Deleted Journal, Journal Year: 2023, Volume and Issue: 26(48), P. 589 - 593
Published: Jan. 1, 2023
Plant Cell & Environment, Journal Year: 2024, Volume and Issue: 47(8), P. 3063 - 3075
Published: April 25, 2024
Abstract Embolism resistance of xylem tissue varies among species and is an important trait related to drought resistance, with anatomical attributes like pit membrane thickness playing role in avoiding embolism spread. Grafted Citrus trees are commonly grown orchards, the rootstock being able affect whole plant. Here, we evaluated how rootstocks vulnerability scion using several rootstock/scion combinations. Scions ‘Tahiti’ acid lime, ‘Hamlin’, ‘Pera’ ‘Valencia’ oranges grafted on a ‘Rangpur’ lime exhibit similar embolism. In field‐grown trees, measurements leaf water potential did not suggest significant formation during dry season, while stomata presented isohydric response declining availability. When orange scions were ‘IAC 1710’ citrandarin, ‘Sunki Tropical’ mandarin or ‘Swingle’ citrumelo rootstocks, variation intervessel was found. The rootstock, which known for its induced thicker membranes scion, resulting higher than other rootstocks. Similarly, citrandarin generated increased highly relevant citriculture.
Language: Английский
Citations
6
New Phytologist, Journal Year: 2022, Volume and Issue: 237(2), P. 374 - 383
Published: Dec. 20, 2022
Chen et al. (2021) reported discrepancies between pneumatic and other methods for measuring embolism vulnerability in plant xylem tissue, leading them to caution against using the method. We show that this discrepancy arises from faulty implementation: failing measure air discharge sufficiently negative water potentials, they under-estimated maximum (ADmax), hence resistance. Embolism identify how dehydrated a stem must become (in potential, P50) cause 50% loss conductivity. Pneumatic require measurements potentials roughly twice as P50. Yet often stopped at magnitudes even less than what showed P50 be, making it mathematically impossible their implementation true Our simulations confirmed premature stopping causes large errors derived P50, accounting discrepancies. Further, literature studies consistent agreement methods. Thus, al.'s results are invalid, should not be taken undermine confidence measurements. recommend best practices, including 'Pneumatron' automated measurements, prevent of make fast, replicable, accurate. Drought-induced is potentially important mechanism mortality during severe drought natural agricultural systems (McDowell al., 2008; Brodersen & McElrone, 2013; Choat 2018), with debate on whether embolisms primary causal mechanism, or an associated side effect, tree (Körner, 2019). This has stimulated research efforts understand plants embolism, which depend accurate measurement traits related hydraulic failure transport system. The parameters measured quantified (or P88), potential lose 88%) conductivity dehydration process (Sperry 2002; Meinzer 2009). In recent paper entitled 'Quantifying tropical trees lianas five methods: can explained by structural traits?', (hereinafter simply al.) compared estimate terms curves obtained recently-developed rapid method (Pereira 2016) comparison bench-top Tyree, 1988), optical (Brodribb 2017) X-ray-computed microtomography (microCT; Cochard 2015). They argue method, quantifies relative increasing volume discharged embolized regions branch's (relative amount discharged, ADmax) branch laboratory, underestimates therefore Comparisons among advancing science, but done carefully there differences methodological assumptions practices create apparent results, actually artefacts 2016, 2020a,b, 2021; Zhang 2018; Jansen 2020; Sergent 2020). Here, we vs outlier all have used it; offer evidence anomalous result likely artefact caused inadequate others who applied Since otherwise generally methods, conclude fact offers effective reliable way across angiosperm species. key problem evident own data, suggests incorrect determination step al's fig. 1(d) (reproduced here Fig. 1) shows did (blue points line achieve discharge. ADmax, end sequence approached when values decline levels corresponding 100% Correct estimation ADmax necessary accurately normalize percent (PAD), vertical axis graph 1. Good practice thus normally continue until supports conclusion been reached 2016; Trabi 2021). If estimates too low, (PAD = AD/ADmax) will consistently high, point soon, small (i.e. insufficiently negative), underestimated. data (Fig. precisely this; indeed, were some cases extreme underestimates, reach value seeking quantify. estimated example represented blue dashed 1 forced substantially red line. analysis demonstrates would possible give pneumatically-derived estimate, regardless status branches being details issues may two independent lines support inference (from underestimate First, conduct simulation based new dataset variation its magnitude. use could arise experiment soon (as curve 1). Second, present analysis, compiled our compares deviation showing literature. P88 seven published in-review (Supporting Information Table S1). added these datasets eight species seasonal Amazon forests Brazil, both described S2 S1. conducted kinds analyses: first, test sensitivity pneumatically (P50, P88) ADmax; second, multiple different studies. All analyses performed R software (v.3.5.1; Core Team, Forest (Table S2; S1) started ADmax.ref, ΨPADmax.ref P50.ref reference values, 'best' discharge, each (according presented supplement). then quantify sensitive artificially reduced ΨPADmax lower ADmax.ref (taken purposes 'true' values). simulated several species, repeatedly recomputing PAD subsets consecutively (and correspondingly potentials). retained least first three most hydrated (least potentials) enough fit S-shaped curve. included model converged cases, particular subset generate because converge due low number points). error ratio P50.simulated : P50.ref, giving one P50.ref. Relative ΨADmax 1.0 indicate where quantification unambiguously early, independently determined definition smaller magnitude (being ADmax), such < (including depicted provide greater still close suspect (because typical symmetric curves, c. ΨADmax, see S2). As increases 1.5 2.0 higher, 'safer' sense suffer underestimation ADmax. index calculating separate (simulated) was lowered. also flag undermeasurement al.), (typically hydraulic). either or, raw available, graphs study (see Where made replicate branches, produces (ΨADmax). case, took conservative approach, taking replicates computing (since idea parameter, indicates this). S1), pneumatic, (hydraulic), injection, optical, flow-centrifuge microCT Because previous gymnosperms difficult manual approach 2020), removed gymnosperm main only data. Also, distinguish Pneumatron device introduced get more reduce variability 2020a). tested null hypothesis regression another indistinguishable slope intercept zero), standardized major (SMA) ANCOVA smart package (v.3.4.8; Warton 2012), categorical variable slopes (interaction structure) elevation (additive linear relationship study. Using type II SMA) minimizes residuals without assuming ordinary squares ANCOVA) apply y-axis (Warton 2006, 2012; Wehr Saleska, 2017). particular, able determine studies, specific (e.g. differed For that, SMA intervals (CI) modelled elevation. When CI overlapped zero, respectively, and/or 2006). addition, calculated Cook's distance order largest (outliers) high leverage models fitted (using squares) might influence given (Cook, 1979). 2. refitted scaled successively systematically magnitude, average, (P50.ref), seen nine (Figs 2, S3). (simulated fraction so no error, means underestimate) (Relative ΨADmax/P50.ref) 2 right summary panel) (with indicating extremely values) rose towards matching (horizontal Fraction 1.0) increased. summarized y xn/(Km + xn) (the generalized Michaelis–Menten model, Km 0.34, n 1.83, Obs Pred2 0.47; P 0.001). varied scatter right, broken out panels plotted (taking ΨADmax) same (red panel). found (three five) (indicating impossible-to-estimate P50). slightly (fraction 2), portion difference factors moderate intrinsic methods). However, fell within cloud points, suggesting stopping. Considering full broad S3) – except study, stands 3a). consistency those far 3b), disagreement (RMSD 2.7 MPa) intercept, had range 3b; six studies' agreed 95% (except Paligi which, though 1, just statistically > 0 S3), (2020), long-vessel (but Pereira 2021), second RMSD (1.57 MPa; 3b). individual (2020) considered outliers according S4). indicated discussion Introduction section regarding mainly early middle phases process, none reaching late stage obtain complete (though note further analysed separately 6, Discussion section). half determining percentage 3c colour code), four 4.5 MPa 6.5 MPa). lesser (indicative sooner) insufficient underestimated (yellowish colours 1; 3c). By contrast, nonpneumatic resistance vessels (frequently −6.5 finding inconsistent comparing updated Brum (2019) 3, almost certainly namely (ADmax) before potentials. supported 2) deviations occur sufficient dehydration, pulls away relationship) many halted short tissue's putative match (which implemented invalid scientific and, significant advance application device, 2020a) makes much easier virtually (even inexperienced users) kind generates internal noise, 4), achievement lack) saturating level directly. allow generally, gymnosperms, previously problematic (it reason focussed cited studies) (Sergent detailed practical advice construction open-source modification distribution anyone), guidance implementing high-quality refer readers (2021). list suggest cautions trusting generally. Given here, however (that finds render artefacts), rather consider sources measurement, do raise much-discussed agree users aware of, review drawing earlier work Guan Yang 2021) references 'best practice' concerns listed are: (1) biased cut supposed vulnerable cutting; (2) systematic uncertainties estimating illustrate whose purportedly exhibits distinct plateaus raising question investigators tell saturation 6 al.); (3) source measurements; (4) vessel shrinkage cracks gas leaks quantities. With regard (1), special susceptibility cutting itself: clarify confusion cut-open conduits intact ones. Conduits open quickly gas-filled extension tube. effectively part sample bias measurement. Indeed, minimum ADmin (at beginning measurement), accounts vessels. proximity facilitate propagation stages (a explanation why P12 spreading samples, available detection whole limited end, exacerbated beyond initial stages, propagates throughout (Choat Hochberg 2016), others, happens long nucleate bubbles adjacent itself induces design, dehydration). user should, any find 3), Regarding (2), ADmax: quite incorrectly illustrated problems dataset), also, careful attention detail, avoidable, other, non-Chen reviewed managed produce methods), Pneumatron, 4). arguing resultant (thereby introducing ambiguity about be) carried report −20 S5, reproduces 6). Putting aside reliability like MPa, S5 here) seems point: S5), −1.58 MPa. Including rescaling curve), calculate −6.32, manuscript −5.38 −5.45 −7.48 microCT). scepticism warranted: −10 outside instruments (ICT electronic psychrometers pressure bomb), observed, extrapolated drying time (parameters shown raises questions extrapolations, nonlinear validated); if real (they rarely literature), bring desiccation-induced destabilization cell interior lipid bilayers, limits tolerable pressures above thereby limiting functioning (Kanduč desiccation subject cracking leakage through tight-fitting hose clamps apparatus. Finally, double plateau S5) hard discern amidst noisy (Chen statistical objective existence plateaus, challenge anyone looking clearly respect salient panel b, c). (between consists while plateau's directly plateau, exists, mismatch observation extrapolation. sceptical really useful, curve, believe especially advent approaches 4b) automatically reached, issue identifying minor future via It keep mind benchmark scaling unique applies uses area pixels, 2017; contrasts conductivity-based resistance, (assuming PLC 0%), AD response decrease zero. Therefore, rely clear temporal normalization. Users good starting (Khmax; state), well defined endpoint stable obtained. (3), air: experimental diffusion kinetics measures extracted embolized, fast movement pit membranes (Jansen 2020b; Avila 2022; Peng 2022), conduit walls slower (Sorz Hietz, 2006; Wang Although mass flow 10 000 times faster liquid, thin nature very (within seconds) (Yang There solid 15 s supporting theoretical basis nonetheless uncertainty next point). (4), shrinking cracks: leaky pith tissue problematic, nonwoody plants, woody measurable (despite risk leaks), connected thence think difficult-to-detect micro-cracks shrinkage-induced contributing correctly implementations warrant continued develops. example, near (Trabi sum, nuances anatomical function under stress fully understood contribute normal focus characterizing vulnerability. experiments (aside identification exhibited per se, comparable negate case checking alternatively, apparatus, 4) assure examination samples after assess signs degraded quality (presence visible cracks, resins, etc.) Beyond issues, is: expect diverse (pneumatic, hydraulic, observations optical) common resistance? Addressing requires consideration mechanistic understanding anatomy biological exactly measured. More work, however, needed flow), affects duration experiments, relates neighbouring 2022). At time, (López While traditional strongly affect include ionic wounding resin latex production), artificial induction clogging over pressure-driven (De Baerdemaeker 2019; Bonetti depends arguably availability sap presence, phase having largely neglected discussions. such, strengths breakdown addressed. sense, helps unveil inside differences, unexplored conclusion, (both mechanisms comparisons deeply flawed produced curves. required put side, experimentalists scientists doubt utility properly experiments. emphasize progress science frequently relies novel address long-standing questions, (especially now augmented apparatus) cost-effective improvements speed ease field settings. falsely well-grounded appear propagate prejudices strengths, weaknesses limitations always assessed, extensive growing assessments foundation US National Science Foundation (NSF) awarded DEB-1754803 MB SRS. RVR RSO fellows Council Scientific Technological Development (CNPq, Brazil). LP SJ acknowledge funding Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, project no. 410768178 457287575). funded GO-AMAZON FAPESP (2013/50533-5) FAPESP-UoM (2014/50332-2) collect Forest. financed Coordenação de Aperfeiçoamento Pessoal Nível Superior Brasil (CAPES) Finance Code 001 PRLB acknowledges UK's Environment grant (NE/V000071/1). MB, SRS led version manuscript. analysis. PRLB, SJ, RSO, RVR, SRS, appointments derive authors contributed writing S1 Vulnerability conductance Forest, FLONA-Tapajós, Pará, Brazil. Example effect contrast S3 induced index, simulations, covary simulation. S4 (calculated observation) identifies pneumatically-estimated along scatterplot (pneumatic) (reference method). Reproduction (annotated) (2021), (quoting caption 'The (ΔVi, μl)' broader standard Studies compare Taxonomic studied Tapajos km 67 LBA area, Fit regression. Please note: Wiley responsible content functionality Supporting supplied authors. Any queries (other missing material) directed New Phytologist Central Office. publisher information content) author article.
Language: Английский
Citations
10
New Phytologist, Journal Year: 2022, Volume and Issue: 233(4), P. 1556 - 1559
Published: Jan. 20, 2022
Like all organisms, plants are heterogeneous porous media, which means that they a collection of solid matter, with plenty open spaces in and around the solids. The vary from nano- to macro-scale openings, enable liquids gasses pass through or them. Most also grow medium (the soil), embedded free flow domain atmosphere), representing soil–plant–atmosphere continuum (Fig. 1). Transport processes within such unsaturated media difficult examine due complex nonlinear nature multiphase interactions between gas, liquid, phases. While liquid phase has received considerable attention research on plant water relations, especially long-distance transport xylem (Venturas et al., 2017), gas is at least equally important omnipresent along entire hydraulic pathway (Gartner 2004). Yet, changes vapour, not only challenging understanding sap, but crucial for fundamental related photosynthesis respiration. Indeed, have been known many years show pneumatic properties, internal structures atmosphere determining key aspects fitness evolution (e.g. Hales, 1727; MacDougal, 1932, 1936). A new series online meetings initiated address questions pneumatics, aim bringing together diverse group scientists world-wide. first meeting, was hosted by Steven Jansen 22 April 2021, explored potential interest measurements, while Norbert Kunert chaired second meeting 29 September broadening scope gas-related biology. Here, we briefly report why needs more attention, how this may facilitate collaboration, discussion communication across subdisciplines biology, aiming broaden researchers' views multiple gases plants. recent were motivated implementation Pneumatron devices, automated tools extracting quantifying plants, their invention created ways studying These instruments initially designed take manual discharge measurements embolism conduits dehydrating tissue (Pereira 2016; Bittencourt 2018). By making measuring steps fast automated, Pneumatrons shown provide easy approach directly resistance 2020a; Trabi 2021). point discussed detail Roman Link (University Würzburg, Germany) highlighted need robust metrological framework comparing mismatches methods, including pneumatic, hydraulic, visual, acoustic quantification embolism. topic includes normalisation data vulnerability curves, requires stable values minimum maximum amount 2021), as suggested achieved Chen al. (2021). Hydraulic curves face similar challenges normalisation, main difference reference points measured reverse order, extracted embolised end, conductivity beginning dehydration experiment. Therefore, R package pneuma, will soon be made available Paulo Bittencourt, most useful. This script allow users test, an objective way, stability volumes experiments. two clear there serious connect experimental anatomical characteristics models conduits, diffusion kinetics interconduit pit membranes, conduit walls, addition other cells organs bark leaves. Modelling, instance, us estimate resources contribute extraction contribution over time (Yang Sharath Paligi Göttingen, demonstrated presentation high agreement obtained using flow-centrifuge when limited 16 s, line Unit Pipe Pneumatic model (Paligi 2021; Yang Moreover, Luciano Pereira (Ulm University, experiments longer intervals 2.5 min useful prediction dissolved sap well-irrigated Citrus sinensis. results presented him concentrations frequently higher than what would predicted based Henry's law, soluble showed diurnal patterns associated potential. Gas saturation oversaturation previously (Schenk 2016), raises puzzling question exactly able oversaturated under negative pressure without constant formation Up now, large-scale evaporation-driven devices synthetic trees unable accomplish achievement completely degassed, pure water. More should paid mesoporous membranes (i.e. pore diameter 5 50 nm) conducting cells. likelihood relatively large constrictions decrease exponentially increasing membrane thickness (Kaack can easily modified, depending requirements, serve various purposes. Instead injecting into positive Cohen 2003), cut-open vessels no end wall stem segment given length) resulted method study hydraulically weighted vessel length distributions 2020b). assumption much slower hydrated lumina. Although modelling relies random distribution ends, it interesting see if could improve our insights intra-tree variation length, nonrandom near nodes, side branches, stem–leaf transitions. Such compartmentalisation, segmentation, sectoriality (Guan We expect up possibilities pathways resistances, both outside xylem. An example micro electro-mechanical sensors (MEMS) used detect acoustically Dinko Oletić (Zagreb Croatia). working crops field, he uses low power acquisition systems situ machine learning processing evaluate emissions induced drought stress, currently seeking collaboration test validate emission instrumentation. Pneumatics field addresses mechanical properties gases, exciting about One presentations beyond pneumatics provided Roberto Salomón (Universidad Politécnica de Madrid, Spain), who role CO2 tree stems 2). Based 13CO2 labelling three species (maple, oak, cedar), interspecific differences efflux assimilation xylem-transported partly explained different radial diffusivity, anatomy (Salomón Despite advances fate CO2, extent re-fixation respired might enhanced species. fraction labelled, sink detected (‘dark carbon’), highlighting remains puzzling. Obviously, growing Various topics, yet meetings, include, instance 1): production, consumption, greenhouse methane (Putkinen 2021); conductance leaves, functional link cell (Flexas exchange via lenticels; tissues relation respiration woody (Teskey 2008). oxygenation relevant aquatic leaves periodically permanently immersed Internal pressures play biomechanics 2004), volatile organic compounds produced emitted gaseous form functions pollinator attraction, defence against herbivory, neighbouring plants) regulate aerosol production. Bringing these highly topics fields seem ambitious, certainly rewarding hopefully stimulate multidisciplinary collaboration. Future voluntary basis. Anyone interested biology welcome attend sessions, encourage early-career join. Presentations recorded during (https://short.boku.ac.at/kzrgd9). pleased note future conference Hyytiälä Forest Field Station Finland envisaged, preliminary date scheduled 2023. Readers contact authors information feedback. For like remind them lyrics Rolling Stones' Jumpin' Jack Flash: ‘but it's alright fact gas!’ thank speakers participants attended constructive fruitful discussions. SJ acknowledges financial support Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, project numbers 457287575 410768178). PRLB UK NERC standard grant (NE/V000071/1).
Language: Английский
Citations
7
Tree Physiology, Journal Year: 2024, Volume and Issue: 44(11)
Published: Oct. 10, 2024
Abstract Desert shrubs play a crucial role in controlling desertification and promoting revegetation, but drought often hinders their growth. Investigating the hydraulic strategies of desert is important order to understand adaptation predict future dynamics under climate change. In this study, we measured hydraulic-related characteristics roots, stems leaves 19 shrub species from northern China. We aimed explore coordination segmentation between different plant organs. The results were as follows: (i) specific root length was positively correlated with water potential inducing 50% loss stem conductivity (P50stem) negatively safety margin. This suggested that uptake efficiency fine roots traded off embolism resistance safety. (ii) leaf conductance significantly less negative than P50stem, turgor point indicating main terminal (iii) most indicated wilting occurred after substantial embolism. high desiccation may serve an physiological mechanism increase carbon gain relatively brief growth period. summary, study elucidated employed by whole-plant perspective.
Language: Английский
Citations
1
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2021, Volume and Issue: unknown
Published: Feb. 10, 2021
Abstract The Pneumatic method has been introduced to quantify embolism resistance in plant xylem of various organs. Despite striking similarity vulnerability curves between the and hydraulic methods, a modeling approach is highly needed demonstrate that can be accurately quantified based on gas diffusion kinetics. A Unit Pipe (UPPn) model was developed estimate from intact conduits, which were axially interconnected by interconduit pit membranes. physical laws used included Fick’s law for diffusion, Henry’s concentration partitioning liquid phases at equilibrium, ideal law. UPPn showed 91% extracted came first two series embolized, only 9% aqueous phase after 15 s simulation. Embolism measured with apparatus systematically overestimated 2 17%, corresponding typical measuring error 0.11 MPa P 50 (the water potential equivalent 50% maximum amount extracted). Because results are supported experimental evidence, there good theoretical basis applying pneumatic research angiosperms.
Language: Английский
Citations
9
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown
Published: Jan. 6, 2022
Abstract Despite a long research history, we do not fully understand why plants are able to transport xylem sap under negative pressure without constant failure. Microbubble formation via direct gas entry is assumed cause hydraulic failure, while the concentration of dissolved in traditionally supposed be constant, following Henry’s law. Here, soluble was estimated vivo using well-watered Citrus varying levels air temperature and photoperiodic exposure, compared modelled data. The showed non-equilibrium curves, with minimum over- or undersaturation 5% solubility based on A similar diurnal pattern obtained from cut-open conduits discharge tube, oversolubility strongly associated decreasing water potentials during transpiration. Although our model did explain daily changes for an anisobaric situation, characterises nanoconfined liquids, such as inside cell walls. Thus, relatively high amounts gas, providing them buffering capacity prevent despite temperature.
Language: Английский
Citations
6
Forests, Journal Year: 2023, Volume and Issue: 14(2), P. 293 - 293
Published: Feb. 2, 2023
The pneumatic method is a novel determining vulnerability to embolism in plants, yet it remains unclear whether this suitable for all species with different xylem anatomy. In study, using six tree contrasting anatomy, including four vessel-bearing (diffuse-porous wood and ring-porous wood) two tracheid-bearing (non-porous wood), we test the reliability of by comparing hydraulic methods also considering turgor loss point native embolism. Vessel length distribution cut-open vessel volume were evaluated silicone injection technique. Additionally, synthesized published data find out consistency between methods. Results showed that there was maximum 10-folds difference mean diameter varying from 30 56 μm among species. estimated open ranges 0.064 0.397 mL, 14% tube vacuum reservoir. For species, good methods, evidenced significantly overestimated because bad consistencies plant water relations. Data synthesis suggested can accurately measure but not Our study provided further evidence accurate most thus has potential be widely used hydraulics field. However, proposed precise calculation air discharge should take into account vessels wide long vessels.
Language: Английский
Citations
2
New Phytologist, Journal Year: 2022, Volume and Issue: 237(2), P. 384 - 391
Published: Dec. 20, 2022
The integrity of the plant water transport system is crucial for performance and survival (Rowland et al., 2015). To estimate vulnerability to drought-induced embolism (blockage flow in conduits by air bubbles), a number methods have been developed generate curves (VCs), that is, relationship between xylem level potential (Cochard 2013). However, since report 'cutting-under-tension' artifact (Wheeler 2013), all published VCs may need be re-examined, researchers carefully avoid artifacts 2013; Zhang & Holbrook, 2014). As newly method, Pneumatic method (the manual or automated Pneumatron) measures volume discharged from terminal shoots (Pereira 2016, 2020). This assumes increase during desiccation mainly extracted embolized conduits, it believed non-hydraulic, economical, less time-consuming method. also generates P50 (water causing 50% embolism) values comparable other some studies 2016; Bittencourt 2018; Pereira 2020; Paligi 2021; see summary Brum 2023). All current both advantages limitations (Skelton Diaz, 2020), so does We pointed out uncertainties our early study (Chen 2021) could improved solving these uncertainties. In an article this issue New Phytologist, al. (2023; pp. 374–383), provided explanations on issues we raised before, but think fundamental remain not well addressed. main criticism reply Letter (2023) earlier incorrectly performed experiment, stopped measurement too early, which resulted underestimated ADmax (maximum discharged) resistance. Here, claim presented 'stop early' late' previous paper, clearly stopping time would affect estimation VCs, termed as 'two-plateau' concern (see fig. 6 Chen 2021, define 'plateau' stage maintains stable value relatively long duration; diagram Fig. 1 here). Our using plateau overestimate vulnerability, whereas 2 underestimate due source 2. Furthermore, believe (AD) at only represents maximum dischargeable vessels, includes sources, example, tissue shrinkage, cracks pith discussion). Therefore, measured ADmax, rather separated into two stages, uncertainties, mechanistic explanations. misinterpreted 'incorrect implementation underestimation ADmax' they did address directly. Additionally, new data obtained Pneumatron (constructed following Trabi Supporting Information Methods S1) agree with generated pneumatic device (Fig. S1), supporting concerns showing there were no technological biases study. A diagrammatic representation sources stem spread embolisms use under conditions well-hydrated (a), moderate dehydration (b), severe (c), full (d) stages. green color indicates functioning vessels red distal end stem, are isolated vessels. white orange colors indicate cut-open intact neighboring basal end, respectively. Arrows direction extraction. insets show status pits connecting adjacent refers information S9 (2021) S4 (2016). right column (refers shows kinetics (ΔVi, μl) (e) one representative sample Lasiococca comberi method; percentage against different segments (f); comparison plateaus (blue) (red) (g), respectively, L. comberi. See detailed descriptions (2021). pattern was first reported 2021). Interestingly, now found multi-plateaus (> 2) when lasts enough (c. > 8 d; Figs 2, S2–S6). paper (fig. showed AD desiccation, increased reached certain (plateau 1), then again another 2). Similarly, 'two- multi-plateau' can studies, including who (2020) reproduced S7–S9). Notably, combining replicates figure 1g, S7), easily masked great variation among samples small compared completely dehydrated late stage. questioned reliability measurements used extremely low estimated potential. While predicted negative potentials might reliable directly values, change 'multi-plateau' (also S1). patterns suggest should ignored addressed carefully. hypothesized explained isolation cut part branch, visually illustration here 1). gas dynamics model Jansen Yang (2022), apparatus discharges while water-filled excluded. Thus, initial close because cavitated apparatus. section 1b), more prone their proximity discussion about open vessel later). Then, starts connects 1e), reaches second (or third) most embolize 1d). Importantly, include likely stage, calculated (PAD) undoubtedly underestimates Although lower reasonable if Uncertainties section). essential determination definite, quantitative, easy-to-follow criterion has established even now. degree leaves important indicator experiment For (2016) initially described 'when Ψx than limit pressure chamber (−10 MPa) branches had lost leaves'. study, followed 'leaves severely desiccated, crispy, started shed' 'the increasing decrease' 2021), occurred −2 −7 MPa let continue dehydrate d), occurrence third many (Figs (2018) defined last point branch where fully embolized'. maintain within 24 h' 'measurements dehydrated'. Generally, hard follow. First, rare took time, example d S2–S6), generally −10 3 These durations reaching final Second, second) short varies species probably associated anatomy needs further case covers wide range (e.g. longer study; Table S1 interpreted chambers measure accurately (range −4 commercial equipment). uncertainty easy happen follow protocol (2016), qualitatively 'ADmax, its (lowest Ψx)'. brought methodology. By recent standard (Trabi 2023), stop doing maintained stable. 1e) being exclude possibility difficulties measuring potentials, especially highly resistant those drying slowly. words, reach plateau. Third, technique quantify whole vivo, arbitrarily decide timing measurement. Obviously, unknown whether 100% criteria, suggesting insufficient thus well. very occur plants enough. tested visualization micro-CT) check before total cumulative saturation reductions potential' 'reach device'. after period 2), typically several days much At already declined below MPa, obvious shrinkage appearance. rules. An S7). Based model, paradoxical suggestion twice P50'. Because users methods, impractical suggestion. On contrary, given construct claimed woody cracks, leaky tissue, occur, connected conduits. concluded common problems tree species. disagree micro-CT images connect Meanwhile, cautious dry necessarily equal amount evidence non-vessel cause value. connections 3; Video challenging assumption 'if do area influence extraction'. Combretum griffithii, liana big area, 24-h dehydration, three 48 h S10). supported 10 20 studied (Table S2) xylems piths entire over 60 −5.51 −9.41 MPa; 3, S11; large abundant parenchyma tissues. contaminate treated argued detected 7 sections micro-CT. m) After underwater, tubing scanning. segment wrapped parafilm reduce scanning reason expect artificial preparation apparatus, place exposed quickly. Further experimental support parts contributed discharge that, stems (by quick air-injection) 28–33% It suggested fast glue block (Zhang 2018) leaking pith, treatment leakage positions still tested. declines strongly shrinkage. 'stable cases, sometimes, decrease S2–S6, S7, 6a suggests affected factors, such areas shrunk 4.5–14.0%, 2.9–12.1%, lumen varied S12). contribution vary across extent VC parameters remains unclear. solved avoided simply paying 'careful attention practices' (2023). cut-open-vessel effect like 'Unlike sampling hydraulic measurements, material filled purpose'; additional tests needed 'r-shaped' high cases −1 S2–S6 When performing measurement, contact outside clear seeding embolism. pre-existing embolism, vessels) (Brodersen Guan If true, result overestimation least four Citrus sinensis vulnerable S8) Other treatment, same numerous minimize far away (Torres-Ruiz contrast, extract adjunct (Jansen 2022). Also, calculation PAD level. diffusion speed through pit membranes orders magnitude bulk flow, relative importance farther depends anatomy, membrane thickness, connectivity, on. traits differ considerably introduce species-specific direction. quantifies 2022), theory, correct curve initiates spreads toward end. Otherwise, excluding events heterogeneity along stages (See S2), consistently S13). synthesis derived traditional reference general agreements (but diverged : line caution paid apply large-scale Sergent correlation solve mentioned earlier, misleading terms eco-physiological performance. behaved cavitation initiation (less negative) (in −0.5 e.g. figs 1, give us frequent recovery diurnal basis. confirmed 'non-s-shaped' enough, regarding how perform natural world. possible unlikely initiated MPa. validate re-verified noticed validating often mixed, collected literature comparing 2018). revealed individual (Shen recommend careful approach controversies methodology settled, intraspecific variation, single avoided. discharging overestimates lack pathway opposite effect. vulnerability. effects merged, methods. analogous content, correlated process spreading desiccation. Simply content easier, plotting produce 's-shaped' similar S4), decline (Hao 4 correlation, ongoing structural physiological processes related process. getting helpful, shape underlying mechanisms matter. conclusion, potentially efficient time-saving remain. Before widely massive dataset, discussed pattern, verified. Surely, novel advance scientific knowledge, perfect solid data. We, therefore, test correlations, generating up Some done track ends discharge. insights pointing evidence-based promote improvement advancement understanding central topic physiology ecology. Rather invalidating wish help improve authors thank Peng-Yun Yan, Lu Han, Lian-Bin Tao, Weng-Zhuang assistance Si-Qi Li, Yu-Hang He, En-Guo Rong, Zhuang-Sheng Xiao, Lin designing constructing devices. work funded National Natural Science Foundation China (32071735, 41861144016, 31570406, 31861133008), 'Light West China' Program Southeast Asia Biodiversity Research Institute, Chinese Academy Sciences (151C53KYSB20200019), Yunnan Provincial Technology Department (2018HB068), Revitalization Talents Support Plan (YNWR-QNBJ-2019177). PM acknowledges financial CAS-TWAS President's Fellowship International Doctoral Students. Y-JZ Open Fund CAS Key Laboratory Tropical Forest Ecology. Y-JC, conceived designed Y-JC experiments. analyzed wrote revised manuscript input J-LZ. equally work. Comparison device. S2 dynamic changes (PAD, %) Microcos paniculate S3 Lagerstroemia tomentosa S5 griffithii S6 yunnanense S7 Reproduction 5 (2020), 'two Plateaus', non-stable S8 Plateaus' sinensis. (2021), Plateaus'. S10 (side cross-section directions) S11 tropical c. laboratory potentials. S12 S13 determine branch. five determining Tissue monitoring. Vulnerability measurements. air-discharging Species observation crack dehydration. Movie three-dimensional Please note: Wiley responsible functionality any supplied authors. Any queries (other missing material) directed Phytologist Central Office. publisher content) corresponding author article.
Language: Английский
Citations
3
Plant Biology, Journal Year: 2024, Volume and Issue: 26(4), P. 633 - 646
Published: April 8, 2024
Abstract The African Restionaceae (Poales), the dominant graminoid layer in megadiverse Cape Floristic Region of South Africa, are distributed across a wide range moisture availability, yet currently there is very little known about underlying hydraulics this group. We tested two methods for measuring culm vulnerability to embolism, optical and pneumatic methods, three species Cannomois ranging habitat from semi‐riparian ( virgata ) dryland parviflora C. congesta ). Estimates xylem were coupled with measures turgor loss point (Ψ TLP minimum field water potential MD assess hydraulic safety margins. produced similar estimates P 50 , but differed 12 88 . All quite vulnerable –1.9 MPa ), −2.3 −2.4 Ψ aligned stress, highest values found Consistent differences between resulted consistent margins 0.96 ± 0.1 onset embolism occurring 0.43 0.04 after all species. Our study demonstrates that restio occupancy dry environments involves more than evolution highly resistant xylem, suggesting other aspects relations key understanding trait–environment relationships
Language: Английский
Citations
0
Tree Physiology, Journal Year: 2024, Volume and Issue: unknown
Published: July 24, 2024
Abstract Considerable attention has been paid to addressing methodological concerns related measurements of embolism in conduits angiosperm xylem. A fast, easy and cheap method is based on gas extraction from dehydrating samples obtain pneumatic vulnerability curves (VCs). Here, we tested the assumption that cutting open leads gas-filled lumina when these are cut air at fairly high water potentials, which required detect intact conduits. We performed VCs with Pneumatron for 12 species extracted sap cut-open vessels branches nine under early stages branch dehydration. The optical was applied Citrus plants as an alternative reference estimate resistance. found increase discharge during dehydration, affected most studied. Xylem residue not absorbed immediately by surrounding tissue six but gradually disappeared over time progressive amount discharged increased until all residual absorbed, embolism. conclude xylem affects represents a novel artifact can easily be corrected for. Yet, it remains unclear why exactly air–water meniscus did fully withdraw conduit end wall species. By analyzing slope time, could improve estimations resistance, evidenced strong agreement between methods. Since some slightly underestimate propose apply correction this time-resolution taken Pneumatron.
Language: Английский
Citations
0