Figure 2.

SL triggers SMAX1 and SMXL2 degradation through D14.

(A–C) Relative fluorescence from the SMAX1-mScarlet-I reporter (A), the SMXL2-mScarlet-I reporter (B), or the SMAX1_D2-mScarlet-I reporter (C) and the Venus reference after transient expression of the ratiometric system in wild-type (WT) tobacco and Nbd14 is shown. Leaf discs were treated with acetone, 10 μM KAR₁, or 10 μM GR24^5DS for 12 h before measurement. n = 5–8 leaf discs. Asterisks indicate significant differences from each acetone control or between compared pairs using Student's t test (∗p < 0.05 and ∗∗p < 0.01).

(D and E) Relative fluorescence from the SMAX1-mScarlet-I reporter (D) or the SMXL7-mScarlet-I reporter (E) along with D14, d14^seto, d14^S97A, or an empty vector (EV) expressed in Nbd14 at 0, 1, and 2 h after 10 μM GR24^5DS treatment. n = 12 leaf discs. ns, no significance. ∗p < 0.05, ∗∗p < 0.01, Student's t test comparisons with the relative fluorescence at 0 h or between compared pairs.

(F and G) SMAX1_D2-luciferase (LUC) transgenic seedlings in the Col-0, kai2, d14-1, and max2 backgrounds were treated with 5 μM KAR₂(F), 5 μM GR24^5DS(G), or acetone for 4 h. Bioluminescence is shown as relative LUC activity at 0, 2, and 4 h after treatment. n = 12–14 seedlings. ∗p < 0.05, ∗∗p < 0.01, Student's t test comparisons with each genotype/treatment at 0 h.