Fig. 1

WG3 regulates grain width by affecting cell proliferation in rice. (A) Plant architecture of R498 and wg3 at the mature stage. Scale bar, 10 cm. (B) Comparison of grain width between R498 and wg3. Scale bar, 3 mm. (C-E) Statistical analysis of grain width (C), grain length (D), and 1000-grain weight (E) between R498 and wg3. (F) Spikelet hulls of R498 and wg3 before flowering. Scale bar, 3 mm. (G, H) Cross-sections of the spikelet hulls of R498 and wg3. The position of the cross-section is indicated by a black dotted line in F. Scale bars, 200 μm. (I-J) Magnified views of the cross-section boxes in G and H. Scale bars, 50 μm. (K, L) Comparison of cell area (K) and cell number (L) in the outer parenchyma layer. (M) Schematic diagram of the WG3 gene, and alignment of WG3 sequences between ZH11 and WG3-KO mutants. The GRAS domain, knockout target site, and the mutation site in wg3 are shown. The PAM sequences are highlighted in red and the target sequences are highlighted in blue. (N) Plant architecture of ZH11 and WG3-KO mutants at the mature stage. Scale bar, 10 cm. (O) Comparison of grain width between ZH11 and WG3-KO mutants. Scale bar, 3 mm. (P-R) Statistical analysis of grain width (P), grain length (Q), and 1000-grain weight (R) between ZH11 and WG3-KO mutants. Data are given as means ± SD [n = 3 replicates, and each replicate contained five plants in (C-E); n = 20 in (K, L); n = 6 plants in (P-R)]. Significant differences between wild type and corresponding mutants (*P < 0.05 and **P < 0.01) were determined using a Student’s t-test