Interplay between vessel element development and frequency of cambial cell divisions in broadleaved trees

The study reveals a significant relationship between the development of vessel elements and a reduction in the frequency of periclinal cell divisions.

The relationship between divisional activity, the pattern of cell divisions, interactions between cambial initials, mother cells, and chosen cell types differentiating into secondary xylem remains an intriguing and largely undiscovered area. In the study we analysed the relation between vessel element development and frequency of periclinal cell divisions in the vascular cambium. Juvenile wood of temperate climate tree species differing in wood porosity type was used. Transverse sections of collected plant material were obtained, and analysed using bright field, and epifluorescence microscopy. We showed that the presence of vessel elements is related to a reduction in the number of periclinal cell divisions in radial cell files in which vessel elements were formed. With consideration for assumptions arising from the newly proposed tension stress hypothesis, we speculate that conditions enabling the enlargement of vessel elements by intrusive growth (exceeding the threshold value of radial tensile stress resulting in the separation of periclinal walls of neighbouring cells and the creation of microspaces between them) may modify the stress pattern in the area of their formation. This could lead to a change in the frequency of periclinal cell divisions within affected radial files.