Remaining uncertainties in the Pneumatic method DOI Open Access
Yajun Chen, Phisamai Maenpuen, Jiao‐Lin Zhang

и другие.

New Phytologist, Год журнала: 2022, Номер 237(2), С. 384 - 391

Опубликована: Дек. 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.

Язык: Английский

Functional xylem characteristics associated with drought‐induced embolism in angiosperms DOI Open Access
Frederic Lens, Sean M. Gleason, Giovanni Bortolami

и другие.

New Phytologist, Год журнала: 2022, Номер 236(6), С. 2019 - 2036

Опубликована: Авг. 30, 2022

Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant reduced productivity and mortality. Methods to assess this vulnerability are difficult achieve at scale, leading alternative metrics correlations with more easily measured traits. These efforts have led longstanding pervasive assumed mechanistic link between vessel diameter angiosperms. However, there least two problems assumption that requires critical re-evaluation: (1) our current understanding does not provide explanation why increased width should lead greater vulnerability, (2) most recent advancements nanoscale processes suggest direct driver. Here, we review data physiological comparative wood anatomy studies, highlighting potential anatomical physicochemical drivers formation spread. We then put forward knowledge gaps, emphasising what known, unknown speculation. A meaningful evaluation diameter-vulnerability will require better biophysical level determine spread, which turn accurate predictions how water transport affected by drought.

Язык: Английский

Процитировано

113
A unit pipe pneumatic model to simulate gas kinetics during measurements of embolism in excised angiosperm xylem DOI
Dongmei Yang, Luciano Pereira, Guoquan Peng

и другие.

Tree Physiology, Год журнала: 2022, Номер 43(1), С. 88 - 101

Опубликована: Сен. 1, 2022

Abstract The pneumatic method has been introduced to quantify embolism resistance in plant xylem of various organs by applying a partial vacuum cut-open xylem. Despite the similarity vulnerability curves between and other methods, modeling approach is needed investigate if changes during dehydration can be accurately quantified based on gas diffusion kinetics. Therefore, unit pipe (UPPn) model was developed estimate extraction from intact conduits, which were axially interconnected inter-conduit pit membranes conduits. physical laws used included Fick’s law for diffusion, Henry’s concentration partitioning liquid phases at equilibrium ideal law. UPPn showed that 91% extracted came first five series embolized, conduits only 9% aqueous phase after 15 s simulation. Considering alternative sources, measured with pneumatron device systematically overestimated 2–17%, corresponded typical measuring error 0.11 MPa P50 (the water potential equivalent 50% maximum amount extracted). It concluded directly measure due fast movement across interconduit membranes, while sap hydrated cell walls about 100 times slower. We expect will also contribute understanding propagation temporal dynamics.

Язык: Английский

Процитировано

18
Gas diffusion kinetics in relation to embolism formation and propagation in angiosperm xylem: a mini-review DOI
Lincon Matheus Araujo Silva,

B. Bujnowski,

Luciano Pereira

и другие.

Acta Horticulturae, Год журнала: 2025, Номер 1419, С. 123 - 134

Опубликована: Фев. 1, 2025

Язык: Английский

Процитировано

0
Reconciling discrepancies in measurements of vulnerability to xylem embolism with the pneumatic method DOI Open Access
Mauro Brum, Luciano Pereira, Rafael Vasconcelos Ribeiro

и другие.

New Phytologist, Год журнала: 2022, Номер 237(2), С. 374 - 383

Опубликована: Дек. 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.

Язык: Английский

Процитировано

10
Plasticity in branch water relations and stem hydraulic vulnerability enhances hydraulic safety in mangroves growing along a salinity gradient DOI Creative Commons
Holly A. A. Beckett, Callum Bryant, Teresa Neeman

и другие.

Plant Cell & Environment, Год журнала: 2023, Номер 47(3), С. 854 - 870

Опубликована: Ноя. 17, 2023

Abstract Coping with water stress depends on maintaining cellular function and hydraulic conductance. Yet measurements of vulnerability to drought salinity do not often focus capacitance in branch organs that buffer during stress. The relationships between relations, stem anatomy were investigated two co‐occurring mangroves Aegiceras corniculatum Rhizophora stylosa growing at low high salinity. dynamics release acted conserve content the expense foliage extended drying. Hydraulic redistribution from increased relative by up 21%. potentials which 12% 50% loss conductivity occurred decreased ~1.7 MPa both species sites. These coordinated tissue adjustments safety despite declining turgor margins higher Our results highlight complex interplay plasticity organ‐level relations maintenance distributed along gradients. emphasise importance combining parameters understand across whole plant.

Язык: Английский

Процитировано

5
Vessel, intervessel pits and vessel-to-fiber pits have significant impact on hydraulic function under different drought conditions and re-irrigation DOI
Qing Liu, Ying Liu,

Liqiang Gao

и другие.

Environmental and Experimental Botany, Год журнала: 2023, Номер 214, С. 105476 - 105476

Опубликована: Авг. 19, 2023

Язык: Английский

Процитировано

4
Remaining uncertainties in the Pneumatic method DOI Open Access
Yajun Chen, Phisamai Maenpuen, Jiao‐Lin Zhang

и другие.

New Phytologist, Год журнала: 2022, Номер 237(2), С. 384 - 391

Опубликована: Дек. 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.

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