Figure 6.

Truncated bZIP28 Upregulates the Expression of ER Stress Genes without TM Induction.

bZIP28ΔC, a truncated form of bZIP28 without the TMD and lumen-facing domain, was expressed in transgenic seedlings.

(A) Several genes, known to be upregulated by TM treatment, were assessed by quantitative RT-PCR for expression promoted by bZIP28ΔC without TM treatment. PDIL (protein disulfide isomerase-like protein; At1g21750), CRT1 (calreticulin-1; At1g56340), and CNX1 (calnexin-1; At5g61790). Relative expression is represented as the ratio of PCR efficiency in comparing the threshold cycles of the target cDNA to an actin gene reference. Error bars indicate se (n = 3). Statistical analysis showed that differences between empty vector control (wt) and 35S:bZIP28ΔC transgenic seedlings were significant (P = 0.05).

(B) Comparison in growth of 10-d-old wild-type and bZIP28ΔC transgenic seedlings. Bar = 10 mm.