Figure 4.

Expression of GA Biosynthesis Genes and Analysis of GA Levels in Wild-Type and elf3 Plants.

(A) and (B) GA20ox2 expression is elevated in elf3 leaves during the nighttime phase of the diurnal cycle (A), which overlaps (B) with the peak in expression of ELF3 in wild-type plants. Numbers on the x axis refer to time (hour) within the 24-h cycle, with 0 h being dawn (lights on). Black and white rectangles illustrate periods of dark and light, respectively. Data are the mean ± se of three biological replicates and are normalized to GAPDH.

(C) GA20ox2 is expressed equally in the apex of wild-type and elf3 plants but responds to exogenous application of PAC and GA. Data are the mean ± se of three biological replicates, each containing six developing inflorescences. Values are relative to the wild type.

(D) Quantification of GA₁₉, GA₂₀, GA₁, and GA₈ levels in leaves of elf3 plants relative to the wild type. Leaves were harvested from plants at the fourth leaf stage at ZT 0 h (dawn). Data are the mean ± se of four biological replicates.

(E) Quantification of transcript levels for GA3ox1, GA3ox2, GA2ox3, and GA2ox4 in leaves of wild-type and elf3 plants during the day (ZT 5 h) and night (ZT 21 h). Black and white rectangles illustrate periods of dark and light, respectively. Data are the mean ± se of three biological replicates.

(F) Quantification of GA3ox2 and GA2ox3 in the developing apices, as described in (C). Data are the mean ± se of three biological replicates, each containing six developing inflorescences. All data are from plants grown under SDs. (*P < 0.05; **P < 0.01; ***P < 0.001).