Pressure-volume analyses were done on a half-shrub broom snakeweed (Gutierrezia sarothrae) subjected to different soil water regimes under pot- and field-grown conditions. Under pot and field conditions, water deficit decreased water and osmotic potentials. In the severely droughted pot-grown, osmotic potential at full turgor (?100) decreased by 0.44 MPa due to reduced symplastic volume, the result of a decreased leaf turgid to dry weight (TW/DW) ratio. A reduction of 0.86 MPa in ?100 was observed in the field-grown plants subjected to the first drought cycle, but increased cell wall elasticity occurred in the second drought cycle. The lowered ?100 was attributed to osmotic adjustment and reduced symplastic volume. High cell wall elasticity [...]
