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Olmos-Ruiz R, Garcia-Gomez P, Carvajal M, Yepes-Molina L. Exploring membrane vesicles in citrus fruits: a comparative analysis of conventional and organic farming approaches. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:235-248. [PMID: 37596244 DOI: 10.1002/jsfa.12903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/03/2023] [Accepted: 08/19/2023] [Indexed: 08/20/2023]
Abstract
BACKGROUND Recently, vesicles derived from plant cell membranes have received attention for their potential use as active biomolecules and nanocarriers, and obtaining them from organic crops may be an interesting option because different farming systems can affect production, plant secondary metabolism and biochemistry of cell membranes. The present study aimed to determine how organic and conventional farming affects the mineral nutrition, gas exchange, CO2 fixation and biochemical composition of lemon fruits, which could have an impact on the different fractions of cell membranes in pulp and juice. RESULTS Organic trees had higher intrinsic water use efficiency (WUEi) but conventional trees had higher stomatal conductance (gs) and nitrogen use efficiency (NUtE). Also, organic lemons had significantly higher levels of some micronutrients (Ca, Cu, Fe and Zn). Second, the main differences in the membrane vesicles showed that organic pulp vesicles had a higher antioxidant activity and more oleic acid, whereas both types of vesicles from conventional lemons had more linoleic acid. CONCLUSION In conclusion, organic farming did not alter carbon fixation parameters but impacted nitrogen fixation and water uptake, and resulted in higher micronutrient levels in lemons. These mineral nutritional changes could be related to the higher production of membranes that showed suitable morphological traits and a high antioxidant activity, positively correlated with a high amount of oleic acid, which could have stronger cell protection characteristics. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Rafael Olmos-Ruiz
- Aquaporins Group, Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Murcia, Spain
| | - Pablo Garcia-Gomez
- Aquaporins Group, Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Murcia, Spain
| | - Micaela Carvajal
- Aquaporins Group, Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Murcia, Spain
| | - Lucia Yepes-Molina
- Aquaporins Group, Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Murcia, Spain
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Guo X, Schrader J, Shi P, Jiao Y, Miao Q, Xue J, Niklas KJ. Leaf-age and petiole biomass play significant roles in leaf scaling theory. FRONTIERS IN PLANT SCIENCE 2023; 14:1322245. [PMID: 38179478 PMCID: PMC10764501 DOI: 10.3389/fpls.2023.1322245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024]
Abstract
Foliage leaves are essential for plant survival and growth, and how plants allocate biomass to their leaves reveals their economic and ecological strategies. Prior studies have shown that leaf-age significantly influences leaf biomass allocation patterns. However, unravelling the effects of ontogeny on partitioning biomass remains a challenge because it is confounded by the effects of environmental factors. Here, we aim to elucidate whether leaf-age affects the allocation to the lamina and petiole by examining leaves of known age growing in the same general environmental context. We sampled 2698 Photinia serratifolia leaves developing in the same environment from April to November 2021, representing eight leaf-ages (n > 300 for each leaf-age). Petiole and lamina biomass, and lamina area were measured to evaluate the scaling relationships using reduced major axis regression protocols. The bootstrap percentile method was used to determine the differences in scaling exponents among the different leaf-ages. ANOVA with Tukey's HSD was used to compare the ratios of petiole and lamina biomass to lamina area across the leaf-ages. Correlation tests were used to determine if exponents, intercepts, and ratios differed significantly across the different leaf-ages. The data indicated that (i) the ratio of petiole and lamina biomass to lamina area and the scaling exponent of lamina biomass versus lamina area correlate positively with leaf-age, and (ii) the scaling exponent of petiole biomass versus lamina area correlates negatively with leaf-age. Leaf maturation process involves an inverse proportional allocation between lamina and petiole biomass for expanding photosynthetic area. This phenomenon underscores the effect of leaf-age on biomass allocation and the importance of adopting an ontogenetic perspective when entertaining plant scaling theories and unravelling the principles governing shifts in biomass allocation throughout the leaf lifespan.
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Affiliation(s)
- Xuchen Guo
- Co-Innovation Centre for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Julian Schrader
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peijian Shi
- Co-Innovation Centre for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Yabing Jiao
- Co-Innovation Centre for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Qinyue Miao
- Co-Innovation Centre for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Jianhui Xue
- Co-Innovation Centre for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
- Institute of Botany, Jiangsu Province and Chinese Academy Sciences, Nanjing, China
| | - Karl J. Niklas
- School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
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Tanaka T, Kurokawa C, Oikawa S. Leaf shedding increases the photosynthetic rate of the canopy in N2-fixing and non-N2-fixing woody species. TREE PHYSIOLOGY 2018; 38:1903-1911. [PMID: 30219918 DOI: 10.1093/treephys/tpy104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/22/2018] [Indexed: 06/08/2023]
Abstract
It has long been hypothesized that timing of leaf shedding is critical for plant fitness but there is little experimental evidence to support the hypothesis. According to an optimality theory, shedding of old leaves increases canopy photosynthesis despite some nitrogen (N) being lost as litterfall, when the ratio of daily photosynthesis to leaf N (N-use efficiency, ε) in old leaves, expressed as a fraction of ε in new leaves, becomes lower than the fraction of leaf N that is resorbed before shedding (RN). This was shown to be true for N-poor plants but not for N-rich plants in a pot experiment; however, the use of planting pots imposes a variety of physical, chemical and biological constraints that could change the experimental results. Here we conducted a 3-year field survey in a cool temperate deciduous forest to examine whether Alnus sieboldiana Matsum. (N2-fixing) and Carpinus tschonoskii Maxim. (non-N2-fixing) shed their leaves to increase canopy photosynthesis in accord with the above criterion. These species often grow sympatrically and were chosen as representatives of N-rich and N-poor plants, respectively. Overall, daily photosynthesis decreased with leaf age, accompanied by small changes in leaf N, resulting in a decrease in ε. In both species, ε of leaves at shedding expressed as a fraction of ε in new leaves was nearly equal to RN in all years, implying that the old leaves were shed to increase canopy photosynthesis. Our results, together with those of previous field surveys, suggested that the timing of leaf shedding is explained by N use in maximizing canopy photosynthesis across broad groups of species.
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Affiliation(s)
- Tomoki Tanaka
- Graduate School of Science and Engineering, Ibaraki University, Mito, Japan
| | | | - Shimpei Oikawa
- Graduate School of Science and Engineering, Ibaraki University, Mito, Japan
- College of Science, Ibaraki University, Mito, Japan
- Institute for Global Change Adaptation Science, Ibaraki University, Mito, Japan
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Piper FI, Sepúlveda P, Bustos-Salazar A, Zúñiga-Feest A. Carbon allocation to growth and storage in two evergreen species of contrasting successional status. AMERICAN JOURNAL OF BOTANY 2017; 104:654-662. [PMID: 28490520 DOI: 10.3732/ajb.1700057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/05/2017] [Indexed: 06/07/2023]
Abstract
PREMISE OF THE STUDY A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-growing tree species in the world (Eucalyptus globulus) and a shade-tolerant, slow-growing species (Luma apiculata). METHODS Seedlings were subjected to one out of four combinations of light (high vs. low) and initial defoliation (90% defoliated vs. nondefoliated) for four months. Growth, C storage concentration in different organs, leaf shedding, and lateral shoot formation were measured at the end of the experiment. KEY RESULTS Eucalyptus globulus grew faster than L. apiculata in high light, but not in low light. Both species had lower C storage concentration in low than in high light, but similar C storage concentrations in each light condition. Defoliation had no effect on C storage, except in the case of the old leaves of both species, which showed lower C storage levels in response to defoliation. Across treatments, leaf shedding was 96% higher in E. globulus than in L. apiculata while, in contrast, lateral shoot formation was 87% higher in L. apiculata. CONCLUSIONS In low light, E. globulus prioritized C storage instead of growth, whereas L. apiculata prioritized growth and lateral branching. Our results suggest that shade tolerance depends on efficient light capture rather than C conservation traits.
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Affiliation(s)
- Frida I Piper
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Conicyt Regional R10C1003, Almirante Simpson 471, Coyhaique, Chile
- Universidad Austral de Chile, campus Patagonia, Coyhaique, Chile
| | - Paulina Sepúlveda
- Laboratorio de Biología Vegetal, Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, campus Isla Teja, Valdivia, Chile
| | - Angela Bustos-Salazar
- Laboratorio de Biología Vegetal, Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, campus Isla Teja, Valdivia, Chile
- Escuela de Graduados, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Valdivia, Chile
- Centro de Ciencia del Clima y Resiliencia (CR2), Santiago, Chile
| | - Alejandra Zúñiga-Feest
- Laboratorio de Biología Vegetal, Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, campus Isla Teja, Valdivia, Chile
- Centro de investigaciones en Suelos volcánicos (CISVo), Universidad Austral de Chile, Valdivia, Chile
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Oikawa S, Ainsworth EA. Changes in leaf area, nitrogen content and canopy photosynthesis in soybean exposed to an ozone concentration gradient. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 215:347-355. [PMID: 27261884 DOI: 10.1016/j.envpol.2016.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/01/2016] [Accepted: 05/02/2016] [Indexed: 06/05/2023]
Abstract
Influences of ozone (O3) on light-saturated rates of photosynthesis in crop leaves have been well documented. To increase our understanding of O3 effects on individual- or stand level productivity, a mechanistic understanding of factors determining canopy photosynthesis is necessary. We used a canopy model to scale photosynthesis from leaf to canopy, and analyzed the importance of canopy structural and leaf ecophysiological characteristics in determining canopy photosynthesis in soybean stands exposed to 9 concentrations of [O3] (37-116 ppb; 9-h mean). Light intensity and N content peaked in upper canopy layers, and sharply decreased through the lower canopy. Plant leaf area decreased with increasing [O3] allowing for greater light intensity to reach lower canopy levels. At the leaf level, light-saturated photosynthesis decreased and dark respiration increased with increasing [O3]. These data were used to calculate daily net canopy photosynthesis (Pc). Pc decreased with increasing [O3] with an average decrease of 10% for an increase in [O3] of 10 ppb, and which was similar to changes in above-ground dry mass production of the stands. Absolute daily net photosynthesis of lower layers was very low and thus the decrease in photosynthesis in the lower canopy caused by elevated [O3] had only minor significance for total canopy photosynthesis. Sensitivity analyses revealed that the decrease in Pc was associated with changes in leaf ecophysiology but not with decrease in leaf area. The soybean stands were very crowded, the leaves were highly mutually shaded, and sufficient light for positive carbon balance did not penetrate to lower canopy leaves, even under elevated [O3].
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Affiliation(s)
- Shimpei Oikawa
- College of Science, Ibaraki University, Mito, 310-0056, Japan; Institute for Global Change Adaptation Science, Ibaraki University, Mito, 310-0056, Japan.
| | - Elizabeth A Ainsworth
- Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana, IL, USA; Global Change and Photosynthesis Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Urbana, IL, USA
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Ogawa T, Oikawa S, Hirose T. Leaf dynamics in growth and reproduction of Xanthium canadense as influenced by stand density. ANNALS OF BOTANY 2015; 116:807-19. [PMID: 26248476 PMCID: PMC4590326 DOI: 10.1093/aob/mcv114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/05/2015] [Accepted: 06/15/2015] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Leaf longevity is controlled by the light gradient in the canopy and also by the nitrogen (N) sink strength in the plant. Stand density may influence leaf dynamics through its effects on light gradient and on plant growth and reproduction. This study tests the hypothesis that the control by the light gradient is manifested more in the vegetative period, whereas the opposite is true when the plant becomes reproductive and develops a strong N sink. METHODS Stands of Xanthium canadense were established at two densities. Emergence, growth and death of every leaf on the main stem and branches, and plant growth and N uptake were determined from germination to full senescence. Mean residence time and dry mass productivity were calculated per leaf number, leaf area, leaf mass and leaf N (collectively termed 'leaf variables') in order to analyse leaf dynamics and its effect on plant growth. KEY RESULTS Branching and reproductive activities were higher at low than at high density. Overall there was no significant difference in mean residence time of leaf variables between the two stands. However, early leaf cohorts on the main stem had a longer retention time at low density, whereas later cohorts had a longer retention time at high density. Branch leaves emerged earlier and tended to live longer at low than at high density. Leaf efficiencies, defined as carbon export per unit investment of leaf variables, were higher at low density in all leaf variables except for leaf number. CONCLUSIONS In the vegetative phase of plant growth, the light gradient strongly controls leaf longevity, whereas later the effects of branching and reproductive activities become stronger and over-rule the effect of light environment. As leaf N supports photosynthesis and also works as an N source for plant development, N use is pivotal in linking leaf dynamics with plant growth and reproduction.
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Affiliation(s)
- Takahiro Ogawa
- Department of International Agricultural Development, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Shimpei Oikawa
- Department of International Agricultural Development, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Tadaki Hirose
- Department of International Agricultural Development, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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7
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Osada N, Oikawa S, Kitajima K. Implications of life span variation within a leaf cohort for evaluation of the optimal timing of leaf shedding. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Noriyuki Osada
- Field Science, Education and Research Center Kyoto University Kyoto 606‐8502 Japan
- Tomakomai Research Station Field Science Center for Northern Biosphere Hokkaido University Tomakomai 053‐0035 Japan
| | - Shimpei Oikawa
- College of Science Ibaraki University Mito 310‐0056 Japan
| | - Kaoru Kitajima
- Graduate School of Agriculture Kyoto University Kitashirakawa Oiwake‐cho Kyoto 606‐8502 Japan
- Smithsonian Tropical Research Institute Apartado 2072 Balboa Republic of Panama
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Veneklaas EJ, Lambers H, Bragg J, Finnegan PM, Lovelock CE, Plaxton WC, Price CA, Scheible WR, Shane MW, White PJ, Raven JA. Opportunities for improving phosphorus-use efficiency in crop plants. THE NEW PHYTOLOGIST 2012; 195:306-320. [PMID: 22691045 DOI: 10.1111/j.1469-8137.2012.04190.x] [Citation(s) in RCA: 327] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Limitation of grain crop productivity by phosphorus (P) is widespread and will probably increase in the future. Enhanced P efficiency can be achieved by improved uptake of phosphate from soil (P-acquisition efficiency) and by improved productivity per unit P taken up (P-use efficiency). This review focuses on improved P-use efficiency, which can be achieved by plants that have overall lower P concentrations, and by optimal distribution and redistribution of P in the plant allowing maximum growth and biomass allocation to harvestable plant parts. Significant decreases in plant P pools may be possible, for example, through reductions of superfluous ribosomal RNA and replacement of phospholipids by sulfolipids and galactolipids. Improvements in P distribution within the plant may be possible by increased remobilization from tissues that no longer need it (e.g. senescing leaves) and reduced partitioning of P to developing grains. Such changes would prolong and enhance the productive use of P in photosynthesis and have nutritional and environmental benefits. Research considering physiological, metabolic, molecular biological, genetic and phylogenetic aspects of P-use efficiency is urgently needed to allow significant progress to be made in our understanding of this complex trait.
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Affiliation(s)
- Erik J Veneklaas
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
- Institute of Agriculture, The University of Western Australia, Crawley, WA 6009Australia
| | - Hans Lambers
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
- Institute of Agriculture, The University of Western Australia, Crawley, WA 6009Australia
| | - Jason Bragg
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Patrick M Finnegan
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
- Institute of Agriculture, The University of Western Australia, Crawley, WA 6009Australia
| | - Catherine E Lovelock
- School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - William C Plaxton
- Department of Biology and Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Charles A Price
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
| | | | - Michael W Shane
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
| | - Philip J White
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - John A Raven
- School of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
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Watari R, Nagashima H, Hirose T. Growth and nitrogen use in Xanthium canadense grown in an open or in a dense stand. PHYSIOLOGIA PLANTARUM 2012; 144:335-345. [PMID: 22211925 DOI: 10.1111/j.1399-3054.2011.01563.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Plants develop branches profusely when grown solitarily, while less so when grown in a dense stand. Such changes in architecture are associated with changes in dry mass allocation and nitrogen use. Here, we studied what traits in plant growth and nitrogen use were influenced by different light climates in the stand. Annual plants (Xanthium canadense) were grown solitarily or in a dense stand. Dry mass growth was analyzed as the product of the net assimilation rate (NAR) and leaf area (LA). Nitrogen use efficiency (NUE) was analyzed as the product of nitrogen productivity (NP) and the mean residence time (MRT) of nitrogen. These growth variables were further factorized into their components. Solitary plants maintained a high NAR, whereas plants in the dense stand decreased the NAR due to mutual shading. Plants in the dense stand developed a larger LA with a higher specific leaf area than solitary plants. Solitary plants had higher NUE due to higher NP. A temporal increase in NUE was attributed to the increase in MRT of nitrogen. Light climate was different between solitary and dense-stand plants, but they took up a comparable amount of nitrogen and used it differently in response to the given light climate. NUE was thus demonstrated to be a useful tool for analyzing the mechanism leading to different N use in plant growth.
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Affiliation(s)
- Ryoji Watari
- Department of International Agricultural Development, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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Hirose T, Oikawa S. Mean residence time of leaf number, area, mass, and nitrogen in canopy photosynthesis. Oecologia 2012; 169:927-37. [DOI: 10.1007/s00442-012-2266-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 01/19/2012] [Indexed: 11/29/2022]
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Pornon A, Marty C, Winterton P, Lamaze T. The intriguing paradox of leaf lifespan responses to nitrogen availability. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01849.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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De Boeck HJ, Dreesen FE, Janssens IA, Nijs I. Whole-system responses of experimental plant communities to climate extremes imposed in different seasons. THE NEW PHYTOLOGIST 2011; 189:806-817. [PMID: 21054412 DOI: 10.1111/j.1469-8137.2010.03515.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
• Discrete climate events such as heat waves and droughts can have a disproportionate impact on ecosystems relative to the temporal scale over which they occur. Research oriented towards (extreme) events rather than (gradual) trends is therefore urgently needed. • Here, we imposed heat waves and droughts (50-yr return time) in a full factorial design on experimental plant communities in spring, summer or autumn. Droughts were created by removing the controlled water table (rainout shelters prevented precipitation), while heat waves were imposed with infrared heaters. • Measurements of whole-system CO(2) exchange, growth and biomass production revealed multiple interactions between treatments and the season in which they occurred. Heat waves had only small and transient effects, with infrared imaging showing little heat stress because of transpirational cooling. If heat waves were combined with drought, negative effects observed in single factor drought treatments were exacerbated through intensified soil drying, and heat stress in summer. Plant recovery from stress differed, affecting the biomass yield. • In conclusion, the timing of extreme events is critical regarding their impact, and synergisms between heat waves and drought aggravate the negative effects of these extremes on plant growth and functioning.
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Affiliation(s)
- Hans J De Boeck
- Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Freja E Dreesen
- Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Ivan A Janssens
- Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Ivan Nijs
- Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium
- King Saud University, Riyadh, Saudi Arabia
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Hikosaka K, Kawauchi Y, Kurosawa T. Why does Viola hondoensis (Violaceae) shed its winter leaves in spring? AMERICAN JOURNAL OF BOTANY 2010; 97:1944-50. [PMID: 21616843 DOI: 10.3732/ajb.1000045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
PREMISE OF THE STUDY Viola hondoensis is a perennial herb that inhabits the understory of temperate, deciduous forests. It is an evergreen plant with a leaf life span that is shorter than a year. Its summer leaves are produced in spring and shed in autumn; winter leaves are produced in autumn and shed in spring. Here we asked why the plant sheds its winter leaves in spring, though climate conditions improve from spring to summer. We proposed four hypotheses for the cause of shedding: (1) changes in seasonal environment such as day length or air temperature, (2) shading by canopy deciduous trees, (3) self-shading by taller summer leaves, and (4) competition for nutrients between summer and winter leaves. • METHODS To test these hypotheses, we manipulated the environment of winter leaves: (1) plants were transplanted to the open site where there was no shading by canopy trees. (2) Petioles of summer leaves were anchored to the soil surface to avoid shading of winter leaves. (3) Sink organs were removed to eliminate nutrient competition. • KEY RESULTS Longevity of winter leaves was extended when shading by summer leaves was eliminated and when sink organs were removed, but not when plants were transplanted to the open site. • CONCLUSION We conclude that the relative difference in light availability between summer and winter leaves is a critical factor for regulation of leaf shedding, consistent with the theory of maximization of the whole-plant photosynthesis.
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Affiliation(s)
- Kouki Hikosaka
- Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan
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Marty C, Lamaze T, Pornon A. Leaf life span optimizes annual biomass production rather than plant photosynthetic capacity in an evergreen shrub. THE NEW PHYTOLOGIST 2010; 187:407-416. [PMID: 20497337 DOI: 10.1111/j.1469-8137.2010.03290.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
*Owing to nitrogen (N) translocation towards new leaves, the shedding of old leaves can increase the whole-plant carbon gain. It occurs when their photosynthetic nitrogen use efficiency (PNUE) declines below a given threshold. *Here, we investigated variations in net photosynthetic capacity (A(max)), N resorption and PNUE in populations of Rhododendron ferrugineum presenting different mean leaf life spans (LLS). *Both populations had comparable annual leaf surface area production and A(max) across leaf-age cohorts. Branch photosynthetic capacity was up to 95% higher in the population with the longer LLS mainly because of the high contribution of old leaves to the total leaf area. Despite lower N concentrations, old leaves maintained relatively high A(max) and consequently PNUE that were higher than or similar to the values found in current-year leaves. *As the ratio of PNUE in old to PNUE in new leaves was always higher than the fraction of leaf N resorbed during leaf shedding, we concluded that leaf shedding did not improve plant photosynthetic capacity. We suggest that in R. ferrugineum, leaf shedding is mainly controlled by the leaf storage function and, therefore, that models aiming to explain LLS should not only consider the leaf carbon assimilation function, particularly in nutrient-poor habitats.
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Affiliation(s)
- C Marty
- Environnement Canada, Centre Saint-Laurent, 105 rue McGill, Montréal, QC HEY 2E7, Canada
| | - T Lamaze
- Centre d'Etudes Spatiales de la Biosphère, CNES-CNRS-IRD-UMR 5639, Université Paul Sabatier, 18 Avenue Edouard Belin, bpi 2801, F-31401 Toulouse Cedex 4, France
| | - A Pornon
- Laboratoire Evolution et Diversité Biologique, CNRS-UMR 5174, Université Paul Sabatier, F-31062 Toulouse Cedex 4, France
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Yoshimura K. Irradiance heterogeneity within crown affects photosynthetic capacity and nitrogen distribution of leaves in Cedrela sinensis. PLANT, CELL & ENVIRONMENT 2010; 33:750-758. [PMID: 20519020 DOI: 10.1111/j.1365-3040.2009.02100.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Because light conditions in the forest understory are highly heterogeneous, photosynthetic acclimation to spatially variable irradiance within a crown is important for crown-level carbon assimilation. The effect of variation in irradiance within the crown on leaf nitrogen content and photosynthetic rate was examined for pinnate compound leaves in saplings of Cedrela sinensis, a pioneer deciduous tree. Five shading treatments, in which 0, 25, 50, 75 and 100% of leaves were shaded, were established by artificial heavy shading using shade screen umbrellas with 25% transmittance. Although the nitrogen content of leaves was constant regardless of shading treatment, ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco) content and light-saturated photosynthetic capacity were lower in shade leaves within partially shaded crowns than within fully shaded crowns. Shade leaves within partially shaded crowns contained higher amount of amino acids. Most shade leaves died in partially shaded crowns, whereas more than half of shade leaves survived in totally shaded crowns. Assumptions on photosynthetic acclimation to local light conditions cannot explain why shade leaves have different photosynthetic capacities and survival rates in between partially and totally shaded crowns. Irradiance heterogeneity within the crown causes a distinct variation in photosynthetic activity between sun and shaded leaves within the crown.
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Affiliation(s)
- Kenichi Yoshimura
- Graduate School of Science and Technology, Kobe University, Kobe 657-8501, Japan.
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Sala A, Piper F, Hoch G. Physiological mechanisms of drought-induced tree mortality are far from being resolved. THE NEW PHYTOLOGIST 2010; 186:274-81. [PMID: 20409184 DOI: 10.1111/j.1469-8137.2009.03167.x] [Citation(s) in RCA: 288] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
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Aguilera AG, Alpert P, Dukes JS, Harrington R. Impacts of the invasive plant Fallopia japonica (Houtt.) on plant communities and ecosystem processes. Biol Invasions 2009. [DOI: 10.1007/s10530-009-9543-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Koyama K, Kikuzawa K. Is Whole‐Plant Photosynthetic Rate Proportional to Leaf Area? A Test of Scalings and a Logistic Equation by Leaf Demography Census. Am Nat 2009; 173:640-9. [PMID: 19275491 DOI: 10.1086/597604] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Kohei Koyama
- Laboratory of Plant Ecology, Ishikawa Prefectural University, Suematsu, Nonoichi, Ishikawa 921-8836, Japan.
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