Purification and in vitro assays of the TH-ProCLV3 fusion protein. (A) Affinity purification of TH-ProCLV3. M, molecular weight marker; T, total cell lysate; S, supernatant; P, pellet; B, efflux with binding buffer; W, efflux with washing buffer; E, efflux with elution buffer; arrowhead, TH-ProCLV3. (B) Sizes of SAMs of 8-d-old clv1-1 and clv3-2 seedlings (n = 8) after the treatment with or without 1 μM TH-ProCLV3. Error bar = ± SD. The asterisk indicates significant differences (P < 0.01 by Student’s t-test) between SAM sizes of clv3-2 seedlings with and without TH-ProCLV3 treatments. (C) Root lengths of 8-d-old Ler and clv2-1 seedlings treated with or without 1 μM TH-ProCLV3 (n = 8). Error bar = ± SD. The asterisk indicates significant differences (P < 0.01 by Student’s t-test) between root lengths of Ler seedlings with and without TH-ProCLV3 treatment. (D, E) SAMs of clv1-1 seedlings treated with (E) or without (D) 1 μM TH-ProCLV3. (H, I) SAMs of clv3-2 seedlings treated with (I) or without (H) 1 μM TH-ProCLV3. Note the reduced sizes of the SAMs in clv3-2 seedlings after the treatment with TH-ProCLV3. Arrowheads point to the margins of the SAMs. (F, G) Eight-d-old clv2-1 and Ler seedlings treated with (G) or without (F) 1 μM TH-ProCLV3. (J-M) Root tips of clv2-1 (J, L) and Ler (K, M) seedlings after incubation with (J, K) or without (L, M) 1 μM TH-ProCLV3. Bar in D = 50 μm for D, E, H and I; Bar in F = 1 cm for F and G; Bar in J = 50 μm for J to M.