Credit: Brookhaven National Laboratory
Cross-sections of wild type (a,c) and transgenic (b,d) aspen stems stained with lignin detection agents. The violet red color in the upper images indicates no dramatic change in total lignin content between the wild type (a) and transgenic (b) plants. The red color staining specific for one particular lignin structural unit shown in the lower images, however, indicates a significantly lower level of this component in the transgenic aspen (d) compared with the wild type (c). These findings suggest that lignin in the transgenic aspen has significantly altered composition and structure.