This cross section of the stem of a soybean seedling shows the early stages in a developmental process that will produce a stem capable of supporting the mature plant. I stained the section with two fluorescent dyes - calcofluor, which binds to cellulose cell walls and fluorescences blue in ultraviolet light and auramine O, which binds to lignin and fluorescences yellow. It's the lignin laid down in cell walls that gives the stem the strength it will need to support the leaves and flower…
1.4k