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Arce Cubas L, Rodrigues Gabriel Sales C, Vath RL, Bernardo EL, Burnett AC, Kromdijk J. Lessons from relatives: C4 photosynthesis enhances CO2 assimilation during the low-light phase of fluctuations. Plant Physiol 2023; 193:1073-1090. [PMID: 37335935 PMCID: PMC10517189 DOI: 10.1093/plphys/kiad355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/19/2023] [Accepted: 06/03/2023] [Indexed: 06/21/2023]
Abstract
Despite the global importance of species with C4 photosynthesis, there is a lack of consensus regarding C4 performance under fluctuating light. Contrasting hypotheses and experimental evidence suggest that C4 photosynthesis is either less or more efficient in fixing carbon under fluctuating light than the ancestral C3 form. Two main issues have been identified that may underly the lack of consensus: neglect of evolutionary distance between selected C3 and C4 species and use of contrasting fluctuating light treatments. To circumvent these issues, we measured photosynthetic responses to fluctuating light across 3 independent phylogenetically controlled comparisons between C3 and C4 species from Alloteropsis, Flaveria, and Cleome genera under 21% and 2% O2. Leaves were subjected to repetitive stepwise changes in light intensity (800 and 100 µmol m-2 s-1 photon flux density) with 3 contrasting durations: 6, 30, and 300 s. These experiments reconciled the opposing results found across previous studies and showed that (i) stimulation of CO2 assimilation in C4 species during the low-light phase was both stronger and more sustained than in C3 species; (ii) CO2 assimilation patterns during the high-light phase could be attributable to species or C4 subtype differences rather than photosynthetic pathway; and (iii) the duration of each light step in the fluctuation regime can strongly influence experimental outcomes.
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Affiliation(s)
- Lucίa Arce Cubas
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA Cambridge, UK
| | | | - Richard L Vath
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA Cambridge, UK
| | - Emmanuel L Bernardo
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA Cambridge, UK
- Institute of Crop Science, College of Agriculture and Food Science, University of the Philippines Los Baños, College, Laguna 4031, Philippines
| | - Angela C Burnett
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA Cambridge, UK
| | - Johannes Kromdijk
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA Cambridge, UK
- Carl R Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Cubas LA, Vath RL, Bernardo EL, Sales CRG, Burnett AC, Kromdijk J. Corrigendum: Activation of CO 2 assimilation during photosynthetic induction is slower in C 4 than in C 3 photosynthesis in three phylogenetically controlled experiments. Front Plant Sci 2023; 14:1188404. [PMID: 37063226 PMCID: PMC10090652 DOI: 10.3389/fpls.2023.1188404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
[This corrects the article DOI: 10.3389/fpls.2022.1091115.].
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Affiliation(s)
- Lucía Arce Cubas
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Richard L. Vath
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Emmanuel L. Bernardo
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
- University of the Philippines Los Baños, Institute of Crop Science, College of Agriculture and Food Science, College, Laguna, Philippines
| | | | - Angela C. Burnett
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Johannes Kromdijk
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
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Arce Cubas L, Vath RL, Bernardo EL, Sales CRG, Burnett AC, Kromdijk J. Activation of CO 2 assimilation during photosynthetic induction is slower in C 4 than in C 3 photosynthesis in three phylogenetically controlled experiments. Front Plant Sci 2023; 13:1091115. [PMID: 36684779 PMCID: PMC9848656 DOI: 10.3389/fpls.2022.1091115] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/05/2022] [Indexed: 05/31/2023]
Abstract
INTRODUCTION Despite their importance for the global carbon cycle and crop production, species with C4 photosynthesis are still somewhat understudied relative to C3 species. Although the benefits of the C4 carbon concentrating mechanism are readily observable under optimal steady state conditions, it is less clear how the presence of C4 affects activation of CO2 assimilation during photosynthetic induction. METHODS In this study we aimed to characterise differences between C4 and C3 photosynthetic induction responses by analysing steady state photosynthesis and photosynthetic induction in three phylogenetically linked pairs of C3 and C4 species from Alloteropsis, Flaveria, and Cleome genera. Experiments were conducted both at 21% and 2% O2 to evaluate the role of photorespiration during photosynthetic induction. RESULTS Our results confirm C4 species have slower activation of CO2 assimilation during photosynthetic induction than C3 species, but the apparent mechanism behind these differences varied between genera. Incomplete suppression of photorespiration was found to impact photosynthetic induction significantly in C4 Flaveria bidentis, whereas in the Cleome and Alloteropsis C4 species, delayed activation of the C3 cycle appeared to limit induction and a potentially supporting role for photorespiration was also identified. DISCUSSION The sheer variation in photosynthetic induction responses observed in our limited sample of species highlights the importance of controlling for evolutionary distance when comparing C3 and C4 photosynthetic pathways.
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Affiliation(s)
- Lucía Arce Cubas
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Richard L. Vath
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Emmanuel L. Bernardo
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
- University of the Philippines Los Baños, Institute of Crop Science, College of Agriculture and Food Science, College, Laguna, Philippines
| | | | - Angela C. Burnett
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
| | - Johannes Kromdijk
- The University of Cambridge, Department of Plant Sciences, Cambridge, United Kingdom
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Burnett AC, Kromdijk J. Can we improve the chilling tolerance of maize photosynthesis through breeding? J Exp Bot 2022; 73:3138-3156. [PMID: 35143635 PMCID: PMC9126739 DOI: 10.1093/jxb/erac045] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 02/02/2022] [Indexed: 05/11/2023]
Abstract
Chilling tolerance is necessary for crops to thrive in temperate regions where cold snaps and lower baseline temperatures place limits on life processes; this is particularly true for crops of tropical origin such as maize. Photosynthesis is often adversely affected by chilling stress, yet the maintenance of photosynthesis is essential for healthy growth and development, and most crucially for yield. In this review, we describe the physiological basis for enhancing chilling tolerance of photosynthesis in maize by examining nine key responses to chilling stress. We synthesize current knowledge of genetic variation for photosynthetic chilling tolerance in maize with respect to each of these traits and summarize the extent to which genetic mapping and candidate genes have been used to understand the genomic regions underpinning chilling tolerance. Finally, we provide perspectives on the future of breeding for photosynthetic chilling tolerance in maize. We advocate for holistic and high-throughput approaches to screen for chilling tolerance of photosynthesis in research and breeding programmes in order to develop resilient crops for the future.
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Affiliation(s)
- Angela C Burnett
- Department of Plant Sciences, University of CambridgeCambridge, UK
- Correspondence:
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Burnett AC, Serbin SP, Davidson KJ, Ely KS, Rogers A. Detection of the metabolic response to drought stress using hyperspectral reflectance. J Exp Bot 2021; 72:6474-6489. [PMID: 34235536 DOI: 10.1093/jxb/erab255] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
Drought is the most important limitation on crop yield. Understanding and detecting drought stress in crops is vital for improving water use efficiency through effective breeding and management. Leaf reflectance spectroscopy offers a rapid, non-destructive alternative to traditional techniques for measuring plant traits involved in a drought response. We measured drought stress in six glasshouse-grown agronomic species using physiological, biochemical, and spectral data. In contrast to physiological traits, leaf metabolite concentrations revealed drought stress before it was visible to the naked eye. We used full-spectrum leaf reflectance data to predict metabolite concentrations using partial least-squares regression, with validation R2 values of 0.49-0.87. We show for the first time that spectroscopy may be used for the quantitative estimation of proline and abscisic acid, demonstrating the first use of hyperspectral data to detect a phytohormone. We used linear discriminant analysis and partial least squares discriminant analysis to differentiate between watered plants and those subjected to drought based on measured traits (accuracy: 71%) and raw spectral data (66%). Finally, we validated our glasshouse-developed models in an independent field trial. We demonstrate that spectroscopy can detect drought stress via underlying biochemical changes, before visual differences occur, representing a powerful advance for measuring limitations on yield.
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Affiliation(s)
- Angela C Burnett
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Shawn P Serbin
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kenneth J Davidson
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kim S Ely
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Alistair Rogers
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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Burnett AC, Anderson J, Davidson KJ, Ely KS, Lamour J, Li Q, Morrison BD, Yang D, Rogers A, Serbin SP. A best-practice guide to predicting plant traits from leaf-level hyperspectral data using partial least squares regression. J Exp Bot 2021; 72:6175-6189. [PMID: 34131723 DOI: 10.1093/jxb/erab295] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 06/12/2023]
Abstract
Partial least squares regression (PLSR) modelling is a statistical technique for correlating datasets, and involves the fitting of a linear regression between two matrices. One application of PLSR enables leaf traits to be estimated from hyperspectral optical reflectance data, facilitating rapid, high-throughput, non-destructive plant phenotyping. This technique is of interest and importance in a wide range of contexts including crop breeding and ecosystem monitoring. The lack of a consensus in the literature on how to perform PLSR means that interpreting model results can be challenging, applying existing models to novel datasets can be impossible, and unknown or undisclosed assumptions can lead to incorrect or spurious predictions. We address this lack of consensus by proposing best practices for using PLSR to predict plant traits from leaf-level hyperspectral data, including a discussion of when PLSR is applicable, and recommendations for data collection. We provide a tutorial to demonstrate how to develop a PLSR model, in the form of an R script accompanying this manuscript. This practical guide will assist all those interpreting and using PLSR models to predict leaf traits from spectral data, and advocates for a unified approach to using PLSR for predicting traits from spectra in the plant sciences.
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Affiliation(s)
- Angela C Burnett
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Jeremiah Anderson
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kenneth J Davidson
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kim S Ely
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Julien Lamour
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Qianyu Li
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Bailey D Morrison
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Dedi Yang
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Alistair Rogers
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Shawn P Serbin
- Terrestrial Ecosystem Science and Technology Group, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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Burnett AC, Serbin SP, Lamour J, Anderson J, Davidson KJ, Yang D, Rogers A. Seasonal trends in photosynthesis and leaf traits in scarlet oak. Tree Physiol 2021; 41:1413-1424. [PMID: 33611562 DOI: 10.1093/treephys/tpab015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Understanding seasonal variation in photosynthesis is important for understanding and modeling plant productivity. Here, we used shotgun sampling to examine physiological, structural and spectral leaf traits of upper canopy, sun-exposed leaves in Quercus coccinea Münchh (scarlet oak) across the growing season in order to understand seasonal trends, explore the mechanisms underpinning physiological change and investigate the impact of extrapolating measurements from a single date to the whole season. We tested the hypothesis that photosynthetic rates and capacities would peak at the summer solstice, i.e., at the time of peak photoperiod. Contrary to expectations, our results reveal a late-season peak in both photosynthetic capacity and rate before the expected sharp decrease at the start of senescence. This late-season maximum occurred after the higher summer temperatures and vapor pressure deficit and was correlated with the recovery of leaf water content and increased stomatal conductance. We modeled photosynthesis at the top of the canopy and found that the simulated results closely tracked the maximum carboxylation capacity of Rubisco. For both photosynthetic capacity and modeled top-of-canopy photosynthesis, the maximum value was therefore not observed at the summer solstice. Rather, in each case, the measurements at and around the solstice were close to the overall seasonal mean, with values later in the season leading to deviations from the mean by up to 41 and 52%, respectively. Overall, we found that the expected Gaussian pattern of photosynthesis was not observed. We conclude that an understanding of species- and environment-specific changes in photosynthesis across the season is essential for correct estimation of seasonal photosynthetic capacity.
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Affiliation(s)
- Angela C Burnett
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Shawn P Serbin
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Julien Lamour
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jeremiah Anderson
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Kenneth J Davidson
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Dedi Yang
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Alistair Rogers
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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8
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Burnett AC, Serbin SP, Rogers A. Source:sink imbalance detected with leaf- and canopy-level spectroscopy in a field-grown crop. Plant Cell Environ 2021; 44:2466-2479. [PMID: 33764536 DOI: 10.1111/pce.14056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 05/21/2023]
Abstract
The finely tuned balance between sources and sinks determines plant resource partitioning and regulates growth and development. Understanding and measuring metabolic indicators of source or sink limitation forms a vital part of global efforts to increase crop yield for future food security. We measured metabolic profiles of Cucurbita pepo (zucchini) grown in the field under carbon sink limitation and control conditions. We demonstrate that these profiles can be measured non-destructively using hyperspectral reflectance at both leaf and canopy scales. Total non-structural carbohydrates (TNC) increased 82% in sink-limited plants; leaf mass per unit area (LMA) increased 38% and free amino acids increased 22%. Partial least-squares regression (PLSR) models link these measured functional traits with reflectance data, enabling high-throughput estimation of traits comprising the sink limitation response. Leaf- and canopy-scale models for TNC had R2 values of 0.93 and 0.64 and %RMSE of 13 and 38%, respectively. For LMA, R2 values were 0.91 and 0.60 and %RMSE 7 and 14%; for free amino acids, R2 was 0.53 and 0.21 with %RMSE 20 and 26%. Remote sensing can enable accurate, rapid detection of sink limitation in the field at the leaf and canopy scale, greatly expanding our ability to understand and measure metabolic responses to stress.
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Affiliation(s)
- Angela C Burnett
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York, USA
| | - Shawn P Serbin
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York, USA
| | - Alistair Rogers
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York, USA
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Burnett AC, Davidson KJ, Serbin SP, Rogers A. The "one-point method" for estimating maximum carboxylation capacity of photosynthesis: A cautionary tale. Plant Cell Environ 2019; 42:2472-2481. [PMID: 31049970 DOI: 10.1111/pce.13574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/22/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
The maximum carboxylation capacity of Rubisco, Vc,max , is an important photosynthetic parameter that is key to accurate estimation of carbon assimilation. The gold-standard technique for determining Vc,max is to derive Vc,max from the initial slope of an A-Ci curve (the response of photosynthesis, A, to intercellular CO2 concentration, Ci ). Accurate estimates of Vc,max derived from an alternative and rapid "one-point" measurement of photosynthesis could greatly accelerate data collection and model parameterization. We evaluated the practical application of the one-point method in six species measured under standard conditions (saturating irradiance and 400 μmol CO2 mol-1 ) and under conditions that would increase the likelihood for successful estimation of Vc,max : (a) ensuring Rubisco-limited A by measuring at 300 μmol CO2 mol-1 and (b) allowing time for acclimation to saturating irradiance prior to measurement. The one-point method significantly underestimated Vc,max in four of the six species, providing estimates 21%-32% below fitted values. We identified ribulose-1,5-bisphosphate-limited A, light acclimation, and the use of an assumed respiration rate as factors that limited the effective use of the one-point method to accurately estimate Vc,max . We conclude that the one-point method requires a species-specific understanding of its application, is often unsuccessful, and must be used with caution.
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Affiliation(s)
- Angela C Burnett
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York
| | - Kenneth J Davidson
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York
| | - Shawn P Serbin
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York
| | - Alistair Rogers
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York
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Ely KS, Burnett AC, Lieberman-Cribbin W, Serbin SP, Rogers A. Spectroscopy can predict key leaf traits associated with source-sink balance and carbon-nitrogen status. J Exp Bot 2019; 70:1789-1799. [PMID: 30799496 DOI: 10.1093/jxb/erz061] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Approaches that enable high-throughput, non-destructive measurement of plant traits are essential for programs seeking to improve crop yields through physiological breeding. However, many key traits still require measurement using slow, labor-intensive, and destructive approaches. We investigated the potential to retrieve key traits associated with leaf source-sink balance and carbon-nitrogen status from leaf optical properties. Structural and biochemical traits and leaf reflectance (500-2400 nm) of eight crop species were measured and used to develop predictive 'spectra-trait' models using partial least squares regression. Independent validation data demonstrated that the models achieved very high predictive power for C, N, C:N ratio, leaf mass per area, water content, and protein content (R2>0.85), good predictive capability for starch, sucrose, glucose, and free amino acids (R2=0.58-0.80), and some predictive capability for nitrate (R2=0.51) and fructose (R2=0.44). Our spectra-trait models were developed to cover the trait space associated with food or biofuel crop plants and can therefore be applied in a broad range of phenotyping studies.
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Affiliation(s)
- Kim S Ely
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Angela C Burnett
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Wil Lieberman-Cribbin
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Shawn P Serbin
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Alistair Rogers
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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Burnett AC, Rogers A, Rees M, Osborne CP. Nutrient sink limitation constrains growth in two barley species with contrasting growth strategies. Plant Direct 2018; 2:e00094. [PMID: 31245695 PMCID: PMC6508780 DOI: 10.1002/pld3.94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 05/06/2023]
Abstract
Mineral nutrients exert important limitations on plant growth. Growth is limited by the nutrient source when it is constrained by nutrient availability and uptake, which may simultaneously limit investment in photosynthetic proteins, leading to carbon source limitation. However, growth may also be limited by nutrient utilization in sink tissue. The relative importance of these processes is contested, with crop and vegetation models typically assuming source limitations of carbon and mineral nutrients (especially nitrogen). This study compared the importance of source and sink limitation on growth in a slower-growing wild perennial barley (Hordeum bulbosum) and a faster-growing domesticated annual barley (Hordeum vulgare), by applying a mineral nutrient treatment and measuring nitrogen uptake, growth, allocation, and carbon partitioning. We found that nitrogen uptake, growth, tillering, shoot allocation, and nitrogen storage were restricted by low nutrient treatments. Multiple lines of evidence suggest that low nutrient levels do not limit growth via carbon acquisition: (a) Carbohydrate storage does not increase at high nutrient levels. (b) Ratio of free amino acids to sucrose increases at high nutrient levels. (c) Shoot allocation increases at high nutrient levels. These data indicate that barley productivity is limited by the capacity for nutrient use in growth. Models must explicitly account for sink processes in order to properly simulate this mineral nutrient limitation of growth.
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Affiliation(s)
- Angela C. Burnett
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
- Present address:
Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNew York11973
| | - Alistair Rogers
- Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNew York
| | - Mark Rees
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Colin P. Osborne
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
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Burnett AC, Rogers A, Rees M, Osborne CP. Carbon source-sink limitations differ between two species with contrasting growth strategies. Plant, Cell & Environment 2016; 39:2460-2472. [PMID: 0 DOI: 10.1111/pce.12801] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/02/2016] [Accepted: 07/11/2016] [Indexed: 05/08/2023]
Affiliation(s)
- Angela C. Burnett
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield S10 2TN UK
| | - Alistair Rogers
- Environmental and Climate Sciences Department; Brookhaven National Laboratory; Upton NY 11973 USA
| | - Mark Rees
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield S10 2TN UK
| | - Colin P. Osborne
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield S10 2TN UK
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Burnett AC, Anderson PJ, Cheong J, Doyle LW, Davey CG, Wood SJ. Prevalence of psychiatric diagnoses in preterm and full-term children, adolescents and young adults: a meta-analysis. Psychol Med 2011; 41:2463-2474. [PMID: 21733218 DOI: 10.1017/s003329171100081x] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Preterm (PT) birth and low birth weight (LBW) are high-prevalence events that are associated with adverse outcomes in the longer term, with vulnerability increasing as maturity at birth decreases. Psychiatric symptomatology appears heightened in PT/LBW survivors, though there are some discordant findings from studies using questionnaire measures, particularly with respect to anxiety and depressive symptoms. METHOD This article synthesises findings from research using clinical psychiatric diagnostic criteria in PT/LBW individuals aged 10-25 years compared with term-born peers. Key outcomes of interest were the rates of individuals receiving any psychiatric diagnosis and the number of diagnoses of anxiety or depressive disorders. RESULTS A literature search for studies reporting prevalence of 'any diagnosis' yielded five studies that met inclusion criteria, with a total of 565 PT/LBW and 533 control individuals. Also, five studies were found that reported rates of anxiety/depression (692 PT/LBW and 605 control individuals). The risk of these outcomes was increased for PT/LBW individuals compared with controls [any diagnosis: odds ratio (OR) 3.66, 95% confidence interval (CI) 2.57-5.21; anxiety or depressive disorder: OR 2.86, 95% CI 1.73-4.73]. CONCLUSIONS The studies reviewed here indicate that, in addition to monitoring and management of medical and cognitive sequelae, the psychological well-being of PT/LBW individuals should be a key part of ongoing care.
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Affiliation(s)
- A C Burnett
- Department of Psychology, The University of Melbourne, VIC, Australia.
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Burnett AC, Winyard G. Clinical audit at the heart of clinical effectiveness. J Qual Clin Pract 1998; 18:3-19. [PMID: 9563557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Clinical audit is becoming an increasingly sophisticated process now practised by a majority of clinicians. A crucial tool enabling clinicians to improve their care, it involves structured review against agreed standards. Clinical audit is a key component of each of the elements of clinical effectiveness enabling health-care interventions to achieve what is intended in the most beneficial way. A national lead in the development and integration of clinical audit into everyday practice is provided in England, with Department of Health support, by the professional bodies responsible for setting and maintaining clinical standards. The Department of Health recently published a White Paper setting out Government intentions for a greater focus on quality in health. Included in these plans is a National Institute for Clinical Excellence to support and coordinate national clinical guideline and clinical audit development programmes, as well as a greater focus on the quality, effectiveness and outcomes of care.
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Affiliation(s)
- A C Burnett
- Department of Health, NHS Executive Headquarters, Leeds, UK
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Abstract
OBJECTIVES This study aimed to assess the feasibility, sensitivity, and specificity of a systematic search of the NHS central register for twins of the same sex. DESIGN, SETTING, AND SUBJECTS Computerised searches by alphanumeric NHS number, sex, and date of birth of 1.6 million patients registered with general practitioners in Kent, followed by validation by postal questionnaire sent to 66 pairs of children, 129 pairs of adult twins, and one set of triplets. MAIN OUTCOME MEASURES These were as follows: confirmed twin status, previous involvement in research, and willingness to participate in future research based on a twin register. RESULTS The procedure was most efficient at identifying twins among children, in males born from 1930 onwards, and females born before 1940. Altogether 2397 male sets and 1684 female sets were identified as probable twins, triplets, or quadruplets with identical surnames, same dates of birth, and consecutive NHS numbers. Among a further 4004 pairs of adult females with the same dates of birth (1940-79), consecutive NHS numbers, but different (married) surnames, an estimated third are twins. Response to the postal questionnaire was 60% (197/327), including only one singleton. Only 10% of responders had previously participated in medical research, but 63% (65/103) of complete sets who responded expressed a willingness to participate in a twin register. CONCLUSIONS A systematic search of the NHS central register could identify large numbers of British twins. The procedure is efficient, reasonably sensitive, and highly specific, if supplemented by additional information from birth records for adult females born after 1939. The potential exists to create an important new resource for twin studies in Britain.
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Affiliation(s)
- D P Strachan
- Department of Public Health Sciences, St George's Hospital Medical School, London
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Burnett AC, Linden GJ. The reproducibility of the assessment of restorations by dental students and their teachers. J Dent Educ 1988; 52:568-70. [PMID: 3170919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- A C Burnett
- Department of Restorative Dentistry, School of Dentistry, Queen's University, Belfast, Northern Ireland
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