FIGURE 4.

Analysis of ABA-induced leaf senescence. (A) Leaves detached from WT, mutant and overexpressing plants were floated on sterile water (– ABA) or 50 μM ABA for 5 days (+ ABA). (B) Chlorophyll content of detached leaves treated with sterile water (– ABA) or 50 μM ABA for 5 days (+ ABA). Each value represents the mean ± SD. (C) Real-time RT-PCR analysis of SAG12 in the leaves of WT and mutant plants under standard growth conditions (– ABA) or following 5 or 24 h exposure to 20 μM ABA (+ ABA). WT SAG12 expression was set to 1 in both control and ABA treatment. Each value represents the mean ± SE. Significant differences relative to the WT are shown as follows: ^∗P < 0.05 and ^∗∗P < 0.01.