Figure 4.

CLE40 fragments generated by SBTs from recombinant proCLE40 are inactive. A, Peptides (C1, C2, N1, and N2) generated by SBTs from recombinant CLE40 precursor (compare with Fig. 3C) aligned with the precursor sequence. The internal PTG motif is highlighted in red. B and C, CLE40 fragments resulting from cleavage at the PTG motif are inactive. Root tips of 5-d-old seedlings were treated with 1 µm matCLE40 and CLE40 fragments C1, C2, N1, and N2. Starch staining reveals a reduction in columella cell layers, as indicated by red asterisks. Bars = 10 µm. C, Root growth is inhibited in matCLE40-treated seedlings as compared with N1-, N2-, C1-, and C2-treated seedlings and controls. Data show means ± se of n ≥ 73 seedlings of one representative experiment out of three independent experiments. Asterisks indicate significant differences from the untreated control using Student’s t test (P < 0.001).