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Individual variability in plants: From intra- to inter-individual variability and its response to the environment
No full textInternational audienceIndividual variability refers to the differences observed among genetically identical plants or cells grown in the same environment. Phenotypic and transcriptional variability have been extensively described in unicellular organisms and mammalian cells. However, increasing evidence now points to both intra-and inter-individual variability in plants. Cell-to-cell variability in gene expression within a single plant (intra-individual variability) is now recognised as a key factor contributing to the robustness of plant development as well as environmental responses. At a broader scale, multiple studies strongly suggest that inter-individual variability, often involving gene expression differences between individual seedlings, can be associated with an adaptive value at the population level under challenging environmental conditions. This review first aims to describe what is currently known about intra-and inter-individual variability in plants, with a main focus on gene expression variation and highlighting the importance of chromatin modifications. We then illustrate how the extent of individual variability can differ depending on environmental conditions, and discuss how the plasticity of such variability may enhance the ability of plants to respond to challenging situations. These observations finally underline the relevance of investigating individual variability in the context of agriculture
Enhancing environmental models with a new downscaling method for global radiation in complex terrain
No full textInternational audienceGlobal radiation is a key climate input in process-based models (PBMs) for forests, as it determines photosynthesis, transpiration and the canopy energy balance. While radiation is highly variable at a fine spatial resolution in complex terrain due to shadowing effects, the data required for PBMs that are currently available over large extents are generally at a spatial resolution coarser than ∼9 km. Downscaling large-scale radiation data to the high resolution available from digital elevation models (DEMs) is therefore of potential importance to refine global radiation estimates and improve PBM estimations. In this study, we introduced a new downscaling model that aims to refine sub-daily global radiation data obtained from climate reanalysis data or projections at large scales to the resolution of a given DEM. First, downscaling involves splitting radiation into a direct and diffuse fraction. The influences of surrounding mountains' shade on direct radiation and the “bowl” (deep valley) effect (or sky-view factor) on diffuse radiation are then considered. The model was evaluated by comparing simulated and observed radiation at the Mont Ventoux study site (southeast of France) using the recent ERA5-Land hourly data available at a 9 km resolution as input and downscaled to different spatial resolutions (from 1 km to 30 m resolution) using a DEM. The downscaling algorithm improved the reliability of radiation at the study site, in particular at scales below 150 m. Finally, by using two different PBMs (CASTANEA, a PBM simulating tree growth, and SurEau, a plant hydraulic model simulating hydraulic failure risk), we showed that accounting for fine-resolution radiation can have a great impact on predictions of forest functions
Does artificial light interfere with the activity of nocturnal mammals? An experimental study using road underpasses
No full textInternational audienceThe emission of artificial light at night (ALAN) generates a light pollution. The impacts on fauna, flora and ecosystems have been increasingly studied in recent decades. However, mammals - except bats or rodents - remain under-studied, particularly in terms of space use. Here, we implemented a three-year in-situ before–during–after exposure protocol to assess the effect of artificial light at night at five underpasses of a motorway in a French regional natural park. Using camera traps, we recorded movements of medium-sized wild mammals and collected data on 12 species, especially European badger Meles meles, red fox Vulpes vulpes and martens (Martes martes and M. foina). Our results showed that lighting significantly decreased the probability to cross the underpasses for European badger in spring and autumn and for red fox in spring, while there was no significant effect of lighting for martens. Lighting also reduced crossing speed for badgers. We can conclude that, for some medium-sized wild mammals, ALAN triggers an avoidance behaviour that prevents them from crossing lit underpasses during certain seasons. This suggests that ALAN can act as a nightscape fragmentation, which is in line with previous studies on other taxa - as bats, insects, amphibians or eels. This additional barrier effect confirms the value of dark infrastructure; i.e. ecological network policies to preserve dark habitat patches and dark corridors
Environmental Tax Competition and Welfare: The Good News about Lobbies
No full textInternational audienceThis paper focuses on the welfare effects of domestic and international lobbying in the context of two countries linked by both trade and pollution. We consider a reciprocal-markets model where, in each country, a domestic firm produces a polluting good, that can result in a cross-national environmental externality, and competes in quantities in each market with a foreign firm. Each government independently sets a pollution tax under political pressure from green and industrial lobbies à la Grossman and Helpman (1994). Our results mainly show that political pressure from domestic and/or international lobbies can help mitigate taxcompetition between the two countries, resulting in an improvement in social welfare. In fact, lobbying acts much like a strategic delegation device by changing the social welfare weights in the objective function of each government. The (potential) welfare-improving effect of political pressure depends on the relative strengths of the lobbies and on the nature of the strategic interactions in taxes
Chapter 10 - Use of arrowroot (Maranta arundinacea L.) and canna (Canna edulis Ker) for the formulation of products, including baked and confectionery staple goods
No full textInternational audienceMaranta arundinacea L. and Canna edulis Ker are rhizomatous plants originally growing from the Andean region exhibiting an attractive edible yield. Like roots and tubers, these plants are staples contributing to food security due to their pivotal role in the human diet. These plants are also climate-resilient. Known for their ability to grow on marginal and less productive lands, maranta and canna contribute to biodiversity. Also known to being perishable, both rhizomatous plants exhibit high losses during postharvest. According to their respective composition, both resources could be used as functional utilities to produce nonperishable intermediate flour and starch products to later formulate goods. Given their complementary physicochemical and functional properties, both plants seem attractive for the food industry and in particular for baked goods, confectionery, and edible films. After a comparison of some physical, compositional, and functional traits between both species, this chapter provides an overview of initiatives in research for starch and flour confectionery using arrowroot and canna resources, with emphasis toward baked products
Prevention and management of plant protection product transfers within the environment: A review
No full textInternational audienceThe intensification of agriculture has promoted the simplification and specialization of agroecosystems, resulting in negative impacts such as decreasing landscape heterogeneity and increasing use of plant protection products (PPP), with the acceleration of PPP transfers to environmental compartments and loss in biodiversity. In this context, the present work reviews the various levers for action promoting the prevention and management of these transfers in the environment and the available modelling tools. Two main categories of levers were identified: (1) better control of the application, including the reduction of doses and of PPP dispersion during application thanks to appropriate equipment and settings, PPP formulations, and consideration of meteorological conditions; (2) reduction of post-application transfers at plot scales (soil cover, low tillage, organic matter management, remediation…) and at landscape scales using either dry (grassed strips, forest, hedgerows, ditches) or wet (ponds, mangroves, stormwater basins) buffer zones. The management of PPP residues leftover in the spray tanks (biobeds) also represents a lever for limiting point-source PPP pollution. Numerous models have been developed to simulate the transfers of PPPs at plot scales. They are scarce for landscape scales. A few are used for regulatory risk assessment. These models could still be improved, for example, if current agricultural practices (e.g. agroecological practices, biopesticides), and their effect on PPP transfers, were better described. If operated alone, none of the levers guarantee a zero risk of PPP transfer. However, if levers are applied in a combined manner, PPP transfers could be more easily limited (agricultural practices, landscape organization...)
Epidémiologie, diversité génétique et caractérisation pathogénique du maize streak virus dans les champs de riz au Burkina Faso
No full textInternational audienceRice is of critical significance regarding food security worldwide including in Africa. Only two viruses impacting rice production in Africa have been deeply investigated for decades: the rice yellow mottle virus (Solemoviridae) and the rice stripe necrosis virus (Benyviridae). Using viral metagenomics, we aimed at broadening knowledge on interacting communities associated with plants in rice landscapes and exploring the diversity and the epidemiological status of viruses circulating in rice fields from Burkina Faso. We performed an epidemiological survey in this country between 2016 and 2019 involving 57 small farmer’s rice fields under two production systems (rainfed lowlands and irrigated areas). More than 2700 rice samples were collected without regard for disease symptoms following a regular scheme. In addition, wild and cultivated (maize and sugarcane) Poaceae growing nearby rice fields were also collected. Unexpectedly, metagenomics detected maize streak virus (MSV, Geminiviridae) in analyzed rice samples. Further molecular analyses using RCA-PCR showed that MSV is widely distributed and highly prevalent in both rainfed lowlands and irrigated rice areas. MSV-A and MSV-G strains were identified. MSV-G, exclusively identified so far in wild grasses, was the most prevalent strain while MSV-A, known to cause severe symptoms in maize, was sporadically identified. Using infectious clones in experimental conditions, we confirmed the pathogenicity of both MSV strains on rice. Thus, in addition to contributing to the epidemiological surveillance of rice production in Africa, our results illuminate new epidemiological and pathogenic aspects of one of the most studied plant viruses with significant economic consequences in Africa
Questionnaire d'enquête "Ménage agricole": Évaluation et chiffrage du rôle socio-économique, culturel et autre des femmes dans les petites et moyennes exploitations agricole du sud du Maroc
No full textQuestionnaire d'enquête relatif au rôle des femmes dans les petites et moyennes exploitations agricoles du sud du Maroc (2018)Nowadays, women's contribution to society through their social and human involvement at the household level in terms of education, care, and nutrition, as well as their added value to economic functioning, is increasingly recognized. However, most of the related research highlights the relative contributions of women and men. In this paper, we proposed to analyze the link between women's contribution to social, economic, and financial activities and the rural livelihood of the whole household farm. Based on a household survey that included a women respondent section of over 285 families in the most vulnerable regions of Morocco, we used descriptive statistics and systemic analysis successively based on multiple factorial and clustering analyses to analyze the links between household adaptative capacity and women's material and immaterial contributions. The results revealed that women play a crucial role in intergenerational knowledge transfer, which constitutes a critical factor in household capacities and reproduction, especially in the least endowed households. However, the women's farm or off-farm activities did not guarantee their autonomy. So, the contribution of women to household farm livelihood through their know-how opens alternative pathways to reconsider their contribution to the overall goal of livelihood improvement
Journey to the past: molecular de-extinction enables the discovery of ancient β-defensins and highlights their evolutionary history
No full textInternational audienceMolecular de-extinction is an innovative science aiming to discover, synthesize, and characterize molecules throughout evolution. Recent work by Ferreira et al. involved mining ancient genomes to search for antimicrobial defensins. They discovered six ancient β-defensins, revealing their evolutionary history and uncovering their structural and biochemical properties, which could feed medical applications
New insights on the evolution of processionary moths (Thaumetopoea spp., Lepidoptera, Notodontidae) based on a RAD‐seq phylogeny
No full textThe obtained sequence data are available in GenBank, with accession numbers PP796445-PP796475. The RAD-seq alignments were deposited in the French institutional repository data.gouv.fr and can be retrieved freely at: https://doi.org/10.57745/B1MHWD.International audienceThaumetopoea is a genus of Lepidoptera referred to as the processionary moths species, that comprises famous defoliators of forest trees. They are also a threat to human and animal health due to the urticating setae carried by their larvae. Their phylogenetic relationships were studied so far using morphological data, mitochondrial DNA and only a few nuclear markers. Results remained controversial so far, notably for the winter Conifer‐feeding species complex encompassing T. pityocampa and T. wilkinsoni. In particular, since the first identification of divergent mitochondrial clades, several new species were described and incongruent phylogenies were proposed in this group. We here explored the potential of nuclear RAD‐seq data to resolve these inconsistencies and compare the resultant phylogeny with the information provided by the mitochondrial COI gene. It allows to propose a robust phylogeny and decipher cases of mitochondrial introgressions and nuclear‐mitochondrial discordance, which raises doubts about the validity of some recently described species. Hence, we recommend caution before describing new taxa in this group from mitochondrial data alone. Species delineation between geographically bounded and genetically differentiated lineages cannot be addressed pertinently without dedicated sampling and associated population genomic and ecological studies