Figure 4.

Freeze-fracture cryo-SEM images of intrusive vein xylem recovery from deformation during rehydration. HI index scores are given for each conduit. In a leaf initially at −3.5 MPa and frozen after 20 s of hydration (A and B), the degree of recovery varies between different intrusive veins from no apparent recovery (A) with shrunken mesophyll to almost full recovery (B) with turgid mesophyll. In a leaf hydrated from −3.4 MPa for 120 s, recovery in conduit shape and mesophyll turgor is uniform (C and D). The expected equilibrium water potentials, had the leaves come to internal equilibrium rather than been frozen, were −3 MPa (A and B) and −1.4 MPa (C and D).