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Thorne SJ, Maathuis FJM, Hartley SE. Induction of silicon defences in wheat landraces is local, not systemic, and driven by mobilization of soluble silicon to damaged leaves. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5363-5373. [PMID: 37314063 DOI: 10.1093/jxb/erad224] [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: 05/03/2023] [Accepted: 06/13/2023] [Indexed: 06/15/2023]
Abstract
In response to herbivory, many grasses, including crops such as wheat, accumulate significant levels of silicon (Si) as an antiherbivore defence. Damage-induced increases in Si can be localized in damaged leaves or be more systemic, but the mechanisms leading to these differences in Si distribution remain untested. Ten genetically diverse wheat landraces (Triticum aestivum) were used to assess genotypic variation in Si induction in response to mechanical damage and how this was affected by exogenous Si supply. Total and soluble Si levels were measured in damaged and undamaged leaves as well as in the phloem to test how Si was allocated to different parts of the plant after damage. Localized, but not systemic, induction of Si defences occurred, and was more pronounced when plants had supplemental Si. Damaged plants had significant increases in Si concentration in their damaged leaves, while the Si concentration in undamaged leaves decreased, such that there was no difference in the average Si concentration of damaged and undamaged plants. The increased Si in damaged leaves was due to the redirection of soluble Si, present in the phloem, from undamaged to damaged plant parts, potentially a more cost-effective defence mechanism for plants than increased Si uptake.
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Affiliation(s)
- Sarah J Thorne
- Plants, Photosynthesis, and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
| | | | - Susan E Hartley
- Plants, Photosynthesis, and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
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de Tombeur F, Raven JA, Toussaint A, Lambers H, Cooke J, Hartley SE, Johnson SN, Coq S, Katz O, Schaller J, Violle C. Why do plants silicify? Trends Ecol Evol 2023; 38:275-288. [PMID: 36428125 DOI: 10.1016/j.tree.2022.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/30/2022] [Accepted: 11/02/2022] [Indexed: 11/24/2022]
Abstract
Despite seminal papers that stress the significance of silicon (Si) in plant biology and ecology, most studies focus on manipulations of Si supply and mitigation of stresses. The ecological significance of Si varies with different levels of biological organization, and remains hard to capture. We show that the costs of Si accumulation are greater than is currently acknowledged, and discuss potential links between Si and fitness components (growth, survival, reproduction), environment, and ecosystem functioning. We suggest that Si is more important in trait-based ecology than is currently recognized. Si potentially plays a significant role in many aspects of plant ecology, but knowledge gaps prevent us from understanding its possible contribution to the success of some clades and the expansion of specific biomes.
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Affiliation(s)
- Félix de Tombeur
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France; School of Biological Sciences and Institute of Agriculture, The University of Western Australia, Perth, Australia.
| | - John A Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, UK; School of Biological Sciences, The University of Western Australia, Perth, Australia; Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, Australia
| | - Aurèle Toussaint
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Hans Lambers
- School of Biological Sciences and Institute of Agriculture, The University of Western Australia, Perth, Australia
| | - Julia Cooke
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Sue E Hartley
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Scott N Johnson
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, Australia
| | - Sylvain Coq
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Ofir Katz
- Dead Sea and Arava Science Center, Mount Masada, Tamar Regional Council, Israel; Eilat Campus, Ben-Gurion University of the Negev, Eilat, Israel
| | - Jörg Schaller
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - Cyrille Violle
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
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de Tombeur F, Lemoine T, Violle C, Fréville H, Thorne S, Hartley SE, Lambers H, Fort F. Nitrogen availability and plant-plant interactions drive leaf silicon concentration in wheat genotypes. Funct Ecol 2022; 36:2833-2844. [PMID: 36606113 PMCID: PMC9804457 DOI: 10.1111/1365-2435.14170] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/06/2022] [Indexed: 01/09/2023]
Abstract
Estimating plasticity of leaf silicon (Si) in response to abiotic and biotic factors underpins our comprehension of plant defences and stress resistance in natural and agroecosystems. However, how nitrogen (N) addition and intraspecific plant-plant interactions affect Si concentration remains unclear.We grew 19 durum wheat genotypes (Triticum turgidum ssp. durum) in pots, either alone or in intra- or intergenotypic cultures of two individuals, and with or without N. Above-ground biomass, plant height and leaf [Si] were quantified at the beginning of the flowering stage.Nitrogen addition decreased leaf [Si] for most genotypes, proportionally to the biomass increase. Si plasticity to plant-plant interactions varied significantly among genotypes, with both increases and decreases in leaf [Si] when mixed with a neighbour, regardless of the mixture type (intra-/intergenotype). Besides, increased leaf [Si] in response to plant-plant interactions was associated with increased plant height.Our results suggest the occurrence of both facilitation and competition for Si uptake from the rhizosphere in wheat mixtures. Future research should identify which leaf and root traits characterise facilitating neighbours for Si acquisition. We also show that Si could be involved in height gain in response to intraspecific competition, possibly for increasing light capture. This important finding opens up new research directions on Si and plant-plant interactions in both natural ecosystems and agroecosystems. More generally, our results stress the need to explore leaf Si plasticity in responses to both abiotic and biotic factors to understand plant stress resistance. Read the free Plain Language Summary for this article on the Journal blog.
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Affiliation(s)
- Felix de Tombeur
- CEFE, Univ Montpellier, CNRS, EPHE, IRDMontpellierFrance,School of Biological Sciences and Institute of AgricultureThe University of Western AustraliaPerthWAAustralia
| | - Taïna Lemoine
- CEFE, Univ Montpellier, CNRS, EPHE, IRDMontpellierFrance,AGAP, Univ Montpellier, CIRAD, INRAE, Institut AgroMontpellierFrance
| | - Cyrille Violle
- CEFE, Univ Montpellier, CNRS, EPHE, IRDMontpellierFrance
| | - Hélène Fréville
- AGAP, Univ Montpellier, CIRAD, INRAE, Institut AgroMontpellierFrance
| | - Sarah J. Thorne
- Department of BiologyUniversity of YorkYorkUK,School of BiosciencesUniversity of SheffieldSheffieldUK
| | | | - Hans Lambers
- School of Biological Sciences and Institute of AgricultureThe University of Western AustraliaPerthWAAustralia
| | - Florian Fort
- CEFE, Univ. Montpellier, L'Institut agro, CNRS, EPHE, IRDMontpellierFrance
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