Tracheary Element Differentiation and Secondary Cell-wall Formation in Cell Cultures of Coniferous Gymnosperms*

Tracheary element differentiation and secondary cell-wall formation have been studied in cell cultures of coniferous gymnosperms. Factors that influence tracheary element differentiation are (i) the sucrose concentration in the media, (ii) the concentration of nutrients in the media, (iii) temperature and light, and (iv) the types and concentrations of phytohormones in the media. There are advantages and disadvantages in using cell cultures for studying tracheary element differentiation and secondary cell-wall formation, but in combination with in planta studies the cell culture approach is very useful for advancing our understanding of these processes.