Figure 4.

Expression analysis of cpp1. (A) RNase protection analysis by using a transcript of cpp1 corresponding to amino acid numbers 757–811 as a probe. The RNA used in this analysis was isolated from uninfected soybean roots (R), leaves (L), callus (C), and nodules harvested 1–21 days after infection by Bradyrhizobium japonicus (N1–N21). (B) In situ hybridization with cpp1 antisense, (C) cpp1 sense, and (D) Gmlbc3 antisense transcripts as probes to cross sections of a 13-day-old soybean nodule. Infected cells (IC), uninfected cells (UIC), and early infection zone (EIZ) are indicated. The silver grains were visualized by epipolarization microscopy through a red filter (B and C) or directly by bright-field microscopy (D). The images were adjusted in Adobe photoshop to enhance the weak red color.