Figure 8.

CBL4, CIPK26, and OST1 are required for systemic ROS signal propagation, but not initiation, in response to light stress. A, Representative time-lapse images of ROS accumulation in stock and scion parts of grafted plants, generated using WT and cbl4-1 plants, in response to a local HL stress treatment applied to a single leaf (indicated with a circle) belonging to the stock part. Scions are indicated by solid white lines, and stocks are indicated by dashed white lines. B, Bar graphs showing the combined data from the stock and scion of grafted WT plants subjected to HL stress on a single leaf of the stock scion. C, Same as (B), but for different grafting combinations between WT and cbl4-1 plants. D, Same as (B), but for different grafting combinations between WT and cipk26-2 plants. E, Same as (B), but for different grafting combinations between WT and ost1-2 plants. All experiments were repeated at least three times with 10 plants of each genotype per experiment. ROS accumulation was imaged using H₂DCFDA. Data are presented as box plot graphs; X is mean ± se, N = 30, **P < 0.01, ***P < 0.001, Student t test. Scale bar, 1 cm.