ABSTRACT Newly differentiated leaves of albino ornamental kale turn white as exposed to low temperatures, producing a distinctive and commercially desirable unique color pattern. Here, we show that this low‐temperature‐induced albinism is caused by a mutation in the kale F‐box gene BoWl . Using yeast two‐hybrid, pull‐down, co‐immunoprecipitation, and luciferase complementation assays, we demonstrate that BoWl interacts with the transcription factor BoARF1 to form a functional complex. Complementary yeast one‐hybrid, electrophoretic mobility shift, chromatin immunoprecipitation, and luciferase assays reveal that this complex activates BoGLK1 , a regulator of chloroplast development and chlorophyll synthesis. In the albino line, a mutation in BoWl results in abnormal chloroplast structure and disrupts chlorophyll synthesis. We further identify BoCBF1/BoPHL2 as a low‐temperature responsive regulatory module that transcriptionally activates BoWl expression. Together, these findings define a molecular pathway linking cold perception to transcriptional regulation associated with leaf whitening in ornamental kale, providing new insight into how low temperature influences genetically controlled leaf color variation.
Gong et al. (Thu,) studied this question.