Microscopic distribution of taxanes in freeze-fixed stems of Taxus cuspidata

The overall amount of taxanes was higher in the late summer than in the spring. Also, taxanes' radial distribution was generally found at higher concentration in the phloem, the cambium and lower level in the periderm, the latest-forming xylem, with different taxanes showing several patterns with distinction between seasons, which were considered related to seasonal plant physiological behaviors. In addition, the distribution of baccatin III (BAC) was investigated at the cellular level, which was regarded in specific cells suggesting its transport in the radial and axial directions in the <i>T. cuspidata</i> stem. Characterizing the microscopic distribution of taxanes in the <i>T. cuspidata</i> stem is expected to play a role in the further study of their biosynthesis and <i>in planta</i> behaviors.