Fig. 4.

Regulation of COPT2, FSD1, ZIP2, and SPL7 gene expression by Cu and light conditions. The relative expression of the (A) COPT2, (B) FSD1, (C) ZIP2, and (D) SPL7 genes was determined by qPCR in 7-day-old WT seedlings grown under Cu deficiency (1/2 MS; –Cu, plain bars) or Cu excess (1/2 MS with 10 µM CuSO₄; +Cu, stippled bars), in LDHC (L, grey bars) or DDHC (D, black bars). Samples were collected at 0h and 12h. The UBQ10 gene was used as reference. mRNA levels are expressed as relative units (r.u.). The bars represent the mean ±SD of three replicates. Means with a different letter are significantly different (P<0.05).