DS0101 - Comprendre et prévoir les évolutions de l'environnement

Deciphering sYmbiotic Networks in cArob-based MedIterranean agro-eCosystems – DYNAMIC

Deciphering symbiotic networks in carob-based Mediterranean agro-ecosystems

DYNAMIC should give new insights on the ecological drivers governing host-symbiont specificity and efficiency and propose new avenues for efficient ecological engineering strategies applied to ecosystem restoration and ecological intensification of (agro)ecosystems.

Understand the past to elaborate a sustainable future

DYNAMIC will contribute to fill knowledge gaps in the ecology of carob symbiotic associations (basic research) to propose new avenues for the development of efficient ecological engineering strategies applied to ecosystem restoration and ecological intensification of agro-ecosystems (applied research). Objectives - Characterizing carob genetic diversity at the Mediterranean scale by revealing evolutionary significant units - Characterizing carob-symbiotic microbiome - Deciphering ecological networks in carob-based (agro)ecosystems to identify the drivers of alpha and beta symbiotic microbiome diversity. - Evaluating artificial symbiotic networks on carob growth - Drawing up recommendations for ecological engineering based on host-symbiont specific interactions. Impact - Provide new avenues in conservation and ecological intensification of Mediterranean (agro)ecosystems, and more generally in forestry, ecosystem and landscape, plant ecology, microbial ecology and molecular ecology. - In agreement with the need to set up multidisciplinary researches linking biology and informatics in order to develop integrative sciences. - Deeply complementary of national and European initiatives aiming at the ecological intensification of (agro)ecosystems and biodiversity conservation in Mediterranean countries. - Strongly in line with the scientific strategy of French research institutes (Cirad, IRD, and University) for the development of researches and formations in conservation and ecological intensification of (agro)ecosystems in Europe and more particularly in South countries

Task 1 - Coordination, Networking and Dissemination The task 1 covers all the coordination activities and related project management: organization, planning and control of the workplan, contractual issues, project meetings, reports, and project outputs. Task 2 - Characterization and Selection of carob-based (agro)ecosystems The task 2 deals with the survey of carob-based (agro)ecosystems and the selection of study sites in seven different countries in Europe (Italy, France, Spain), Maghreb (Morocco, Tunisia) and Near East (Cyprus, Lebanon) Task 3 - Carob genetic diversity The task 3 deals with the evolutionary history, geographical genetic structure and genetic diversity of carob populations at the Mediterranean scale Task 4 - Symbiotic microbiome diversity The task 4 aims at characterizing the symbiotic microbiome diversity associated with carob populations across the Mediterranean countries by combining NGS technologies and traditional approaches Task 5 - Ecological and symbiotic networks The task 5 deals with the integration of genetic (plant, microbiome) and environmental data for network analyses Task 6 - Ecological engineering and artificial symbiotic networks The task 6 consists in the experimental evaluation of artificial symbiotic network performances on carob growth (controlled conditions)

In progress

Improve and develop innovative researches for an efficient resource management and adaptation to global change.

Publication in journal with reading commitee (4)
1. Baumel et al 2018. Plant Ecology and Evolution, 151(2): 185-193.
2. Di Guardo et al. 2019. Tree Genetics & Genomes 15: 41.
3. Manaut et al. 2015. Ecological Engineering, 79:113-119. <br

Mediterranean terrestrial ecosystems are facing increasing desertification because of the worsening of environmental pressures due to global change. The desertification processes lead to plant cover degradation, soil erosion, nutrient depletion and a decrease of microbial activity. The establishment of global political strategies aiming at a better management of terrestrial ecosystems is thus crucial for their conservation. In this context, Ceratonia siliqua L. (carob tree), a xerophilous tree adapted to Mediterranean climate, appears as a key model for afforestation/restoration programs because of its resistance and adaptation to extreme environmental conditions and its high socio-economic added value.

Carob is a non-nodulated legume highly dependent of arbuscular mycorrhizal (AM) symbiosis for its survival and productivity. Its biological nitrogen fixation status remains uncertain but AM fungi have been hypothesized as an "obligatory vector" of nitrogen-fixing endophytic bacteria into the carob intracellular compartment. The management of carob populations is therefore closely linked to a better understanding and use (ecological engineering strategies) of the symbiotic community associated with carob.

The main hypothesis of DYNAMIC is that infra-specific plant evolutionary differentiation is a determinant, but overlooked, driver of the diversity and structure of the symbiotic community, optimizing symbiotic efficiency. However, the evolutionary history and genetic diversity structure of carob is mostly unknown at the Mediterranean scale. Geographical isolation, long term vicariance and selection for agriculture are expected to have caused extensive genetic and physiological modifications in carob, conducing to potential changes/adaptations of its associated symbiotic microbiome. The overall objective of DYNAMIC is to decipher the symbiotic network in Mediterranean carob-based (agro)ecosytems to develop innovative ecological strategies based on efficient symbiotic interactions.

The project is tackling this issue by (i) revealing the evolutionary significant units and genetic structure of carob at the Mediterranean scale, (ii) characterizing the alpha and beta taxonomic and phylogenetic diversity of carob symbiotic microbiome, (iii) exploring the links between these genetic parameters and environmental data to determine symbiotic networks and their drivers (genetic x ecological) and finally by (iv) testing experimentally the results to optimize the host-symbiont efficiency in carob tree cultures. Field investigations will be done through the carob dissemination history (native and exotic areas) and in contrasting ecological contexts (shrublands, agroforestry systems, pure stands). The symbiotic networks will be characterized by combining high-throughput molecular approaches, bioinformatic analyses based on ecological network theory, and then applied to develop innovative ecological engineering strategies.

The perspectives are a better understanding of plant-microbiome genetic relationships driving ecosystem functioning and the identification of a core and an accessory "SymbiOme" in carob populations. More generally, DYNAMIC should give new insights on the ecological drivers governing host-symbiont specificity and efficiency and should propose new avenues for the development of efficient ecological engineering strategies applied to ecosystem restoration and ecological intensification of (agro)ecosystems.

Project coordinator

Monsieur Herve Sanguin (Laboratoire des Symbioses Tropicales et Méditerranéennes)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.

Partner

University Saint Joseph University Saint Joseph
L2E - UCAM Laboratory of Ecology and Environment - University of Cadi Ayyad of Marrakesh
University of Catania University of Catania
IMBE Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale
LSTM Laboratoire des Symbioses Tropicales et Méditerranéennes

Help of the ANR 484,200 euros
Beginning and duration of the scientific project: September 2014 - 42 Months

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