Figure 2.

Manipulation of EIN3 signaling suggests an inhibitory role of synergid-derived nuclei in endosperm expansion.

(A) Representative cleared whole mounts of ein3/− × wild-type seeds at the four-nucleate endosperm stage containing no sdn (left), one sdn (middle), or two sdn (right) (n = 338). Endosperm nuclei, black arrowheads; sdn, white arrowheads; zygote, asterisk.

(B) Deviation of dorsoventral endosperm diameter of ein3/− × wild-type seeds segregating either one or two sdn at the four-nucleate endosperm stage from the seeds segregating no sdn (n = 130/107/101 for no sdn/1sdn/2sdn, respectively). Endosperm diameter of seeds with either one or two sdn is shown relative to endosperm diameter of seeds without sdn.

(C) Time interval between nuclear disintegration of the two-nucleate and the four-nucleate endosperm stage (n = 42/36 for no sdn/sdn).

(D) Dorsoventral endosperm diameter of ein3-c1/− wild-type seeds segregating no, one, or two sdn at the four-nucleate endosperm stage (n = 45/70/207 for no sdn/1sdn/2sdn, respectively). Endosperm diameter of seeds with either one or two sdn is shown relative to endosperm diameter of seeds without sdn. See also Supplemental Figure 1D–1F.

(E) Dorsoventral endosperm diameter of pDD2::EIN3_SRDX × wild-type young seeds at the four-nucleate endosperm stage. L1, L2, and L3 indicate independent pDD2::EIN3_SRDX lines (n (L1) = 81/104; n (L2) = 73/16; n (L3) = 85/49 for no sdn/sdn, respectively). Data indicate the mean ± SEM. Scale bar, 20 μm. Two-tailed Student’s t-test: ∗p < 0.05; ∗∗∗p < 0.001.