SEED DEV LAB info

The seed habit is the most complex and successful method of sexual reproduction in vascular plants. It represents a remarkable moment in the evolution of plants that afterward spread on land. In particular, seed size had a pivotal role in evolutionary success and agronomic traits, especially in the field of crop domestication. Given that crop seeds constitute one of the primary products for consumption, it follows that seed size represents a fundamental determinant of crop yield. This adaptative feature is strictly controlled by genetic traits from both maternal and zygotic tissues, although seed development and growth are also affected by environmental cues. Despite being a highly exploited topic for both basic and applied research, there are still many issues to be elucidated for developmental biology as well as for agronomic science. This review addresses a number of open questions related to cues that influence seed growth and size and how they influence seed germination. Moreover, new insights on the genetic–molecular control of this adaptive trait are presented.

The European Plant Science Retreat 2024 will take place at the south of Paris in Gif-sur-Yvette. Organised by PhD students and for PhD students, the mood will be relaxed and friendly. We will have 3 days of talks, keynotes, poster sessions and various workshops. @EPSR_2024

PhD at the INRAE IJPB-Versailles: we are looking for an enthusiastic and motivated candidate that is

willing to participate to a competition to get a scholarship at the doctoral school « Plant Sciences: from

genes to ecosystems » (SEVE) of the Paris Saclay University.

The PhD project focuses on the understanding of Arabidopsis seed metabolism and its regulation by combining genetics,

gene functional analyses and metabolomic approaches. A Master’s degree in Plant Science or related fields is required.

Thesis Director: CORSO Massimiliano, Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin.

F-box proteins have diverse functions in eukaryotic organisms, including plants, mainly targeting proteins for 26S proteasomal degradation. Here, we demonstrate the role of the F-box protein SKP1-INTERACTING PARTNER 31 (SKIP31) from Arabidopsis (Arabidopsis thaliana) in regulating late seed maturation events, seed vigor, and viability through biochemical and genetic studies using skip31 mutants and different transgenic lines. We show that SKIP31 is predominantly expressed in seeds and that SKIP31 interacts with JASMONATE ZIM DOMAIN (JAZ) proteins, key repressors in jasmonate (JA) signaling, directing their ubiquitination for proteasomal degradation independently of coronatine/jasmonic acid-isoleucine (JA-Ile), in contrast to CORONATINE INSENSITIVE 1, which sends JAZs for degradation in a coronatine/JA-Ile dependent manner. Moreover, JAZ proteins interact with the transcription factor ABSCISIC ACID-INSENSITIVE 5 (ABI5) and repress its transcriptional activity, which in turn directly or indirectly represses the expression of downstream genes involved in the accumulation of LATE EMBRYOGENESIS ABUNDANT proteins, protective metabolites, storage compounds, and abscisic acid biosynthesis. However, SKIP31 targets JAZ proteins, deregulates ABI5 activity, and positively regulates seed maturation and consequently seed vigor. Furthermore, ABI5 positively influences SKIP31 expression, while JAZ proteins repress ABI5-mediated transactivation of SKIP31 and exert feedback regulation. Taken together, our findings reveal the role of the SKIP31-JAZ-ABI5 module in seed maturation and consequently, establishment of seed vigor.

COMMUNIQUÉ DE PRESSE - INRAE et l’Université Paris-Saclay ont signé ce jeudi 9 mars 2023 une convention cadre de partenariat stratégique visant à renforcer leur collaboration dans une dynamique scientifique partagée autour de trois grands domaines : les sciences du vivant, de l’agriculture et de l’alimentation ; les mathématiques, l’ingénierie et les sciences de l’information ; les sciences humaines et sociales.

Seed dormancy is an adaptive trait which enables plants to survive adverse conditions and restart growth in a season and location suitable for vegetative and reproductive growth. Control of seed dormancy is also important for crop production and food quality because it can help induce uniform germination and prevent preharvest sprouting. Rice preharvest sprouting quantitative trait locus (QTL) analysis has identified Seed dormancy 4(Sdr4) as a positive regulator of dormancy development. Here, we analyzed the loss-of-function mutant of the Arabidopsis ortholog, Sdr4 Like1 (SFL1), and found that the sfl1-1seeds showed precocious germination at mid- to late-maturation stage similar to rice sdr4 mutant, but converted to become more dormant than the wild type during maturation drying. In sync with the dormancy levels, expression levels of the seed maturation and dormancy master regulator genes, ABI3, FUS3 and DOG1 in sfl1-1 seeds were lower than in wild type at early- and mid-maturation stages, but higher at the late-maturation stage. In addition to the seed dormancy phenotype, sfl1-1 seedlings showed a growth arrest phenotype and heterochronic expression of LAFL (LEC1, ABI3, FUS3, LEC2) and DOG1 in the seedlings. These data suggest that SFL1 is a positive regulator of initiation and termination of the seed dormancy program. We also found genetic interaction between SFL1 and the SFL2, SFL3 and SFL4 paralogs of SFL1, which impacts on the timing of the phase transition from embryo maturation to seedling growth.

Depuis la Seconde Guerre mondiale, l’agronomie est devenue une discipline scientifique et technique à part entière, qui appuie le raisonnement des pratiques de production végétale. Conçue initialement comme application de la chimie agricole et de la physiologie végétale, elle a développé ses propres concepts et étendu son domaine, en intégrant les savoirs issus de nombreuses autres disciplines. Elle s’est aussi construite en étudiant les pratiques des agriculteurs et des autres acteurs de l’espace rural. Ces évolutions lui ont permis de renouveler son utilité, en répondant aux nouveaux enjeux auxquels l’agriculture n’a cessé d’être confrontée.
Comment s’est opérée cette construction ? Quels en ont été les processus, les étapes et les acteurs ? En analysant la manière dont l’agronomie s’est façonnée en France, du milieu du xxe siècle à nos jours, La Fabrique de l’agronomie vise à éclairer l’avenir et à susciter des réflexions utiles sur les conditions de son développement dans les prochaines décennies.
Cet ouvrage sur l’évolution de la discipline s’adresse notamment aux agronomes de tous métiers confrontés aux défis à venir, qu’ils soient étudiants, actifs ou retraités.

Embryo development in Arabidopsis (Arabidopsis thaliana) starts off with an asymmetric division of the zygote to generate the precursors of the embryo proper and the supporting extraembryonic suspensor. The suspensor degenerates as the development of the embryo proper proceeds beyond the heart stage. Until the globular stage, the suspensor maintains embryonic potential and can form embryos in the absence of the developing embryo proper. We report a mutant called meerling-1 (mrl-1), which shows a high penetrance of suspensor-derived polyembryony due to delayed development of the embryo proper. Eventually, embryos from both apical and suspensor lineages successfully develop into normal plants and complete their life cycle. We identified the causal mutation as a genomic rearrangement altering the promoter of the Arabidopsis U3 SMALL NUCLEOLAR RNA-ASSOCIATED PROTEIN 18 (UTP18) homolog that encodes a nucleolar-localized WD40-repeat protein involved in processing 18S preribosomal RNA. Accordingly, root-specific knockout of UTP18 caused growth arrest and accumulation of unprocessed 18S pre-rRNA. We generated the mrl-2 loss-of-function mutant and observed asynchronous megagametophyte development causing embryo sac abortion. Together, our results indicate that promoter rearrangement decreased UTP18 protein abundance during early stage embryo proper development, triggering suspensor-derived embryogenesis. Our data support the existence of noncell autonomous signaling from the embryo proper to prevent direct reprogramming of the suspensor toward embryonic fate.

Publiée mercredi 3 juillet 2024, l’enquête « le vivant et le politique » est l’aboutissement du programme collaboratif de recherche ComingGen, financé par l’agence nationale de la recherche (ANR), sous la direction scientifique de Virginie Tournay, chercheuse au CEVIPOF.

Il vise à analyser les liens complexes entre les opinions publiques et la décision politique sur des sujets relatifs au monde vivant et aux biotechnologies.

Porté par le CEVIPOF, le projet est conduit en partenariat avec des chercheurs du laboratoires PACTE (Séverine Louvel), le LESSEM de l’INRAE (Céline Granjou) et le laboratoire d’épidémiologie et de santé publique de l’INSERM (Emmanuelle Rial-Sebbag).

En partenariat avec les laboratoires PACTE et LESSEM, l’enquête réalisée en ligne a pour objectif de mieux comprendre les relations entre les représentations du monde vivant, la nature et la manière de penser l’ordre social et politique.

Elle a été conduite dans trois pays dont la particularité est d’avoir un rapport contrasté vis-à-vis de l’Europe : La France, le Royaume-Uni et la Pologne. Le terrain a été réalisé en mai 2024 par l’institut BVA Xsight.

TÉLÉCHARGER L'ÉTUDE (PDF, 2,2 MO) 

28/09/2023 à 9h30 Animateur(s) : Serge POULET, Agnès RICROCH, Jean-Claude PERNOLLET, Chris BOWLER, Francis MARTIN Philippe,  KIM-BONBLED et Dominique JOB, IMPORTANT : pour vous inscrire : https://my.weezevent.com/ADNe 

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emissions and loss of biodiversity1. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value2. Faba bean (Vicia faba L.) has a high yield potential and is well suited for cultivation in temperate regions, but genomic resources are scarce. Here, we report a high-quality chromosome-scale assembly of the faba bean genome and show that it has expanded to a massive 13 Gb in size through an imbalance between the rates of amplification and elimination of retrotransposons and satellite repeats. Genes and recombination events are evenly dispersed across chromosomes and the gene space is remarkably compact considering the genome size, although with substantial copy number variation driven by tandem duplication. Demonstrating practical application of the genome sequence, we develop a targeted genotyping assay and use high-resolution genome-wide association analysis to dissect the genetic basis of seed size and hilum colour. The resources presented constitute a genomics-based breeding platform for faba bean, enabling breeders and geneticists to accelerate the improvement of sustainable protein production across the Mediterranean, subtropical and northern temperate agroecological zones. Using a high-quality chromosome-scale assembly of the faba bean genome, the genetic basis of seed size and hilum colour is explored.

Multicellular organisms undergo several developmental transitions during their life cycles. In contrast to animals, the plant germline is derived from adult somatic cells. As such, the juvenility of a plant must be reset in each generation. Previous studies have demonstrated that the decline in the levels of miR156/7 with age drives plant maturation. Here we show that the resetting of plant juvenility during each generation is mediated by de novo activation of MIR156/7 in Arabidopsis. Blocking this process leads to a shortened juvenile phase and premature flowering in the offspring. In particular, an Arabidopsis plant devoid of miR156/7 flowers even without formation of rosette leaves in long days. Mechanistically, we find that different MIR156/7 genes are reset at different developmental stages through distinct reprogramming routes. Among these genes, MIR156A, B and C are activated de novo during sexual reproduction and embryogenesis, while MIR157A and C are reset upon seed germination. This redundancy generates a robust reset mechanism that ensures accurate restoration of the juvenile phase in each plant generation. In Arabidopsis, microRNAs control the transition from juvenile to adult states. The study, using genomic, genetic and molecular approaches, investigates how miR156 and miR157 are re-activated at each generation.

La préservation de la biodiversité est l'une des missions que s'est fixée l'Université dans sa Charte Développement Soutenable, en participant à la remédiation écologique des territoires, en priorisant la préservation des milieux naturels et cultivés, la restauration des fonctions écosystémiques et la libre évolution de la biodiversité.

L'Université Paris-Saclay organise pour la première fois des journées consacrées à la biodiversité. Au programme, afin de sensibiliser et de faire découvrir la faune et la flore de nos campus, des visites, des projections et des expositions sont organisées.

https://www.universite-paris-saclay.fr/actualites/journees-de-la-biodiversite-du-21-au-24-mai-la-biodiversite-sur-nos-campus

Au programme :

Concours photos :

1) Photographiez la biodiversité de nos campus

2) Postez vos photos sur Instagram en identifiant le compte @ds_upsaclay et en utilisant le #BiodiversiteSurNosCampus

3) Envoyez-nous en DM votre nom, prénom et votre fonction/année de formation

Les 20 premièr·es participant·es gagneront un lot qui sera remis le mardi 24 mai à l’occasion de l’exposition organisée à l’IDEEV.

Participations jusqu’au 23 mai à 12h. Les participant.es s’engagent à respecter le règlement à être présent·es à la remise des prix le 24 mai à 14h (si elles ou ils sont sélectionné·es) ou à renoncer à leur lot.