Fig. 2

Hg-, Cd-, and Cr-induced expression patterns of HsCIPKs. a-c Relative expression levels of HsCIPKs in four-day-old wild barley seedlings treated for different time lengths (0, 1, 3, 6, 12, and 18 h) with 20 μM HgCl₂ (a), 20 μM CdCl₂ (b), and 0.5 mM K₂Cr₂O₇ (c), respectively. Values shown are means ± SD. Single, double, and triple asterisks indicate P < 0.01, 0.001, and 0.0001, respectively (t test; compared to the corresponding 0-time point mock control). The expression level of the 0-time point mock control for each HsCIPK was set as 1.0