Mutations in 14-3-3λ and 14-3-3κ confer increased tolerance to C and N starvation. A, Phenotypes of the 14-3-3λ and 14-3-3κ single mutants and the 14-3-3λ 14-3-3k double mutant (14-3-3λ/κ) in response to N starvation. One-week-old WT, 14-3-3λ-2 (14-3-3λ), 14-3-3κ-3 (14-3-3κ) single mutant, and 14-3-3λ 14-3-3k double mutant seedlings grown on MS medium were transferred to N-rich (N+) or N-deficient (N–) liquid medium and photographed 4 days later. B, Relative chlorophyll contents of WT, 14-3-3λ, 14-3-3κ, and 14-3-3λ 14-3-3k seedlings grown under N+ or N– conditions shown in (A). Chlorophyll contents under N+ conditions were set to 100%. Data are means ± sd calculated from four independent experiments. For each experiment, four technical replicates pooling 15 seedlings each were used per genotype (*P < 0.05 by Student’s t test). C and D, Phenotypes of the 14-3-3λ and 14-3-3κ single mutants and the 14-3-3λ 14-3-3k double mutant in response to fixed C starvation. One-week-old WT, 14-3-3λ-2 (14-3-3λ), 14-3-3κ-3 (14-3-3κ) single mutant, and 14-3-3λ 14-3-3k double mutant seedlings grown on MS medium were transferred to MS plates with sucrose (C+) or without sucrose followed by constant dark treatment (C–) for 7 days. The images were recorded after a 7-day recovery. E and F, Survival rates (E) and relative chlorophyll contents (F) of WT, 14-3-3λ, 14-3-3κ, and 14-3-3λ 14-3-3k seedlings described in (C) and (D) following recovery. Chlorophyll contents under C+ conditions were set to 100%. Data are means ± sd calculated from three independent experiments. For each experiment, four technical replicates pooling 15 seedlings each were used per genotype (*P < 0.05; **P < 0.01 by Student’s t test). G, Images showing the onset of leaf senescence in WT, 14-3-3λ, 14-3-3κ, and 14-3-3λ 14-3-3k plants grown under normal light/dark growth conditions. Photographs were taken at 4, 5, and 6 weeks after germination. H, Relative chlorophyll contents of plants grown under normal light/dark growth conditions for the indicated times. The values from 4-week-old plants were set to 100%. Data are means ± sd calculated from four independent experiments. For each experiment, five entire plants (technical replicates) were used per genotype. Asterisks indicate significant differences from WT (**P < 0.01 by Student’s t test).