Time course of GmNAC6 induction by biotic stress signals. A. GmNAC6 is induced by treatment with cell wall-degrading enzymes (CDE). Soybean leaves were infiltrated with CDE, as described in the Methods, for the indicated times. Total RNA was isolated from the infiltrated sectors, and the relative expression of GmNAC6 (NAC6), UPR-specific gene markers (CNX and BiP) and integrated pathway genes (NRP-A, NRP-B, and GST) was determined by quantitative RT-PCR. B. Up-regulation of GmNAC6 by the hypersensitive response. Soybean leaves were inoculated with Pseudomonas syringae patovar tomato (P.st.) for the indicated period of time. The relative expression of GmNAC6, the integrated pathway genes (NRP-A and NRP-B) and pathogenesis-related genes (PR1 and PR4) was determined by quantitative RT-PCR.