate statistically significant differences between indicated samples (P < 0.05; Student’s t test). Fv/Fm = maximum quantum yield of PSII electron transport (maximum variable fluorescence/maximum yield of fluorescence).