Effects of overexpression and repression of OsDER1. A, Changes in the levels of ubiquitinated proteins in transgenic rice seeds with increased and repressed expression of OsDER1. Immunoblot analysis of the ubiquitinated proteins was performed with anti-α-ubiquitin (α-Ub). The loading control is shown in Supplemental Figure S5C. B, Changes in the expression of BIP1, PDI2-3, and CNX in seedlings (wild type [WT], OE, and Ri) treated with 2 mm DTT for 4 h. Equal volumes of water were added as negative controls. C to F, The growth of OsDER1-overexpressing and OsDER1-repressed rice (OsDER1 OE and OsDER1 Ri) in liquid Murashige and Skoog (MS) medium with and without 1 mm DTT refreshed daily was observed over a period of 2 weeks. Wild-type rice served as a control. C and E, Representative images of wild-type, OsDER1 OE, and OsDER1 Ri rice in the presence and absence of 1 mm DTT after 2 weeks. D and F, Quantitative measurements of the lengths of shoots and roots of wild-type, OsDER1 OE, and OsDER1 Ri seedlings in three trials. Error bars represent sd. *, P < 0.05 and **, P < 0.01 (Student’s t test).