Mechanical pressure inhibits vessel development of xylogenic cambial derivatives of beech (Fagus sylvatica L .)

 Segments of standing beech stems (Fagus sylvatica) were put under mechanical pressure from the end of May, in order to investigate the influence of constant external pressure on the development of secondary vascular tissue. After 4 weeks, the new xylem increment was investigated anatomically in cross-sections. The first axial xylem derivatives of the new year’s increment had differentiated into normal vessel elements and fiber-tracheids. Application of the pressure girdle had no effect on fiber-tracheid development, but it inhibited vessel formation. Under pressure, changes in the two dimensional PAGE protein pattern were characterized by the appearance of two new protein species as well as by the absence of one species that occurs under regular growth.