Judith LEGRAND

Biomathematics and biostatistics

     
  • plant
  • biotic
  • interactions,
  • mathematical
  • models,
  • plant-pest
  • interactions

 Université Paris-Saclay, Maitre de conférences

 judith.legrand@inrae.fr —   +33 (0)1 69 33 23 49


 Biologie de l'Adaptation et Systèmes en Évolution

Implication de Judith Legrand dans axe1 20% axe1 Understanding and shedding light on evolutionary mecanisms Axe1 Implication de Judith Legrand dans axe2 50% axe2 Understanding and predicting the genetic bases of interactions Axe2 Implication de Judith Legrand dans axe3 30% axe3 Understanding and mobilizing cultivated diversity to provide solutions for agriculture and its actors Axe3
 Publications    

  • Génétique Quantitative et Évolution - Le Moulon
  • Université Paris-Saclay, INRAE, CNRS, AgroParisTech
  • IDEEV
  • 12 route 128
  • 91190 Gif-sur-Yvette
Judith LEGRAND

Position and education

  • Since February 2019 : Head of BASE team
  • Since 2011: Assistant professor Université Paris-Sud, Génétique Quantitative et Évolution - Le Moulon
  • 2010-2011: Post-doctoral researcher, Risk modeling and surveillance for health safety lab, Conservatoire national des Arts et Métiers and Epidemiology, Information systems, Modeling lab, INSERM-UPMC UMR-S 707, Paris - Dynamics of methicillin-resistant Staphylococcus aureus in a rehabilitation centre
  • 2007-2010: Post-doctoral position in the MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College, London - Methodological development to characterize epidemics. Applications to anthrax and influenza.
  • 2006-2007: Research engineer, Epidemiology, Information systems, Modeling lab, INSERM-UPMC UMR-S 707, Paris
  • 2006: PhD in biomathematics, Université Pierre et Marie Curie, Paris - Mathematical modeling and the preparedness against bioterrorist attacks: an application to Ebola hemorrhagic fever and smallpox.

Research interests

I use mathematical and statistical modelling to study intra and inter-specific interactions. My current research projects are related to plant biotic interactions and biological pest control.

Impact of phenology on maize-pest interactions

Plants can escape herbivores either by building up defenses such as plant secondary compounds, or by shortening their life-cycle so that they become mature before herbivore attacks. In France, Lepidoptera stem borers have a two-generations/year life-cycle. In spring, adult females lay eggs on young leaves. During summer, second generation caterpillars enter plant stems and dig galleries until ears. Completion of life-cycle occurs in non-harvested cobs during winter. Among tools for biological pest controls, sowing early maize varieties is recommended because maize stems are stronger when the second-generation larvae arise and better resist invasion. We are investigating how plant phenology shifts interfere with Lepidoptera stem borers life-cycle using theoretical and experimental approaches in the field.

→ Main collaborators : Laure Kaiser, François Rebaudo, Taiadjana Fortuna (EGCE, Paris-Saclay), Rosana Malvar, Ana Butron (MBG-CSIC, Spain), Estelle Kuhn (Maiage, INRAE), Sarah Lemlher (Ecole Centrale), Christine Dillmann, Adrienne Ressayre, Élodie Marchadier (GQE-Le Moulon), current and past students : Antoine Caillebotte, Sacha Revillon, Baptiste Régnier, Inoussa Sanane

→ Projects : Phenofore (SEMAE), Stat4Plant (ANR)

Modeling pest-parasitoid interactions for biological control

To develop sustainable agriculture, alternatives to the use of phytosanitary products for the control of crop pests are being studied within the framework of agroecological approaches, and notably biological control.

The mediterreranean corn borer (MCB), Sesamia nonagrioides (Lepidoptera: Noctuidae), is the major pest of maize in southern Europe. In France, it is present in the southern half of the country with a clear progression since the 1990s towards the north along the Atlantic coast. The first generation of MCB attacks maize in the early plant development causing loss during emergence and tillering of plants. The second generation is characterized by yield losses (reduction in the weight of seeds, lodging, loss of ears) and harvest quality (development of Fusarium in the galleries dug by the larvae). Cotesia typhae (Hymenoptera: Braconidae), is a parasitoid identified in Kenya which specifically attacks MCB. The parasitoid lays its eggs in MCB larvae which will cause their death, thus limiting the damage on maize. Our colleagues from EGCE are leading experimental studies to assess its potential as a biological control agent. In addition to experimental approaches, we are developing mathematical models of the dynamics of parasitoids and their hosts to predict the potential impact of a release of Cotesia typhae in the field.

→ Main collaborators : Laure Kaiser, François Rebaudo, Taiadjana Fortuna (EGCE, Paris-Saclay), Jean-Baptiste Thibord (Arvalis), current post-doc : Cécile Moulin

→ Projects : Phenofore (SEMAE), Stat4Plant (ANR)

Impact of phenology on maize rhizosphere microbial communities

The rhizosphere (the region of soil in the vicinity of plant roots) is an essential interface in plant-environment relationships. The microbiome associated with the plant roots compartment (also called rhizobiome) plays a role in the absorption of nutrients, the development of the host plant , its protection against colonization of the roots by pathogens and its resistance to abiotic stresses. Current climate changes are causing major phenological changes such as life cycle shifts, with earlier flowering and maturation in many perennial and annual plants. Hence, this shift could impact the rhizobiome and consequently plant-soil interactions. In maize, we are studying how maize developmental stage of the plant drives the composition of the rhizobiome using the original plant material produced in the context of the Experience de Selection Divergente du Plateau de Saclay.

→ Main collaborators : Maud Tenaillon (GQE-Le Moulon)

Teaching

Licence:

  • Statistical tests for biologists (L2)
  • Ecology and statistics (L2)
  • Modeling biological systems with ordinary differential equations (L3)
  • Introduction to programming (L2)
  • Mathematics and informatics for biology (L1 Licence Double Diplôme Mathématiques, Sciences de la Vie)
  • Biomathematics projects (L1 & L3 Licence Double Diplôme Mathématiques, Sciences de la Vie)

Master 1:

  • Biostatistics (M1 BEE)

Master 2:

  • Introduction to mathematical models of infectious diseases dynamics (M2 santé publique)
  • Introduction to statistical data analysis for optometrists (M2 Sciences de la Vision)
  • Big data (M2 GenE2)
  • Introduction to statistics (M2 Evogem)

Publications

  • Revillon S., Dillmann C., Galic N., Bauland C., Palaffre C., Malvar RA., Butron A., Rebaudo F., Legrand J. , Stout M.. (2024) Effects of maize development and phenology on the field infestation dynamics of the European corn borer (Lepidoptera: Crambidae). Journal of Economic Entomology, toae171
  • Michel E., Masson E., Bubbendorf S., Lapicque L., Nidelet T., Segond D., Guézenec S., Marlin T., Devillers H., Rué O., Onno B., Legrand J. , Sicard D.. (2023) Artisanal and farmer bread making practices differently shape fungal species community composition in French sourdoughs. Peer Community Journal, (3) e11
  • Régnier B., Legrand J. , Calatayud PA., Rebaudo F.. (2023) Developmental Differentiations of Major Maize Stemborers Due to Global Warming in Temperate and Tropical Climates. Insects, 1 (14) 51
  • Sanane I., Nicolas SD., Bauland C., Marion-Poll F., Noûs C., Legrand J. , Dillmann C.. (2023) Large genetic variability of maize leaf palatability to european corn borer : metabolic insights. bioRxiv,
  • Von Gastrow L., Michel E., Legrand J. , Amelot R., Segond D., Guezenec S., Rué O., Chable V., Goldringer I., Dousset X., Serpolay‐Bessoni E., Taupier‐Letage B., Vindras‐Fouillet C., Onno B., Valence F., Sicard D.. (2023) Microbial community dispersal from wheat grains to sourdoughs: A contribution of participatory research. Molecular Ecology, 10 (32) 2413-2427
  • Régnier B., Legrand J. , Rebaudo F., Brent C.. (2022) Modeling Temperature-Dependent Development Rate in Insects and Implications of Experimental Design. Environmental Entomology, 1 (51) 132-144
  • Sanané I., Legrand J. , Dillmann C., Marion-Poll F.. (2021) High-Throughput Feeding Bioassay for Lepidoptera Larvae. J Chem Ecol, 7 (47) 642-652
  • Harlé O., Legrand J. , Tesnière C., Pradal M., Mouret JR., Nidelet T., Ohya Y.. (2020) Investigations of the mechanisms of interactions between four non-conventional species with Saccharomyces cerevisiae in oenological conditions. PLoS ONE, 5 (15) e0233285
  • Urien C., Legrand J. , Montalent P., Casaregola S., Sicard D.. (2019) Fungal Species Diversity in French Bread Sourdoughs Made of Organic Wheat Flour. Front. Microbiol., (10) 201
  • Carbonetto B., Ramsayer J., Nidelet T., Legrand J. , Sicard D.. (2018) Bakery yeasts, a new model for studies in ecology and evolution. Yeast, 11 (35) 591-603
  • Collot D., Nidelet T., Ramsayer J., Martin OC., Meleard S., Dillmann C., Sicard D., Legrand J. . (2018) Feedback between environment and traits under selection in a seasonal environment: consequences for experimental evolution. Proceedings. Biological sciences, 1876 (285)
  • Collot D., 2018-06-19 19/06/18, Modélisation des dynamiques adaptatives de la levure de boulanger S. cerevisae dans un environnement saisonnier, PhD thesis, Université Paris-Saclay
  • Legrand J. , Bolotin-Fukuhara M., Bourgais A., Fairhead C., Sicard D.. (2016) Life-history strategies and carbon metabolism gene dosage in the Nakaseomyces yeasts. FEMS yeast research, 2 (16) fov112
  • Lhomme E., Urien C., Legrand J. , Dousset X., Onno B., Sicard D.. (2016) Sourdough microbial community dynamics: An analysis during French organic bread-making processes. Food Microbiology, Pt A (53) 41-50
  • Legrand J. , Temime L., Lawrence C., Herrmann JL., Boelle PY., Guillemot D.. (2015) Occupational Determinants of Methicillin-Resistant Staphylococcus aureus Colonization Among Healthcare Workers: A Longitudinal Study in a Rehabilitation Center. Infect. Control Hosp. Epidemiol., 7 (36) 767-776
  • Obadia T., Silhol R., Opatowski L., Temime L., Legrand J. , Thiebaut AC., Herrmann JL., Fleury E., Guillemot D., Boelle PY.. (2015) Detailed Contact Data and the Dissemination of Staphylococcus aureus in Hospitals. PLoS computational biology, 3 (11) e1004170
  • Urien C., 2015-01, Diversité des espèces de levures dans des levains naturels français produits à partir de farine issue de l'Agriculture Biologique : une étude pilote pour analyser les pratiques boulangères et les patterns des communautés microbiennes, Theses, Université Paris Sud - Paris XI
  • Spor A., Kvitek DJ., Nidelet T., Martin J., Legrand J. , Dillmann C., Bourgais A., de Vienne D., Sherlock G., Sicard D.. (2014) Phenotypic and genotypic convergences are influenced by historical contingency and environment in yeast. Evolution; international journal of organic evolution, 3 (68) 772-90