CEPR1 affects aboveground plant growth, yield, and seed size. A to C, CEPR1 mutants show decreased vegetative leaf growth. A, Rosette diameter at 30 d post germination (dpg) for No-0 and cepr1-1. n = 10. B, Rosette diameter at 31 dpg for Col-0 and cepr1-3. n = 4 to 8. C, Representative images of plants in B. Note that cepr1-3 rosette leaves displayed no obvious chlorosis. Bar = 5 cm. D to I, Loss of CEPR1 function results in impaired yield. D, Inflorescence stems of No-0 and cepr1-1 at 50 dpg. E, Inflorescence stems of Col-0 and cepr1-3 at 59 dpg. Bars in D and E = 100 mm. F and G, CEPR1 mutants show reduced yield. Total seed yield per plant is shown for No-0 and cepr1-1 (n = 6–10; F) and for Col-0 and cepr1-3 (n = 4–8; G). H and I, CEPR1 mutants have reduced seed size. Mass of one seed for No-0 and cepr1-1 (n = 3 plants; H) and for Col-0 and cepr1-3 lines (n = 4 plants; I) was determined from ∼100 seeds per plant. Percentages above bars indicate means as a percentage of the wild type. Significant differences were determined by a two-sample Student’s t test: **P < 0.01 and ***P < 0.001. Error bars indicate se. J and K, Distribution of seed size for the wild type and cepr1 in the No-0 (J) and Col-0 (K) backgrounds. n = 4 to 7 plants, 60 to 120 seeds per plant.