Embolism resistance as a key mechanism to understand adaptive plant strategies

Lens, Frédéric; Tixier, Aude; Cochard, Hervé; Sperry, John S.; Jansen, Steven; Herbette, Stéphane

doi:10.1016/j.pbi.2013.02.005

Cited by 192 publications

(184 citation statements)

References 62 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…This is a particularly important shortcoming considering that pit and pit‐membrane ultrastructure varies widely across species, even within a single genus (Lens et al. 2011, 2013). However, our estimates of xylem‐specific conductance in petioles are correlated with measured xylem‐specific conductance in branches ( r 2 = 0.48; P < 0.001) (Gleason et al.…”

Section: Discussionmentioning

confidence: 99%

Weak coordination among petiole, leaf, vein, and gas‐exchange traits across Australian angiosperm species and its possible implications

Gleason

Blackman

Chang

et al. 2015

Ecology and Evolution

View full text Add to dashboard Cite

Close coordination between leaf gas exchange and maximal hydraulic supply has been reported across diverse plant life forms. However, it has also been suggested that this relationship may become weak or break down completely within the angiosperms. We examined coordination between hydraulic, leaf vein, and gas‐exchange traits across a diverse group of 35 evergreen Australian angiosperms, spanning a large range in leaf structure and habitat. Leaf‐specific conductance was calculated from petiole vessel anatomy and was also measured directly using the rehydration technique. Leaf vein density (thought to be a determinant of gas exchange rate), maximal stomatal conductance, and net CO 2 assimilation rate were also measured for most species (n = 19–35). Vein density was not correlated with leaf‐specific conductance (either calculated or measured), stomatal conductance, nor maximal net CO 2 assimilation, with r 2 values ranging from 0.00 to 0.11, P values from 0.909 to 0.102, and n values from 19 to 35 in all cases. Leaf‐specific conductance calculated from petiole anatomy was weakly correlated with maximal stomatal conductance (r 2 = 0.16; P = 0.022; n = 32), whereas the direct measurement of leaf‐specific conductance was weakly correlated with net maximal CO 2 assimilation (r 2 = 0.21; P = 0.005; n = 35). Calculated leaf‐specific conductance, xylem ultrastructure, and leaf vein density do not appear to be reliable proxy traits for assessing differences in rates of gas exchange or growth across diverse sets of evergreen angiosperms.

show abstract

Section: Discussionmentioning

confidence: 99%

Weak coordination among petiole, leaf, vein, and gas‐exchange traits across Australian angiosperm species and its possible implications

Gleason

Blackman

Chang

et al. 2015

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…Consistent with this theory, we observed only functional primary xylem with helical to scalariform secondary thickenings in the smallest boundary and intrusive veins of red oak. The destruction of protoxylem has been hypothesized to provide sites where metaxylem pits (once connected to protoxylem) now contact gas-filled spaces (Lens et al, 2013). That high vein orders lack such exposure may explain their apparent resilience to cavitation versus lower orders and why embolism spreads in leaves by propagation from low vein orders to high .…”

Section: Sensitivity Of the Modelmentioning

confidence: 99%

“…The most probable origin of such nuclei is thought to be gas bubbles pulled through a pit membrane from an adjacent, gas-filled conduit (Lens et al, 2013), and many studies have focused on the formation and propagation by air seeding of embolism as a key determinant of plant performance (Choat et al, 2012). However, negative pressures in xylem conduits can affect xylem function in other ways.…”

mentioning

confidence: 99%

Reversible Leaf Xylem Collapse: A Potential “Circuit Breaker” against Cavitation

et al. 2016

View full text Add to dashboard Cite

We report a novel form of xylem dysfunction in angiosperms: reversible collapse of the xylem conduits of the smallest vein orders that demarcate and intrusively irrigate the areoles of red oak (Quercus rubra) leaves. Cryo-scanning electron microscopy revealed gradual increases in collapse from approximately 22 MPa down to 23 MPa, saturating thereafter (to 24 MPa). Over this range, cavitation remained negligible in these veins. Imaging of rehydration experiments showed spatially variable recovery from collapse within 20 s and complete recovery after 2 min. More broadly, the patterns of deformation induced by desiccation in both mesophyll and xylem suggest that cell wall collapse is unlikely to depend solely on individual wall properties, as mechanical constraints imposed by neighbors appear to be important. From the perspective of equilibrium leaf water potentials, petioles, whose vessels extend into the major veins, showed a vulnerability to cavitation that overlapped in the water potential domain with both minor vein collapse and buckling (turgor loss) of the living cells. However, models of transpiration transients showed that minor vein collapse and mesophyll capacitance could effectively buffer major veins from cavitation over time scales relevant to the rectification of stomatal wrong-way responses. We suggest that, for angiosperms, whose subsidiary cells give up large volumes to allow large stomatal apertures at the cost of potentially large wrong-way responses, vein collapse could make an important contribution to these plants' ability to transpire near the brink of cavitation-inducing water potentials.Terrestrial photosynthesis is inextricably linked with water loss. Plants expose hydrated cells to the atmosphere to obtain CO 2 , with evaporation an inevitable consequence. Vascular plants meet this challenge by replacing water lost via transpiration with water pulled from the soil. What allows this is the xylem: a system of stiff-walled conduits capable of remaining water filled at negative pressures low enough to extract water from micrometer-to nanometer-scale soil capillaries and to drive flow through the 10-to 100-mm-diameter xylem conduits that extend from the roots to the leaves (Tyree and Zimmermann, 2002). To deliver water at rates equal to transpiration, the pressure in the xylem must fall far below the vapor pressure of water, such that water transport through the xylem occurs in a metastable state (i.e. at kinetic, but not thermodynamic, equilibrium) and thus at risk of cavitation (Stroock et al., 2014). How many plants seemingly operate with little to no safety margin against cavitation Brodribb and Holbrook, 2004;Meinzer et al., 2009;Choat et al., 2012) remains an important and unsolved question.Cavitation occurs when metastable liquid water is replaced by water vapor due to the expansion of a gas bubble nucleus, forming an embolism or air blockage: embolism disrupts water transport because tensions cannot be transmitted through gas. The most probable origin of such nuclei is thought to be g...

show abstract

“…However, the processes involved in the ability of the perennial herbaceous plant to survive and recover after tissue dehydration require better characterisation (Craine 2013;Hoover et al 2014). In particular, the hydraulic thresholds of mortality in perennial grasses should be investigated with recent methodological developments that allow the measurement of vulnerability to cavitation associated with drought survival in trees (McDowell et al 2008;Reich 2014) (Lens et al 2013). Over the last decade, methods to measure dehydration tolerance in forage crop species have evolved and these have been extended to, Poa bulbosa L. , and modified to compare the dehydration tolerance of perennial grasses with barley (Volaire 2003) and wheats of both annual and perennial habit (Larkin et al 2014).…”

Section: Dehydration Tolerance To Improve Survival Of Droughtmentioning

confidence: 99%

Plant drought survival under climate change and strategies to improve perennial grasses. A review

Norton¹,

Malinowski²,

Volaire

2016

Agron. Sustain. Dev.

View full text Add to dashboard Cite

The three cool-season perennial forage grasses cocksfoot/orchardgrass, Dactylis glomerata L., tall fescue, Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh., and phalaris/harding grass, Phalaris aquatica L., are of major economic and ecological importance in regions with summer-dry environments. This review considers the constraints that these species are likely to experience under current and predicted increase of droughts due to climate change scenarios in south-eastern Australia, the southern Great Plains of USA and the Western Mediterranean Basin. The review identifies research required to maximise the development and use of C3 cool-season grasses with enhanced resilience to drought while considering the concern of some regulators that these grasses may be potential weeds. The state of knowledge of factors influencing plant drought survival and therefore recovery after stress and long-term persistence is discussed in the light of adaptive strategies. The major research needs identified to enhance traits conferring drought survival include (1) increasing the depth and density of grass root systems to strengthen dehydration avoidance; (2) exploring the biochemical, molecular and hydraulic bases of dehydration tolerance and improving techniques to measure this trait; (3) breaking the trade-off between summer dormancy and forage yield potential and improving understanding of environmental, biochemical and genetic controls over summer dormancy; (4) identifying non-toxic endophyte strains compatible with summer-dormant cultivars of tall fescue to enhance drought survival; and (5) enhancing seed production capability of new cultivars as well as the development of agronomic management packages for promoting stable mixtures combining perennial grasses and legumes. The weed potential of newly introduced summer-dormant cultivars is concluded to be minor. The research directions proposed here should improve pasture grass resilience and forage crop sustainability in Mediterranean and temperate summer-dry environments under the future drier and warmer conditions associated with climate change.

show abstract

Embolism resistance as a key mechanism to understand adaptive plant strategies

Cited by 192 publications

References 62 publications

Weak coordination among petiole, leaf, vein, and gas‐exchange traits across Australian angiosperm species and its possible implications

Weak coordination among petiole, leaf, vein, and gas‐exchange traits across Australian angiosperm species and its possible implications

Reversible Leaf Xylem Collapse: A Potential “Circuit Breaker” against Cavitation

Plant drought survival under climate change and strategies to improve perennial grasses. A review

Contact Info

Product

Resources

About