Sporophytic EIN3-dependent signaling represses endosperm and seed expansion.
(A) Dorsoventral endosperm diameter of wild-type (WT) × WT and ein3/− × WT seeds in the four-nucleate endosperm stage. “All” indicates ein3/+ seeds of ein3/− × WT crosses with and without sdn (n = 289/130/338 for WT seeds/ ein3/+ seeds with no sdn/ all of ein3/+ seeds).
(B) Frequency of WT × WT and ein3/− × WT seeds in different developmental stages 24 h after pollination: unfertilized and freshly fertilized seeds in the one-nucleate endosperm stage (uf/1nES) and two-, four-, and eight-nucleate endosperm staged seeds (2nES, 4nES, and 8nES, respectively) (n = 537/570 for WT/ein3/+).
(C) Mature seed size (n = 689/770/2079 for WT × WT seeds/ein3/− × WT seeds/ein3/+ × WT seeds, respectively).
(D) Independent experiment showing size of WT × WT and ein3/+ × WT mature seeds. Seeds were assigned according to the genotype of their progeny (n = 198/109/130 for WT/segregating WT/segregating ein3/+, respectively). Two-tailed Student’s t-test: ∗∗∗p < 0.001 and ∗∗∗∗p < 0.0001. See also Supplemental Figure 2.