Plant root exudation under drought: implications for ecosystem functioning

New Phytologist, Journal Year: 2019, Volume and Issue: 225(5), P. 1899 - 1905

Published: Oct. 1, 2019

Root exudates are a pathway for plant-microbial communication and play key role in ecosystem response to environmental change. Here, we collate recent evidence that shows plants of different growth strategies differ their root exudation, can select beneficial soil microbial communities, drought affects the quantity quality exudation. We use this argue central involvement plant propose framework understanding how influence form function during after drought. Specifically, fast-growing modify recruit microbes facilitate regrowth drought, with cascading impacts on abundance functioning. identify outstanding questions methodological challenges need be addressed advance solidify our comprehension importance

Language: Английский

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Soil Rather Than Xylem Vulnerability Controls Stomatal Response to Drought

Trends in Plant Science, Journal Year: 2020, Volume and Issue: 25(9), P. 868 - 880

Published: May 3, 2020

There is an increasing need for mechanistic and predictive models of transpiration stomatal response to drought soil water availability. It has been hypothesized that regulation predictable based on plant hydraulics.The current trend towards a greater consideration hydraulics in earth system science emphasizes xylem vulnerability, neglecting the explicit role root importance hydraulic conductivity status well accepted, but difficult measure.There evidence plants adapt their roots as vicinity, rhizosphere, match conditions atmospheric demand, contributing transpiration. The linking stomata vulnerability. Using soil–plant model, we show vulnerability does not trigger closure medium-wet dry soils propose loss primary driver closure. This finding two key implications: cannot be derived from traits only related soil–root way; interface with soil, are regions can alter efficiently limitations. We conclude connecting below- aboveground necessary fully comprehend responses drought. Stomatal controls most carbon acquisition and, thus, terrestrial productivity at global scale. also regulates fluxes atmosphere through plants. While hydrological cycle, its estimates suffer large uncertainty, spanning 35–80% evapotranspiration [1.Coenders-Gerrits A.M.J. et al.Uncertainties estimates.Nature. 2014; 506: E1-E2Crossref PubMed Scopus (134) Google Scholar, 2.Jasechko S. al.Terrestrial dominated by transpiration.Nature. 2013; 496: 347-350Crossref (764) 3.Schlesinger W.H. Jasechko Transpiration cycle.Agric. For. Meteorol. 189–190: 115-117Crossref (533) Scholar]. uncertainty arises difficulty estimating conductance, particular under stress. Stomata present all land features vascular content Earth. Their function thought prevent cavitation [4.Brodribb T.J. al.Xylem stomata, coordinated time space.Plant Cell Environ. 2017; 40: 872-880Crossref (74) requires respond potential. Two main mechanisms have demonstrated: passive mechanism induced connection between epidermal guard cells; active production hormones, such abscisic acid (ABA) [5.Brodribb McAdam S.A.M. Evolution content.Plant Physiol. 174: 639-649Crossref (105) Sensitivity hormonal signals differs species results varying degrees iso- anisohydricity; these definitions indicate capacity regulate conductance maintain constant (isohydricity) or less (anisohydricity) leaf potential [6.Tardieu F. Davies W.J. Integration chemical signalling control droughted plants.Plant 1993; 16: 341-349Crossref (400) Existing either optimization principles [7.Cowan I.R. Farquhar G.D. relation metabolism environment.Symp. Soc. Exp. Biol. 1977; 31: 471-505PubMed 8.Sperry J.S. al.Pragmatic theory predicts climatic deficits.New Phytol. 2016; 212: 577-589Crossref (131) 9.Wolf A. al.Optimal behavior competition risk impairment.PNAS. 113: E7222-E7230Crossref (144) Scholar] description cell dynamics [10.Buckley T.N. al.A hydromechanical biochemical model conductance.Plant 2003; 26: 1767-1785Crossref (264) Scholar,11.Buckley al.Simple process model: cross-validation against sap flux data.Plant 2012; 35: 1647-1662Crossref (61) Despite great progress [12.Buckley Modeling 572-582Crossref (95) Scholar,13.Mencuccini M. al.Modelling plants: tissues biosphere.New 2019; 0Google Scholar], how drying impacts remains unclear existing empirical [14.Hochberg U. al.Iso/Anisohydry: plant–environment interaction rather than simple trait.Trends Plant Sci. 2018; 23: 112-120Abstract Full Text PDF (184) overestimate during [15.Anderegg W.R.L. al.Plant improves prediction models.PLoS One. 12e0185481Crossref (49) An intriguing hypothesis prevents exceeding supply determined [8.Sperry To accomplish this function, should change (i.e., ∂E∂ψleaf) (see Table 1 definition terms used article). Sperry Love [16.Sperry D.M. What tell us about climate-change droughts.New 2015; 207: 14-27Crossref (258) argued that, view around conductivities area adsorbing roots, it pragmatic assume 'root investment just sufficient approach limit'. Behind assumption, there adjust architecture properties (e.g., texture). follows, authors, cavitation, drying, limits triggers However, were found close much before cavitates; is, which 50% (ψgs50) negative loses (ψx50) follows ψx50 informative predicting closure.Table 1Summary Terms Used ArticleTermDefinitionUnit measurementETranspiration flowm3 s–1gGravitational accelerationm s–2HWater per weight (water head)mhSoil matric potentialmKHydraulic conductancem3 s–1 MPa–1kHydraulic conductivitym s–1KrootRoot conductancecm3 hPa–1ksatSaturated s–1ksoilSoil s–1KxAboveground MPa–1LRoot lengthmqFlux densitym3m–2 s–1ρWater densitykg m–3r0Root radiusmrbRhizosphere radiusmSeSaturation index–SleafDerivative given potentialm3 MPa–1θVolumetric contentm3m–3ψWater volume pressure)MPaψgs50Water 50%MPaψH50Water conductivityMPaψleafLeaf potentialMPaψleaf,predawnPredawn potentialMPaψs50Water conductivityMPaψsoilBulk potentialMpaψx50Water maximal conductivityMPa Open table new tab Here, claim conductivity, more embolism, constraint ψgs50 traits, maximum [17.Henry C. safety-efficiency trade-off constrains dehydration.Nat. Commun. 10: 1-9Crossref (79) ψx50, depends hydraulics. In particular, when drops rapidly increase support opinion data literature covering different flow across (Figure 1, Key Figure). Water flows soil–plant–atmosphere continuum driven gradient potential, rate pathways. set short timescale, regulated opening closing. components variable: vessels stems, leaves cavitate lose potentials ranging –1 –8 MPa [18.Brodersen C.R. al.Functional time.Annu. Rev. 70: 407-433Crossref Scholar,19.Tyree M.T. Vulnerability embolism.Annu. Mol. 1989; 19-36Crossref (here referred radial pathway) decreases anatomical development due suberization [20.Steudle E. Peterson C.A. How get roots?.J. Bot. 1998; 49: 775-788Google formation Casparian bands [21.Zimmermann H.M. al.Chemical composition apoplastic transport barriers corn (Zea mays L.).Planta. 2000; 210: 302-311Crossref (142) Scholar]; reversibly aquaporin (AQP) expression [22.Rodríguez-Gamir J. al.Aquaporin Pinus radiata stress.Plant 42: 717-729Crossref (37) Scholar,23.Caldeira C.F. al.Circadian rhythms growth enhanced improve performance.Nat. 5: 5365Crossref (108) root–soil variable expected decrease shrink contact [24.Carminati al.Do mind gap?.Plant Soil. 367: 651-661Crossref (69) Root hairs contribute matrix [25.Carminati al.Root enable high rates soils.New 216: 771-781Crossref (78) they might break tensile force low potentials. arguably region greatest strongly types. Soil dramatically unsaturated cross-sectional higher tortuosity flowpaths. One important characteristic (increase decrease) instantaneous. means contrast other losses plant, usually reversible upon rehydration. A remarkable exception reversibility where root-secreted mucilage causes strong hysteresis rhizosphere [26.Carminati al.Dynamics rhizosphere.Plant 2010; 332: 163-176Crossref (257) Figure 2A illustrates typical curves types compares them 40 deciduous evergreen [27.Kröber W. al.Linking economics spectrum—a cross-species study 39 broadleaved subtropical tree species.PLoS ONE. 9e109211Crossref (36) range (~0.02–1.5 MPa), differ five orders magnitude, dropping (units discussed Box SI2 supplemental information online). ksoil (cm s–1) decreasing (MPa) geometry single root, density q toward surface, cause nonlinearly surface. These gradients calculated solving equation surface [28.Schroeder T. al.Effect local drop using three-dimensional uptake model.Vadose Zone 2008; 7: 1089-1098Crossref (40) (Box 1). For (7–10–7 cm s–1), bulk negligible wet conductive soils, becomes increasingly steeper 2b). Specifically, each type critical (and relative content) beyond very values faster reaction min h [29.Vico G. al.Effects delays gas exchange intermittent light regimes.New 2011; 192: 640-652Crossref (100) Scholar,30.Katul describe effects CO2 photosynthesis transpiration.Ann. 105: 431-442Crossref (219) Scholar]) 2C). reached hour largely varies ranges –0.1 –1.45 MPa. threshold value –1.2 MPa) would fail promptly protect soils. Therefore, evolution, must developed efficient fast reduction adapting type.Box 1Soil–Plant Hydraulic ModelWe provides xylem, steady-state equalize leaves. Other researchers similar approaches represent (supply function) Scholar].Water ψ (MPa), E (m3 conductance's (Kroot Kx) (ksoil) series. Under steady-rate represented Equation I:q=−ksoilψmρg∂ψ∂r,[I] (m (Pa), ρ density, g gravitational acceleration, r coordinate (m) [50.Gardner W.R. Dynamic aspects availability plants.Soil 1960; 89: 63-73Crossref (582) nonlinear ψm 1A text). Assuming uniform distribution along system, according II:qr0=E2πr0L,[II] r0 radius L length roots. length. Kirchhoff transformation, I solved find ψsr ψsoil SI1 online).In III:E=−Krootψx,r−ψsr.[III] III collar ψx, Kroot MPa–1), conductance. simplicity, here constant, assumption easily replaced complex relation, once known.The IV:E=−Kxψψleaf−ψx,r,[IV] ψleaf Kx MPa–1) Cavitation included describing dependency V:Kxψ=Krootψψ0x−τx,[V] nonlimiting assumed. Equations [IV], [V] (Equation S5 online) yields ψleaf. known. Solving equations 1) gives relationship (cm3 3A ). Presenting E(ψsoil,ψleaf) fundamental insights into reconciles views physiologists 3B) scientists 3C) relations. represents physically possible states plant. When equal, no drive null. soil), linear starts deviate because Whereas, dries out, already moderate conductivity. Xylem embolism determines shape while belowground processes (namely length) (examples shown S1 At any deviates define stress onset limit (SOL), divides zones (red line 3A). SOL 2) point slope E(ψleaf,ψsoil) ψsoil, Sleaf=∂E∂ψleafψsoil, reaches 80% value. zone (green 3A), neither nor subject reductions (in brown generates region, whereas slight Note transition continuous.Box 2Onset Nonlinearity Definition Critical Potential ψs50We trajectory text), separates E(ψleaf) parts: SOL. calculate iso-potential I:Sleafψleafψsoil=∂E∂ψleafψsoil.[I] Sleaf occurs = null-transpiration called Sleaf, max(ψsoil). ratio Sleaf. consider significantly small transpiration, shown, instance II:SleafψleafψsoilSleaf,maxψsoil<80%.[II] arbitrary, taking 70% 90% little sensitivity SOL.ψH50 defined ψs50, ψs50 up Emax sustained. corresponds (not constrained stress). flow, III):ϕs50=12Emax2πr0Lr02−r0rb2lnrb/r0rb2−r02,[III] S3 online, assuming infinitely negative, so null, Emax. obtained S2 doing so, obtain Emax/2 length, factors conductance) micrometeorological intensity, vapor pressure deficit, wind). ψH50 3 shows exemplary (E,ψsoil) (E,ψleaf) planes. From perspective displays universal Scholar,31.Rodriguez-Dominguez C.M. Brodribb Declining drives olive stress.New 2020; 225: 126-134Crossref (73) 3B), consistent well-accepted observations [32.Gardner Ehlig influence plants.J. Geophys. Res. 1963; 68: 5719-5724Crossref Given marked nonlinearity E(ψsoil,ψleaf), optimal strategy undergoing approached able sense ∂ψleaf∂E. enables independently environmental known thus outstanding question.

Language: Английский

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Multifunctional Flexible Humidity Sensor Systems Towards Noncontact Wearable Electronics

Nano-Micro Letters, Journal Year: 2022, Volume and Issue: 14(1)

Published: July 22, 2022

In the past decade, global industry and research attentions on intelligent skin-like electronics have boosted their applications in diverse fields including human healthcare, Internet of Things, human-machine interfaces, artificial intelligence soft robotics. Among them, flexible humidity sensors play a vital role noncontact measurements relying unique property rapid response to change. This work presents an overview recent advances using various active functional materials for contactless monitoring. Four categories are highlighted based resistive, capacitive, impedance-type voltage-type working mechanisms. Furthermore, typical strategies chemical doping, structural design Joule heating introduced enhance performance sensors. Drawing perception capability, human/plant healthcare management, interactions as well integrated sensor-based feedback systems presented. The burgeoning innovations this field will benefit society, especially during COVID-19 epidemic, where cross-infection should be averted sensation is highly desired.

Language: Английский

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Extreme heat increases stomatal conductance and drought‐induced mortality risk in vulnerable plant species

Global Change Biology, Journal Year: 2021, Volume and Issue: 28(3), P. 1133 - 1146

Published: Nov. 6, 2021

Tree mortality during global-change-type drought is usually attributed to xylem dysfunction, but as climate change increases the frequency of extreme heat events, it necessary better understand interactive role stress. We hypothesized that some drought-stressed plants paradoxically open stomata in heatwaves prevent leaves from critically overheating. experimentally imposed (>40°C) and stress onto 20 broadleaf evergreen tree/shrub species a glasshouse study. Most well-watered avoided lethal overheating, exacerbated thermal damage heatwaves. Thermal safety margins (TSM) quantifying difference between leaf surface temperature critical temperature, where photosynthesis disrupted, identified vulnerability Several mechanisms contributed high tolerance avoidance damaging temperatures-small size, low osmotic potential, mass per area (i.e., thick, dense leaves), transpirational capacity, access water. Water-stressed had smaller TSM, greater crown dieback, fundamentally different stomatal heatwave response relative plants. On average, closed decreased conductance (gs ) heatwave, droughted did not. Plant with gs , either due isohydric behavior under water deficit or inherently opened increased temperatures. The current paradigm maintains close before hydraulic thresholds are surpassed, our results suggest may dramatically increase (over sixfold increases) even past their turgor loss point. By actively increasing at temperatures, can be driven toward more rapidly than has been previously recognized. inclusion TSM responses could improve ability predict tree future droughts.

Language: Английский

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Into the Shadows and Back into Sunlight: Photosynthesis in Fluctuating Light

Annual Review of Plant Biology, Journal Year: 2022, Volume and Issue: 73(1), P. 617 - 648

Published: May 20, 2022

Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and leaf CO 2 assimilation ( A) have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, modern crop canopies several layers, light rarely constant, majority leaves experience marked fluctuations throughout day. It takes minutes photosynthesis to regain efficiency both sun-shade shade-sun transitions, costing a calculated 10–40% assimilation. Transgenic manipulations accelerate adjustment transitions already shown substantial productivity increase field trials. Here, we explore means these adjustments minimize losses through transgenic manipulation, gene editing, exploitation natural variation. Measurement andanalysis are explained. Factors limiting speeds how they could be modified effect improved reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, stomatal responses.

Language: Английский

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Effects of Heavy Metals on Stomata in Plants: A Review

International Journal of Molecular Sciences, Journal Year: 2023, Volume and Issue: 24(11), P. 9302 - 9302

Published: May 26, 2023

Stomata are one of the important structures for plants to alleviate metal stress and improve plant resistance. Therefore, a study on effects mechanisms heavy toxicity stomata is indispensable in clarifying adaptation mechanism metals. With rapid pace industrialization urbanization, pollution has been an environmental issue global concern. Stomata, special physiological structure plants, play role maintaining ecological functions. Recent studies have shown that metals can affect function stomata, leading changes physiology ecology. However, although scientific community accumulated some data systematic understanding remains limited. this review, we present sources migration pathways analyze systematically responses exposure, summarize current stomata. Finally, future research perspectives identified. This paper serve as reference assessment protection resources.

Language: Английский

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Green Synthesized Metal Oxide Nanoparticles Mediate Growth Regulation and Physiology of Crop Plants under Drought Stress

Plants, Journal Year: 2021, Volume and Issue: 10(8), P. 1730 - 1730

Published: Aug. 21, 2021

Metal oxide nanoparticles (MONPs) are regarded as critical tools for overcoming ongoing and prospective crop productivity challenges. MONPs with distinct physiochemical characteristics boost production resistance to abiotic stresses such drought. They have recently been used improve plant growth, physiology, yield of a variety crops grown in drought-stressed settings. Additionally, they mitigate drought-induced reactive oxygen species (ROS) through the aggregation osmolytes, which results enhanced osmotic adaptation water balance. These roles based on their physicochemical biological features, foliar application method, applied concentrations. In this review, we focused three important metal that widely agriculture: titanium dioxide (TiO2), zinc (ZnO), iron (Fe3O4). The impacts various forms, dosages growth development under drought stress summarized discussed. Overall, review will contribute our present understanding MONPs’ effects plants alleviating plants.

Language: Английский

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Climate and functional traits jointly mediate tree water‐use strategies

New Phytologist, Journal Year: 2021, Volume and Issue: 231(2), P. 617 - 630

Published: April 24, 2021

Tree water use is central to plant function and ecosystem fluxes. However, it still unknown how organ-level water-relations traits are coordinated determine whole-tree water-use strategies in response drought, whether this coordination depends on climate. Here we used a global sap flow database (SAPFLUXNET) study the of use, terms canopy conductance (G), vapour pressure deficit (VPD) soil content (SWC) for 142 tree species. We investigated individual effect six (vulnerability embolism, Huber value, hydraulic conductivity, turgor-loss point, rooting depth leaf size) parameters, also accounting height climate (mean annual precipitation, MAP). Reference G its sensitivity VPD were tightly with rather than MAP. Species efficient xylem transport had higher but VPD. Moreover, found that angiosperms reference did gymnosperms. Our results highlight need consider trait integration reveal complications challenges defining single, whole-plant resource spectrum ranging from 'acquisitive' 'conservative'.

Language: Английский

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Mild water and salt stress improve water use efficiency by decreasing stomatal conductance via osmotic adjustment in field maize

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 805, P. 150364 - 150364

Published: Sept. 16, 2021

Language: Английский

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A balancing act: how plants integrate nitrogen and water signals

Journal of Experimental Botany, Journal Year: 2020, Volume and Issue: 71(15), P. 4442 - 4451

Published: Jan. 24, 2020

Abstract Nitrogen (N) and water (W) are crucial inputs for plant survival as well costly resources agriculture. Given their importance, the molecular mechanisms that plants rely on to signal changes in either N or W status have been under intense scrutiny. However, how sense respond combination of signals at level has received scant attention. The purpose this review is shed light what currently known about responses impacted by status. We classic studies which detail combinations both synergistic antagonistic effects key traits, such root architecture stomatal aperture. Recent interactions show mutations genes involved metabolism affect drought responses, vice versa. Specifically, perturbing signaling may lead drought-responsive gene expression programs, supported a meta-analysis we conduct available transcriptomic data. Additionally, cite combinatorial transcriptional might drive crop phenotypes. Through these insights, suggest research strategies could help develop crops adapted marginal soils depleted W, an important task face climate change.

Language: Английский

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