Description of ugt80 and ugt713 mutants and seed coat phenotypes. (A) Salk T-DNA insertion mutants for UGT80A2, UGT80B1, and UGT713B1 are indicated in red and a GABI-Kat insertion mutant is shown in black. Exons are displayed as blue boxes. Light blue boxes indicate 3’- and 5’-UTRs. (B) Seed phenotypes for the ugt80 mutants are shown. The ugt80B1 seeds exhibit a transparent testa. Scale bars=500 μm. (C–Z) Scanning electron microscopy of dry seeds from each of eight genotypes: (C, K, S) Col-0 wild type (WT); (D, L, T) ugt80A2; (E, M, U) ugt80B1; (F, N, V) ugt713B1; (G, O, W) ugt80A2,B1; (H, P, X) ugt80A2,713B1; (I, Q, Y) ugt80B1,713B1; (J, R, Z) ugt80A2,B1,713B1. (C–F) Whole seeds. Scale bars=100 μm. (K–R) Magnification showing seed coat details. Scale bars=50 μm. (S–Z) Single mucilage secretory cells with columella in the centre. Scale bars=25 μm. Wild-type seeds have uniform seed coat cells with well-formed columella and cell walls. In contrast, ugt80B1 mutants exhibit shallow columella (red asterisks) and a collapsed region near the funiculus (arrows). ugt80A2 and ugt713B1 mutants display no apparent differences in comparison to wild type.