A new protocol for psychrometric pressure-volume curves of fern gametophytes.

ABSTRACT

PREMISE Pressure-volume curves are a widely used analytical framework to derive several key physiological traits related to plant-water relations, including a species' turgor loss point, osmotic potential at full turgor, and the elasticity of cell walls. We developed a novel protocol, including the preparation and treatment of fern gametophytes, to generate data for pressure-volume curve analyses using thermocouple psychrometry. METHODS AND RESULTS: Gametophytes of the fern species Polystichum lemmonii were grown from spore, harvested, and subjected to a series of drying intervals. We constructed pressure-volume curves using thermocouple psychrometers to calculate gametophyte water potential and a balance to measure relative water loss. CONCLUSIONS: We present the first protocol for fern gametophyte pressure-volume curves that can accurately determine key physiological traits in fern gametophytes such as the turgor loss point and osmotic potential at full turgor.