Figure 7.

XTH activity in Arabidopsis petioles in response to shade signals. XTH activity was measured as XDA in the petioles of Arabidopsis (Col-0) plants grown in low-R/FR (white circles; A) and green shade (gray circles; B) conditions for 5, 8, and 24 h. Control refers to petioles from plants grown in white light (black circles) conditions. Data points represent means ± se (n = 4). Asterisks indicate significant differences (P < 0.05, Student’s t test). Experiments were repeated twice with similar results.