@article {Roddy030122, author = {Adam B. Roddy and Todd E. Dawson}, title = {Hydraulic conductance and the maintenance of water balance in flowers}, elocation-id = {030122}, year = {2015}, doi = {10.1101/030122}, publisher = {Cold Spring Harbor Laboratory}, abstract = {The production and maintenance of flowers is critical for successful reproduction in the angiosperms, yet we know little about how flowers remain hydrated under desiccating conditions. Here we quantify the variability in floral hydraulic conductance (Kflower) for a phylogenetically diverse set of 17 species from 10 angiosperm families and relate the variability in Kflower to traits associated with the liquid phase transport of water into and through flowers and traits associated with the vapor phase diffusion of water vapor from floral surfaces. We found that Kflower was coordinated with traits associated with water supply (vein length per area, VLA) and loss (minimum epidermal conductance, gmin), particularly among the magnoliids. Among the monocots and eudicots, Kflower was largely insensitive to variation in VLA, suggesting that the low VLA of these species may require them to rely on other mechanisms of maintaining turgor than continuous supply of water by the xylem. Kflower varied considerably among species, and its reduction among the monocots and eudicots may have relaxed physiological constraints on flowers and allowed floral morphological traits to be more efficiently molded by pollinator selection in these clades.}, URL = {https://www.biorxiv.org/content/early/2015/10/28/030122}, eprint = {https://www.biorxiv.org/content/early/2015/10/28/030122.full.pdf}, journal = {bioRxiv} }