Fig. 8

Model for BL-mediated cell wall development in switchgrass suspension cultures. The cell wall components cellulose, hemicellulose, pectin, and lignin are represented as yellow, blue, and green lines, and triangles symbols, respectively. Dynamic changes in cell wall composition and gene expression are represented in black and red squares, respectively. The direction of arrows shows increase (↑), restoration (→), or decrease (↓) in content of the corresponding components. Significant changes in cell wall composition and gene expression at each time point are as follows: at 6 h, a decrease in arabinose/xylose ratio, contents of pectin released by sodium carbonate, and an up-regulation of CESAs involved in primary cell wall synthesis; at 1 day, restored content of arabinose, xylose, and pectin; at 3 days, an increased content of lignin, p-CA and mixed-linkage β-glucan, a reduced ratio of arabinose/xylose, and an up-regulation of CESAs associated with secondary cell wall synthesis; at 7 days, an increased content of xylan, lignin, p-CA and mixed-linkage β-glucan, and restored ratio of arabinose/xylose