Existence of growth-induced negative pressures in elongating stems

Establish whether growth-induced negative hydrostatic pressure at the center of an elongating cylindrical stem can occur in real plant tissues or is merely an artefact of the saturation assumption in the poromorphoelastic model; characterize the conditions under which such negative pressures would arise or be precluded.

Background

In the steady analysis of a growing cylindrical stem, the model predicts that for sufficiently large radii and limited water supply, pressure near the core could become negative due to hydraulic deficits and tensile forces from the epidermis. This raises a fundamental question about the physical realizability of negative turgor within living tissues under growth-induced conditions.

The authors highlight that this phenomenon depends on modeling assumptions, notably saturation, and acknowledge uncertainty about its existence in vivo, linking the issue to possible mechanisms of cavity formation in stem hollowing.