Hydraulic conductance and the maintenance of water balance in flowers

Abstract

Flowers face desiccating conditions, yet little is known about their ability to transport water. We quantified variability in floral hydraulic conductance (Kflower ) for 20 species from 10 families and related it to traits hypothesized to be associated with liquid and vapour phase water transport. Basal angiosperm flowers had trait values associated with higher water and carbon costs than monocot and eudicot flowers. Kflower was coordinated with water supply (vein length per area, VLA) and loss (minimum epidermal conductance, gmin ) traits among the magnoliids, but was insensitive to variation in these traits among the monocots and eudicots. Phylogenetic independent contrast (PIC) correlations revealed that few traits had undergone coordinated evolution. However, VLA and the desiccation time (Tdes ), the quotient of water content and gmin , had significant trait and PIC correlations. The near absence of stomata from monocot and eudicot flowers may have been critical in minimizing water loss rates among these clades. Early divergent, basal angiosperm flowers maintain higher Kflower because of traits associated with high rates water loss and water supply, while monocot and eudicot flowers employ a more conservative strategy of limiting water loss and may rely on stored water to maintain turgor and delay desiccation.

Vapour pressure deficit control in relation to water transport and water productivity in greenhouse tomato production during summer

“…According to physical principles and experimental evidence, regulating the atmospheric moisture was an efficient solution for suppressing the excess driving force. The mass of plant water transport through the plant must balance the transpiration losses from the leaves, which can be expressed as follows1516:…”

Water relations of Calycanthus flowers: Hydraulic conductance, capacitance, and embolism resistance

“…For example, the water costs of flowers can limit flower size and impede leaf function (Galen, ; Galen, Sherry, & Carroll, ; Lambrecht, ; Lambrecht & Dawson, ; Teixido & Valladares, , ). This requirement of maintaining water balance has led to coordinated shifts in hydraulic traits that vary systematically across the angiosperm phylogeny (Roddy, Brodersen, & Dawson, ) and with other pollination traits, such as floral lifespan (Zhang et al, ).…”

Floral Mass per Area and Water Maintenance Traits Are Correlated with Floral Longevity in Paphiopedilum (Orchidaceae)

“…Flower maintenance may require a considerable amount of water (Roddy and Dawson, 2012) and, under dry conditions, those plants can lose more water from their flowers than from the leaves (Lambrecht, 2013). Therefore, understanding the physiological mechanisms of floral water transport and water relations may provide new insights into the evolution of flowers (Galen, 2000; Chapotin et al, 2003; Feild et al, 2009a,b; Roddy et al, 2016). Even though water has an essential role throughout the floral lifespan, few studies have focused on water relations in flowers (Feild et al, 2009b; Lambrecht et al, 2011; Roddy et al, 2016).…”

“…Therefore, understanding the physiological mechanisms of floral water transport and water relations may provide new insights into the evolution of flowers (Galen, 2000; Chapotin et al, 2003; Feild et al, 2009a,b; Roddy et al, 2016). Even though water has an essential role throughout the floral lifespan, few studies have focused on water relations in flowers (Feild et al, 2009b; Lambrecht et al, 2011; Roddy et al, 2016). Contrasting results in different species have indicated that some flowers are phloem-hydrated (Trolinder et al, 1993; Chapotin et al, 2003).…”