Fig. 4

Promoter and expression pattern of BnCIPk9 in seedlings, in the presence and absence of sugars. a Composition of putative cis-acting elements in the BnCIPK9 promoter (BnCIPK9 promoter1, 3050 bp from the original fragment; BnCIPK9 promoter2, 3372 bp from the original fragment). b Activity of BnCIPK9 promoter1 in 7-day-old seedlings in the presence and absence of sugars. The transgenic fusion including 3050 bp (BnCIPK9 promoter1) of the 5′-upstream regulatory region of the BnCIPK9, fused to the GUS reporter gene used to generate the transgenic lines (BnCIPK9 promoter1:GUS). c Activity of the promoter2 of BnCIPK9 in 7-day-old seedlings in the presence or absence of sugars. The transgenic fusion included 3372 bp (BnCIPK9 promoter2) of the 5′-upstream regulatory region of BnCIPK9, fused to the GUS reporter gene used to generate the transgenic lines (BnCIPK9 promoter2:GUS). Different sugar sources [1 or 3% glucose (Glu), or sucrose (Suc)] were used; mannitol (Mlt) was used as a control for osmotic stress. Data are shown as means of the relative GUS activity of promoter1 and promoter2 of BnCIPK9± standard deviation (SD) (n = 3). The Student’s t test was performed to evaluate the significance of differences between means at *P < 0.05; **P < 0.01