The Live-Box: a new device for quantifying transpiration kinetics at the whole-plant scale

Abstract

To study plant resistance to drought, we need to be able to continuously monitor various physiological traits, including residual leaf conductance (or residual transpiration), a major functional trait. However, existing methods are partial and destructive. As part of the work carried out by the SUREAU team, a member of the PIAF unit (Physique et physiologie Intégratives de l’Arbre en environnement Fluctuant), we have developed a new device, the Live-Box, to study the response of intact plants to different controlled levels of drought and VPD (vapor pressure deficit). The Live-Box is a homemade, temperature- and relative humidity-controlled box that can accommodate a whole plant. The plant is continuously weighed and monitored by various sensors to measure drought-related physiological traits. After validating the device’s homogeneity and stability, we present the results concerning the residual transpiration of two species: potted poplar (Populus tremula x Populus alba) and Portuguese laurel (Prunus lusitanica) plants. The Live-Box can be used to detect stomatal closure and minimum conductance on a whole plant subjected to drought. In parallel, we can monitor water potential using psychrometric sensors.