Publications by authors named "Jean-Thomas Cornelis"

10 Publications

  • Page 1 of 1

A shift from phenol to silica-based leaf defences during long-term soil and ecosystem development.

Ecol Lett 2021 May 11;24(5):984-995. Epub 2021 Mar 11.

TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium.

The resource availability hypothesis predicts that plants adapted to infertile soils have high levels of anti-herbivore leaf defences. This hypothesis has been mostly explored for secondary metabolites such as phenolics, whereas it remains underexplored for silica-based defences. We determined leaf concentrations of total phenols and silicon (Si) in plants growing along the 2-million-year Jurien Bay chronosequence, exhibiting an extreme gradient of soil fertility. We found that nitrogen (N) limitation on young soils led to a greater expression of phenol-based defences, whereas old, phosphorus (P)-impoverished soils favoured silica-based defences. Both defence types were negatively correlated at the community and individual species level. Our results suggest a trade-off among these two leaf defence strategies based on the strength and type of nutrient limitation, thereby opening up new perspectives for the resource availability hypothesis and plant defence research. This study also highlights the importance of silica-based defences under low P supply.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ele.13713DOI Listing
May 2021

Combined Silicon-Phosphorus Fertilization Affects the Biomass and Phytolith Stock of Rice Plants.

Front Plant Sci 2020 18;11:67. Epub 2020 Feb 18.

Soil Science, Earth and Life Institute, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium.

Phytoliths are silica bodies formed in living plant tissues. Once deposited in soils through plant debris, they can readily dissolve and then increase the fluxes of silicon (Si) toward plants and/or watersheds. These fluxes enhance Si ecological services in agricultural and marine ecosystems through their impact on plant health and carbon fixation by diatoms, respectively. Fertilization increases crop biomass through the supply of plant nutrients, and thus may enhance Si accumulation in plant biomass. Si and phosphorus (P) fertilization enhance rice crop biomass, but their combined impact on Si accumulation in plants is poorly known. Here, we study the impact of combined Si-P fertilization on the production of phytoliths in rice plants. The combination of the respective supplies of 0.52 g Si kg and 0.20 g P kg generated the largest increase in plant shoot biomass (leaf, flag leaf, stem, and sheath), resulting in a 1.3-fold increase compared the control group. Applying combined Si-P fertilizer did not affect the content of organic carbon (OC) in phytoliths. However, it increased plant available Si in soil, plant phytolith content and its total stock (mg phytolith pot) in dry plant matter, leading to the increase of the total amount of OC within plants. In addition, P supply increased rice biomass and grain yield. Through these positive effects, combined Si-P fertilization may thus address agronomic (e.g., sustainable ecosystem development) and environmental (e.g., climate change) issues through the increase in crop yield and phytolith production as well as the promotion of Si ecological services and OC accumulation within phytoliths.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpls.2020.00067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7040097PMC
February 2020

Contribution of agroecological farming systems to the delivery of ecosystem services.

J Environ Manage 2020 Apr 9;260:109576. Epub 2020 Feb 9.

Biodiversity and Landscapes Unit, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, 5030, Gembloux, Belgium.

Agroecology has been suggested as a promising concept for reconciling agricultural production and environmental sustainability by optimizing ecological processes that deliver ecosystem services (ES) to replace external inputs. While this statement is widely agreed upon, few assessments of real-life conditions exist that assess multiple ES simultaneously. This paper provides an assessment of seven ES based on 14 indicators in three agroecological farming systems (AFS) and thirteen of their adjacent conventional farming systems (CFS). Based on field-scale measurements spread over three years, our findings suggest that the studied AFS succeed in providing a wider array of regulating services than their neighboring CFS. Soil aggregate stability and soil respiration rates are in general more supported in AFS, which also show lower pest abundance. On the other hand, CFS show higher grain production and higher performance for two out of three fodder quality indices. While this 'productivity gap' may be due to the still-evolving state of the studied AFS, we nuance this through the lens of an emerging paradigm to assess farming system multi-performance. It is now argued that we need to shift from a volume-focused production system to a system that also values the ecological processes underpinning crop production and other benefits to society. Based on our findings, we recommend future work to iterate our initiative, including several indicators per service and embed these into a wider context of co-adaptive science-practice to further develop context-specific and user-useful research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jenvman.2019.109576DOI Listing
April 2020

Comparative analysis of borate fusion versus sodium carbonate extraction for quantification of silicon contents in plants.

J Plant Res 2020 Mar 2;133(2):271-277. Epub 2020 Jan 2.

Graduate School of Agriculture, Kyoto University, Kyoto, Japan.

Studies of plant-silicon (Si) interaction benefit from safe, affordable and accurate methods to measure acid-insoluble silica (phytoliths) for a large number of plant samples. This study aimed to evaluate the comparability between two chemical methods to dissolve leaf silica, borate fusion and 1% sodium carbonate (NaCO) extraction, in combination of two detection methods (ICP, molybdenum-blue colorimetry).We compared the results obtained by these methods, using dried leaf samples of five tropical tree species that differ widely in Si concentrations (4 to 100 mg g DW). Leaf Si concentration values determined after the two extraction methods were highly correlated (y = 0.79x, R = 0.998). However, compared to the extraction with borate fusion, the 1% NaCO method resulted in lower Si concentration per unit dry mass by 16% to 32% (mean of 24.2%). We also found that molybdenum-blue colorimetry method may interfere with certain extraction methods. A simple equation can be used to correct for systematic underestimation of Si contents determined after extraction with 1% NaCO, which is the least expensive and safest among commonly used methods for extraction of Si from land plants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10265-019-01162-2DOI Listing
March 2020

Silicon and Plant Natural Defenses against Insect Pests: Impact on Plant Volatile Organic Compounds and Cascade Effects on Multitrophic Interactions.

Plants (Basel) 2019 Oct 23;8(11). Epub 2019 Oct 23.

Gembloux Agro-Bio Tech, TERRA, University of Liège, Avenue de la Faculté d'Agronomie 2, 5030 Gembloux, Belgium.

Environmental factors controlling silicon (Si) accumulation in terrestrial plant are key drivers to alleviate plant biotic stresses, including insect herbivory. While there is a general agreement on the ability of Si-enriched plant to better resist insect feeding, recent studies suggest that Si also primes biochemical defense pathways in various plant families. In this review, we first summarize how soil parameters and climate variables influence Si assimilation in plants. Then, we describe recent evidences on the ability of Si to modulate plant volatile emissions, with potential cascade effects on phytophagous insects and higher trophic levels. Even though the mechanisms still need to be elucidated, Si accumulation in plants leads to contrasting effects on the levels of the three major phytohormones, namely jasmonic acid, salicylic acid and ethylene, resulting in modified emissions of plant volatile organic compounds. Herbivore-induced plant volatiles would be particularly impacted by Si concentration in plant tissues, resulting in a cascade effect on the attraction of natural enemies of pests, known to locate their prey or hosts based on plant volatile cues. Since seven of the top 10 most important crops in the world are Si-accumulating Poaceae species, it is important to discuss the potential of Si mobility in soil-plant systems as a novel component of an integrated pest management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/plants8110444DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6918431PMC
October 2019

Management of Grassland-like Wildflower Strips Sown on Nutrient-rich Arable Soils: The Role of Grass Density and Mowing Regime.

Environ Manage 2019 05 13;63(5):647-657. Epub 2019 Mar 13.

Gembloux Agro-Bio Tech, Biodiversity and landscape Unit, University of Liege, Passage des Déportés 2, Gembloux, 5030, Belgium.

Wildflower strips (WS) are proposed in many European countries as a strategy to enhance biodiversity and ecosystem services in arable fields. To create and maintain WS on nutrient-rich cultivated soils reveals challenging. Flowered species may be outcompeted by grasses due to high phosphorus content in soil. We studied during 5 years seed mixture (grass density in the seed mix) and mowing regime influenced the ability of WS to provide environmental benefits (flower provision for insects and landscape purposes, reduction of soil nutrient load) and respond to farmer concerns (noxious weed promotion, forage production). Lowered grass density increased flower abundance, but not diversity, only in the first 3 years. In the last 2 years mowing effects became determinant. Flower cover and richness were the highest under the twice-a-year mowing regime. This regime also increased forage quantity and quality. Flower colour diversity was conversely the highest where mowing occurred every two years. Potassium in the soil decreased under the twice-a-year mowing regime. Other nutrients were not affected. No management option kept noxious weed to an acceptable level after 5 years. This supports the need to test the efficacy of specific management practices such as selective clipping or spraying. Mowing WS twice a year was retained as the most favourable treatment to maintain species-rich strips with an abundant flower provision. It however implies to mow in late June, i.e. at the peak of insect abundance. It is therefore suggested to keep an unmown refuge zone when applying this management regime.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00267-019-01153-yDOI Listing
May 2019

Experimental evidence of large changes in terrestrial chlorine cycling following altered tree species composition.

Environ Sci Technol 2015 Apr 1;49(8):4921-8. Epub 2015 Apr 1.

†Department of Thematic Studies-Environmental Change, Linköping University, SE-581 83, Linköping, Sweden.

Organochlorine molecules (Clorg) are surprisingly abundant in soils and frequently exceed chloride (Cl(-)) levels. Despite the widespread abundance of Clorg and the common ability of microorganisms to produce Clorg, we lack fundamental knowledge about how overall chlorine cycling is regulated in forested ecosystems. Here we present data from a long-term reforestation experiment where native forest was cleared and replaced with five different tree species. Our results show that the abundance and residence times of Cl(-) and Clorg after 30 years were highly dependent on which tree species were planted on the nearby plots. Average Cl(-) and Clorg content in soil humus were higher, at experimental plots with coniferous trees than in those with deciduous trees. Plots with Norway spruce had the highest net accumulation of Cl(-) and Clorg over the experiment period, and showed a 10 and 4 times higher Cl(-) and Clorg storage (kg ha(-1)) in the biomass, respectively, and 7 and 9 times higher storage of Cl(-) and Clorg in the soil humus layer, compared to plots with oak. The results can explain why local soil chlorine levels are frequently independent of atmospheric deposition, and provide opportunities for improved modeling of chlorine distribution and cycling in terrestrial ecosystems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.5b00137DOI Listing
April 2015

Landscape cultivation alters δ³⁰Si signature in terrestrial ecosystems.

Sci Rep 2015 Jan 13;5:7732. Epub 2015 Jan 13.

Department of Biology, Research Group Ecosystem Management, University of Antwerp, Wilrijk, Belgium.

Despite increasing recognition of the relevance of biological cycling for Si cycling in ecosystems and for Si export from soils to fluvial systems, effects of human cultivation on the Si cycle are still relatively understudied. Here we examined stable Si isotope (δ(30)Si) signatures in soil water samples across a temperate land use gradient. We show that - independent of geological and climatological variation - there is a depletion in light isotopes in soil water of intensive croplands and managed grasslands relative to native forests. Furthermore, our data suggest a divergence in δ(30)Si signatures along the land use change gradient, highlighting the imprint of vegetation cover, human cultivation and intensity of disturbance on δ(30)Si patterns, on top of more conventionally acknowledged drivers (i.e. mineralogy and climate).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep07732DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291558PMC
January 2015

Impact of rice cultivar and organ on elemental composition of phytoliths and the release of bio-available silicon.

Front Plant Sci 2014 10;5:529. Epub 2014 Oct 10.

Soil Science and Environment Geochemistry, Earth and Life Institute, Université Catholique de Louvain Louvain-la-Neuve, Belgium.

The continental bio-cycling of silicon (Si) plays a key role in global Si cycle and as such partly controls global carbon (C) budget through nutrition of marine and terrestrial biota, accumulation of phytolith-occluded organic carbon (PhytOC) and weathering of silicate minerals. Despite the key role of elemental composition of phytoliths on their solubility in soils, the impact of plant cultivar and organ on the elemental composition of phytoliths in Si high-accumulator plants, such as rice (Oryza sativa) is not yet fully understood. Here we show that rice cultivar significantly impacts the elemental composition of phytoliths (Si, Al, Fe, and C) in different organs of the shoot system (grains, sheath, leaf and stem). The amount of occluded OC within phytoliths is affected by contents of Si, Al, and Fe in plants, while independent of the element composition of phytoliths. Our data document, for different cultivars, higher bio-available Si release from phytoliths of leaves and sheaths, which are characterized by higher enrichment with Al and Fe (i.e., lower Si/Al and Si/Fe ratios), compared to grains and stems. We indicate that phytolith solubility in soils may be controlled by rice cultivar and type of organs. Our results highlight that the role of the morphology, the hydration rate and the chemical composition in the solubility of phytoliths and the kinetic release of Si in soil solution needs to be studied further. This is central to a better understanding of the impact of soil amendment with different plant organs and cultivars on soil OC stock and on the delivery of dissolved Si as we show that sheath and leaf rice organs are both characterized by higher content of OC occluded in phytolith and higher phytolith solubility compared to grains and stems. Our study shows the importance of studying the impact of the agro-management on the evolution of sinks and sources of Si and C in soils used for Si-high accumulator plants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpls.2014.00529DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4193235PMC
October 2014