Dark treatment of cucumber seedlings and CsTIC21 gene expression analysis. A and B) Comparison of the cucumber seedlings grown in different conditions. Images were digitally extracted for comparison. A) Wild-type (WT) cucumber seeds were planted in the light (left) and dark (right) for 5 d, and then grown in light for the next 5 d B). C) RT-qPCR analysis of CsTIC21 gene expression in the seedlings grown in light and dark conditions for 5 d. D) RT-qPCR analysis of CsTIC21 gene expression in the seedlings grown in light for 10 d and 5 d light + 5 d dark. Data represent mean ± Sd of 3 biological replicates C and D). Student's t-test was performed and statistically significant differences were indicated by **P < 0.01 C and D). Scale bar = 1 cm in A and B).