Figure 8.

ESR1 Functions Downstream of WIND1 in in Vitro Shoot Regeneration.

(A) Shoot regeneration of wild-type, WIND1-SRDX, esr1-D, and WIND1-SRDX esr1-D root explants in vitro. Root explants were cultured on CIM for 4 d and transferred to SIM. Representative images of root explants cultured on SIM for 21 d are shown.

(B) Quantitative analysis of shoot regeneration phenotypes. Regeneration phenotypes are scored as a number of regenerating shoots per explant. Data are mean ± se (n ≥ 50 per genotype). Statistical significance was determined by a Student’s t test (***P < 0.001). Note that ectopic induction of ESR1 is sufficient to rescue the shoot regeneration phenotypes in WIND1-SRDX explants.

(C) Induction of WIND1 and ESR1 promoter activities in callus developing from root explants on SIM. Root explants from Pro_WIND1:GUS, Pro_ESR1:GUS, and Pro_ESR1:GUS WIND1-SRDX plants were cultured on CIM for 4 d and transferred to SIM. Note that the promoter activity of ESR1 is strongly reduced by dominant repression of WIND1. Representative images at 1 d after transfer to SIM are shown. Bars = 500 µm in (A) and 100 µm in (C).