FIN219 and CRY1 regulate each other in modulating hypocotyl elongation of <i>Arabidopsis</i> seedlings under different light conditions.

<p>(A) FIN219 function in regulating light-mediated inhibition of hypocotyl elongation requires functional CRY1 and CRY2. Hypocotyl growth responses of 4-day-old seedlings under different light conditions. (Left to right) Wild type (Col-0), <i>FIN219-OE</i>, <i>cry1</i>, <i>FIN219-OE/cry1</i>, <i>cry2</i>, <i>FIN219-OE/cry2</i>, <i>cry1cry2</i> and <i>FIN219-OE/cry1cry2</i>. Blue light: 2.2 μmol•m^-2•s^-1, far-red light (FR): 3.1 μmol•m^-2•s^-1, red light: 7.5 μmol•m^-2•s^-1, white light: 8 μmol•m^-2•s^-1. Scale bar = 2 mm. (B) Quantification of hypocotyl lengths of seedlings shown in (A). Data are mean ± SD (n ≥ 20). Different lowercase letters represent significant differences by one-way ANOVA at P <0.05. (C) <i>FIN219</i> overexpression in <i>GUS-CCT1</i> transgenic plants can rescue the short-hypocotyl phenotype of <i>GUS-CCT1</i> under all light conditions except red light. Hypocotyl growth responses of 4-day-old seedlings under various light conditions, including the dark. (Left to right) wild type (Col-0), <i>fin219</i>, <i>FIN219-OE</i>, <i>FIN219-OE/GUS-CCT1 #11–21</i>, <i>#13–4</i>, <i>GUS-CCT1</i> and <i>cry1</i>. Blue light: 2.2 μmol•m^-2•s^-1, far-red light (FR): 3.1 μmol•m^-2•s^-1, red light: 7.5 μmol•m^-2•s^-1, white light: 8 μmol•m^-2•s^-1. Scale bar = 2 mm. (D) Quantification of hypocotyl lengths of seedlings shown in C. Data are mean ± SD (n ≥ 20). Different lowercase letters represent significant differences by one-way ANOVA at P <0.05.