Figure 12.

Relationship between the UPR and Ectopic Lignin Deposition in the lig Mutant.

(A) RT-PCR analysis of BiP3 expression. Total RNA was isolated from seedlings of the wild-type (Ler) and lig mutant grown at 18 or 28°C for the indicated periods after 7 d of culture at 18°C and subjected to RT-PCR analysis. RNA samples were also prepared from the wild-type seedlings grown at 18°C with or without UPR-inducing reagents (100 ng/mL tunicamycin or 1 mM DTT) for the indicated periods after 7 d of culture without these reagents at 18°C. Amplification of ACT2 is shown as a loading control.

(B) and (C) Wild-type (Ler) seedlings were grown at 18°C for 5 d and then treated with 100 ng/mL tunicamycin or 1 mM DTT for 3 d. Experiments for tunicamycin treatment and DTT treatment were separately conducted.

(B) Primary root tips stained with phloroglucinol-HCl for detection of lignin. Bars = 100 µm.

(C) Growth of primary roots during 3 d of culture with or without tunicamycin or DTT. Vertical bars represent se values for eight to 10 seedlings.