Bruno Guillotin has joined the IPS2 unit (Institute of Plant Sciences Paris-Saclay) as a CNRS Research Scientist. He was recruited in February 2025.   After studying Plant Biology and Physiology, he completed his PhD between 2013 and 2016 at the Plant Science Research Laboratory (LRSV – Toulouse) under the supervision of Guillaume Bécard and Jean-Philippe Combier. His doctoral work focused on the autoregulation of arbuscular mycorrhizal symbiosis in Medicago truncatula.   Following his PhD, he turned his attention to the study of root development in various plant species as a postdoctoral researcher in Kenneth Birnbaum’s group at New York University. There, supported by a Human Frontiers Long-Term Fellowship, he developed numerous protocols for single-cell transcriptomics (single-cell RNA-seq), which he implemented to study gene evolution across agronomically relevant species (maize, sorghum, millet), as well as to investigate cell regeneration in the roots of Arabidopsis thaliana.   In 2025, he was appointed as a CNRS Research Scientist and was also awarded the CNRS–INSERM ATIP-Avenir grant. At IPS2, Bruno Guillotin’s research focuses on understanding how plant cells communicate through plasmodesmata, aiming to identify which proteins and peptides move from one cell to another and contribute to organ morphogenesis in plants. His work combines single-cell RNA-seq, proteomics, genomics, and bioinformatics approaches.   Contact email : [email protected]

The HeatDDR Doctoral Network was officially launched on March 1, 2025, merging 17 European partners to train 9 PhD students in Plant Sciences. Funded by Horizon Europe through the Marie Skłodowska-Curie Actions (€2.2 million), this four-year project is coordinated by the Paris-Saclay University, with Dr. Cécile Raynaud (Research Director at the Institute of Plant Sciences Paris-Saclay, IPS2) as scientific coordinator.   The initiative addresses one of the biggest challenges in modern agriculture: sustaining crop productivity and food security to face climate change. Northern Europe is expected to see longer, warmer, and more humid summers, while southern Europe faces increasing heat and drought stress. HeatDDR focuses on understanding how heat stress affects plant development, particularly through the DNA Damage Response (DDR), a mechanism that plays a dual role, contributing to thermotolerance while limiting plant growth. By studying DDR, the project aims to maintain crop yields without compromising stress resilience. The network provides an interdisciplinary training program, combining academic research together with practical training in both universities and industry. Each PhD student will benefit from supervision by multiple partners, advanced technical training, and the development of soft skills essential for a scientific career. The HeatDDR project kick-off meeting will take place on December 2–3, 2025, in Giessen, Germany, bringing together the newly recruited PhDs and other members of the consortium to officially launch the collaborative research and training initiatives. Over the next four years, the network will hold additional workshops and a final three-day symposium hosted by the Paris-Saclay University in 2029, where students will present their research alongside invited experts.   Contacts : Cécile Raynaud, Coordinator – Université Paris-Saclay / IPS2 / SPS - [email protected] Alberto Ballin, Project Manager – Université Paris-Saclay / IPS2 SPS [email protected]

Cette nomination intervient après 11 années de service d’Alexandre Péry, qui a exercé successivement les fonctions de directeur puis de directeur adjoint de l’école doctorale. Le professeur Rajjou reprend le périmètre des unités dont Alexandre était correspondant, notamment le suivi pédagogique et scientifiques des doctorantes et doctorants, ainsi que la coordination opérationnelle de l’école doctorale. Dans le cadre de ses nouvelles fonctions, il contribuera activement au développement de l’offre de formation doctorale et participera pleinement au fonctionnement de la direction de l’école doctorales ABIES.    Professeur de biologie végétale à AgroParisTech, le professeur Rajjou conduit ses activités de recherche au sein de l’Institut Jean-Pierre Bourgin - Sciences du Végétal - IJPB (INRAE/AgroParisTech/UPSaclay, Versailles). Ses travaux scientifiques portent principalement sur les mécanismes moléculaires et cellulaires qui déterminent la qualité des semences. Il développe également des solutions innovantes de biocontrôle et de biostimulant destinées à promouvoir une agriculture durable et résiliente face aux défis climatiques et environnementaux. Il coordonne et participe à de nombreux projets de recherche d’envergure nationale et européenne, démontrant sa capacité à fédérer des équipes scientifiques autour d’objectifs communs. Il a co-fondé SEED IN TECH, une start-up issue de ses travaux de recherche sur l’optimisation des semences.   Il possède une expérience approfondie du monde doctoral. Il a dirigé et co-encadré de nombreuses thèses, développant ainsi une connaissance fine des enjeux liés à l’accompagnement des jeunes chercheurs.    Cette nomination renforce l’engagement de l’école doctorale ABIES dans l’accompagnement d’excellence de ses doctorantes et doctorants ainsi que dans le développement d’une formation doctorale innovante et adaptée aux défis scientifiques et sociétaux contemporains.   -> Contact : [email protected]

Surprisingly, differences in phenotypes and gene expression are observed between genetically identical individuals grown in the same environment. While we now have a good knowledge of the source and consequences of transcriptional differences observed between cells, in particular for unicellular organisms, it is still very scarce when it comes to variability between multicellular organisms. Using plants as a model we analysed the establishment, maintenance and consequences of inter-individual transcriptional variability. We showed, for a gene of interest, that differences in expression between plants are established in young seedlings and maintained over several days. Our results also indicate that these differences in expression can explain phenotypic variability between plants such as for the root growth. Finally, using a genome-wide approach, we found a co-expression in seedlings for our gene of interest, involved in nitrate nutrition, and genes involved in photosynthesis. All in all, our study suggests that a global coordination of the genes involved in the carbon/nitrate balance in plants is established in young seedlings, with differences between plants, and then maintained over time.

COMMUNIQUE DE PRESSE - Sophie Nicklaus est officiellement nommée directrice scientifique Alimentation et Santé pour 4 ans, par Philippe Mauguin, président-directeur général d’INRAE, après consultation de son conseil d’administration ce 13 octobre. Désormais membre du collège de direction de l’institut, Sophie Nicklaus était depuis avril 2024 directrice scientifique adjointe Alimentation et Bioéconomie auprès de Monique Axelos qui fera valoir ses droits à la retraite à la fin de l’année. Face aux enjeux de sécurité et souveraineté alimentaire, de durabilité et de coût de l’alimentation et aux défis de santé publique et d’innovation, INRAE a choisi de cibler les missions de la nouvelle directrice scientifique sur les domaines de l’alimentation et de la santé, afin de contribuer à l’alimentation de demain, une alimentation saine, durable et accessible à tous. Une direction scientifique dédiée à la bioéconomie, préfigurée par Monique Axelos, sera mise en place à la fin de l’année.

Deeper collaboration between EMBL-EBI and Google DeepMind brings updates to the AlphaFold Database.

International Master in Plant Sciences track of the Biology AgroSciences master degree https://www.master-sciences-du-vegetal.fr/eng We are delighted to share that the International Master in Plant Sciences track of the Biology AgroSciences Master degree will soon be launching (September 2026). Fully taught in English (First and second year) and embedded in the Saclay Plant Sciences Excellence Network, this program will train a new generation of talented students to tackle the most pressing challenges in plant research — from climate resilience to sustainable agriculture.

"Flavonoid metabolites dye many plant organs such as flowers, fruits, seeds, leaves or tubers. Over the past 150 years, tracking flavonoid-related colour changes in plants has shaped the foundation of many modern biology questions. This includes ground-breaking discoveries such as Gregor Mendel’s law of inheritance (using white and purple pea flowers), Barbara McClintock’s identification of transposable elements (through her research on variably coloured maize kernels) or Carolyn Napoli’s description of co-suppression (based on her observations of altered and novel flower colouration in petunia). In recent decades, the intricate, diverse and finely tuned flavonoid pathway has been unravelled and the understanding of this pathway across various plant species owes much to the characterization of mutants disrupted in the biosynthesis, transport and storage of flavonoids that similarly displayed modified flower and seed pigmentation (Winkel-Shirley 2001; Koes et al. 2005; Lepiniec et al. 2006). The model plant A. thaliana provided a wealth of such mutants (transparent testa mutants, tt) exhibiting altered seedcoat colours (Fig. 1) (Koornneef 1990; Shirley et al. 1992; Lepiniec et al. 2006). Their characterization enabled researchers to associate genes or loci with flavonoid-related functions. However, although their visual and non-lethal phenotypes were easy to identify and offered insight into the disrupted gene functions, further investigation was required to confirm these functions. Beyond colour, to fully unravel this pathway, it has become essential to individually characterize the seed flavonoids, determine their spatial and temporal distribution, and their diversity. This laid the groundwork for validating locus functions, characterizing novel gene roles, and identifying as well as quantifying flavonoid accumulation in other plants".

Chemical interactions between plants and their environment: from the molecule to the field 23-25 September 2026 - IJPB, INRAE Ile-de-France - Versailles-Saclay The IJPB is organising the 3rd edition of its international symposium. Following the editions in 2018 and 2024, this event will take place in Versailles from 23 to 25 September 2026. Save the date! The IJPB Symposium 2026 is dedicated to "Chemical interactions between plants and their environment: from the molecule to the field", a booming research field in which IJPB develops integrative approaches bridging plant metabolism and its effect on biotic/abiotic interactions and vice versa. The symposium will comprise an opening lecture and four thematic sessions, each involving an international and an IJPB keynote speaker, as well as presentations from participants selected from submitted abstracts. The themes of each session are as follows: 1 - Identification/analysis of chemical signals involved in plant response to their environment  2 - Molecular and cellular mechanisms of chemical responses to biotic and abiotic stress: Perception and transduction of chemical signals 3 - Integration of chemical interactions in ecological communities and agroecosystems  4 - Agroecological innovations derived from the study of how plants interact with their environment This exciting meeting aims to foster collaborations and facilitate knowledge exchange among participants by bringing together renowned specialists in the field and a high level of interdisciplinary. The symposium will also feature a workshop on plant specialized metabolite analysis, conducted in collaboration with the Chemistry/Metabolism platform PO-Chem, and a tour of the Plant Facilities PO-Plants and the Phenoscope PO-Pheno, all three of which are part of the Plant Observatory (PO) of the IJPB. Ahead of the symposium, the ENVIE Network will hold its 5th plenary edition in Versailles from 21 to 23 September 2026, organised as part of a MULTISTRESS satellite workshop. We look forward to meeting you in Versailles! Further information will be available by November 2025. In connection with the research developed at the Institute Jean-Pierre Bourgin for Plant Sciences.

Chemical interactions between plants and their environment: from the molecule to the field 23-25 September 2026 - IJPB, INRAE Ile-de-France - Versailles-Saclay The IJPB is organising the 3rd edition of its international symposium. Following the editions in 2018 and 2024, this event will take place in Versailles from 23 to 25 September 2026. Save the date! The IJPB Symposium 2026 is dedicated to "Chemical interactions between plants and their environment: from the molecule to the field", a booming research field in which IJPB develops integrative approaches bridging plant metabolism and its effect on biotic/abiotic interactions and vice versa. The symposium will comprise an opening lecture and four thematic sessions, each involving an international and an IJPB keynote speaker, as well as presentations from participants selected from submitted abstracts. The themes of each session are as follows: 1 - Identification/analysis of chemical signals involved in plant response to their environment  2 - Molecular and cellular mechanisms of chemical responses to biotic and abiotic stress: Perception and transduction of chemical signals 3 - Integration of chemical interactions in ecological communities and agroecosystems  4 - Agroecological innovations derived from the study of how plants interact with their environment This exciting meeting aims to foster collaborations and facilitate knowledge exchange among participants by bringing together renowned specialists in the field and a high level of interdisciplinary. The symposium will also feature a workshop on plant specialized metabolite analysis, conducted in collaboration with the Chemistry/Metabolism platform PO-Chem, and a tour of the Plant Facilities PO-Plants and the Phenoscope PO-Pheno, all three of which are part of the Plant Observatory (PO) of the IJPB. Ahead of the symposium, the ENVIE Network will hold its 5th plenary edition in Versailles from 21 to 23 September 2026, organised as part of a MULTISTRESS satellite workshop. We look forward to meeting you in Versailles! Further information will be available by November 2025. In connection with the research developed at the Institute Jean-Pierre Bourgin for Plant Sciences.

"Interspecific hybridization may trigger species radiation by creating allele combinations and traits. Cultivated potato and its 107 wild relatives from the Petota lineage all share the distinctive trait of underground tubers, but the underlying mechanisms for tuberization and its relationship to extensive species diversification remain unclear. Through analyses of 128 genomes, including 88 haplotype-resolved genomes, we revealed that Petota is of ancient hybrid origin, with all members exhibiting stable mixed genomic ancestry, derived from the Etuberosum and Tomato lineages ca. 8-9 million years ago. Our functional experiments further validated the crucial roles of parental genes in tuberization, indicating that interspecific hybridization is a key driver of this innovative trait. This trait, along with the sorting and recombination of hybridization-derived polymorphisms, likely triggered the explosive species diversification of Petota by enabling occupation of broader ecological niches. These findings highlight how ancient hybridization fosters key innovation and drives subsequent species radiation."

  "ABA response is tightly modulated by nitrogen nutrition   NRT1.1B acts as a dual receptor to competitively bind ABA and nitrate   NRT1.1B-SPX4-NLP4 cascade underlies ABA signaling from the plasma membrane to the nucleus   NRT1.1B integrates compound environmental cues across different species in plants"

• LEC2 reprograms somatic epidermal cells into totipotent somatic embryo founder cells • LEC2 and SPCH co-activate local auxin biosynthesis by targeting TAA1 and YUC4 • GMC-auxin state marks stomatal cells shifting from differentiation to totipotency • Transcriptional rewiring and auxin signaling drive reprogramming of stomatal cells

Compte officiel de l'Université Paris-Saclay : 48 000 étudiants, 9 000 chercheurs et enseignants-chercheurs, 4 600 doctorants #Formation #Recherche