Membre du comité d'organisation logistique et scientifique

A holistic overview of the impact of sulfur deficiency in pea facing water deficit

We report on the interplay between water deficit and sulfur deficiency, two constraints that are increasingly faced by crops due to climate change and low-input agricultural practices. In particular, we aim at better understanding the role of sulfur nutrition in the trade-off between seed quality establishment and plant stress tolerance in pea (Pisum sativum L.), a grain legume crop which has a pivotal role to play in both agroecological and food transitions. Like other legumes, pea is able to accumulate large amounts of seed proteins even in the absence of nitrogen fertilizers thanks to its symbiosis with N2-fixing soil bacteria. In this study, we deprived pea plants (cv. Caméor) of sulfur…

Over-expression of the epidermis-specific HD-ZIP IV transcription factor OCL1 in maize identifies target genes involved in lipid metabolism and cuticle biosynthesis.

International audience

Use of translational genomics to identify genes important for legume seed filling

International audience; Translational genomics, i.e., the transfer of genetic information from model species to cultivated crops, is on the brink of revolutionizing plant breeding. The recent publication of genomic sequences for several cultivated legumes is also accelerating this process. For pea, recent highthroughput RNA sequencing, and the prospect of a genome sequencing project, will further accelerate the transfer of information from the Medicago truncatula model to the cultivated crop. We have been using genomics approaches with Medicago as a tool to identify key genes determining seed yield and composition in closely related legumes. Analyses of the proteome and transcriptome of the…

Storage cells – oil and protein bodies

BAPGEAPSI; Molecular Cell Biology of the Growth and Differentiation of Plant Cells encompasses cell division, cell enlargement and differentiation; which is the cellular basis of plant growth and development. Understanding these developmental processes is fundamental for improving plant growth and the production of special plant products, as well as contributing to biological understanding. The dynamics of cells and cellular organelles are considered in the context of growth and differentiation, made possible particularly by advances in molecular genetics and the visualization of organelles using molecular probes. There is now a much clearer understanding of these basic plant processes of c…

Propriétés organoleptiques des graines de pois : la génétique peut-elle améliorer le goût ?

L'utilisation de légumineuses comme source de protéines dans les produits alimentaires transformés est souvent limitée par le goût « vert » désagréable qu'elles peuvent conférer. Parmi les composés source de mauvais goût figurent les saponines, des triterpènes glycosylés qui contribuent à l'amertume, et les composés organiques volatiles (COV), notamment l’héxanal, qui proviennent de l’oxydation des acides gras insaturés présents dans les graines par des lipoxygénases, et qui donnent un goût « vert, herbeux » au produit fini. Les méthoxypyrazines se trouvent également en petites quantités dans les graines et pourraient être aussi impliquées dans la détermination de la note verte, bien que le…

Effet de la variété sur les teneurs en métabolites secondaires dans les farines de pois

National audience

Comment la plante récupère-t-elle après un stress hydrique ? Une étude écophysiologique et moléculaire chez la légumineuse à graines Pisum sativum

EABAPGEAPSI DOCT INRA; Le pois (Pisum sativum) possède la capacité de fixer l’azote atmosphérique via une symbiose avec des bactéries du sol, permettant ainsi de s’affranchir d’engrais azotés. Cependant, ce processus est très sensible au stress hydrique, et reste affecté même lorsque les conditions hydriques redeviennent optimales. Or, la capacité d’une plante à récupérer après un stress hydrique peut être déterminante pour l’élaboration de son rendement. Pourtant, les mécanismes enclenchés lors de la phase de récupération restent peu connus. Le but de cette thèse est d’évaluer la capacité de la plante à récupérer après un stress hydrique et d’identifier les processus écophysiologiques et m…

Characterization of the biosynthesis of saponins during seed development in peas (Pisum sativum)

National audience; The use of pulses as ingredients for the production of food products rich in plant proteins is increasing. However, protein fractions prepared from pea or other pulses contain significant amounts of saponins, glycosylated triterpenes which can impart a bitter taste to the final food product. Bitter flavours are currently either removed by energy-requiring physico-chemical treatments or masked by additives. We are in the process of identifying and characterizing the genes involved in saponin biosynthesis during pea seed development, with the objective of identifying mutants in which seed saponins no longer accumulate. To do this we have applied a saponin extraction protoco…

Grain legumes for human consumption: management of off-flavours

International audience

How does pea (Pisum sativum) recover from water deficit?

International audience

Document de synthèse du groupe de travail "enjeux et questions de recherche sur protéines végétales communes entre les départements TRANSFORM & BAP"

National audience

Des potentiels régulateurs des réponses au stress hydrique et à la carence en soufre identifiés grâce à une analyse multi-omiques chez le pois

Dans leur environnement naturel, les plantes doivent faire face à plusieurs stress biotiqueset abiotiques au cours de leur cycle de développement. Certains de ces stress peuventsurvenir au même moment – comme le stress hydrique et les carences nutritionnelles – etpeuvent avoir des effets synergiques, antagonistes ou additifs sur les réponses moléculairesdes plantes. Chez le pois (Pisum sativum), il a été observé que l’effet de la carence en soufre(S) sur la composition protéique des graines peut être atténué lorsque cette carence estcombinée à un stress hydrique (Henriet et al., 2019). Afin de mieux caractériser les réponsesmoléculaires du pois au stress hydrique et/ou à la carence en S, un…

Optimizing response to abiotic stress

International audience

Dissection of pea responses to water stress during seed filling identifies candidate genes for drought tolerance

International audience; Given their ability to fix atmospheric nitrogen, legumes are pivotal to the development of sustainable agriculture in Europe as a source of protein for food and feed. Pea (Pisum sativum) is currently the leading grain legume crop in France and major efforts are being made to reintroduce legumes as protein crops in Europe. However, instability of seed yield and quality due to environmental fluctuations still represent a real barrier for the development of these cultures, and breeding for stable yields is needed. In pea, drought stress occurring during the reproductive phase can greatly affect seed yield and quality. We investigated the response of pea plants (var. Cam…

Time-series RNA-seq analysis of pea seeds during development under control and drought conditions

National audience; Pea (Pisum sativum) produces seeds rich in proteins. However, protein content and seed quality can be impacted by environmental factors including drought. Accumulation of seed storage proteins (SSP) during seed filling is a highly regulated process. While proteomics of SSP deposition in pea seeds is well documented, knowledge of the underlying regulatory gene networks, either in control or stress conditions, is lacking. In this study, a RNA-seq based transcriptome analysis of seed development in control and water stress condition was carried out. Developing seeds were collected at six time points, from late embryogenesis to early maturation. RNA-seq was performed on an Il…

Role of vacuolar sulfate in nutritional quality of pea seeds

Grain legumes have a key role to play in both agroecological and food transitions. Indeed, these plants are able to accumulate large amounts of proteins in their seeds even in the absence of nitrogen fertilization thanks to symbiotic N2 fixation in the root nodules. However, legumes are exposed to abiotic stresses, including nutrient deficiencies, making it important to optimize nutrient use efficiency for maintaining seed protein content and quality. Seed protein quality refers to the ability of the seed proteins to meet the body’s requirements for essential amino acids. It strongly depends on the amino acid balance, which determines protein digestibility. In pea (Pisum sativum) seeds, met…

Use of translational genomics to identify genes important for legume seed development

BAP Pôle GEAPSI; International audience; We have exploited the extensive synteny between the model legume Medicago truncatula and the cultivated garden pea, Pisumsativum, to identify loci controlling seed filling and seedcomposition in the crop species. QTLs for these traits are mapped by analyzing variation with in collections of recombinant inbred lines. Candidate genes with in the QTL intervals are identified by reference to the M.truncatula genomic sequence. This approach was used to uncover an endosperm subtilase that is associated with syntenic seed weight QTLs in Medicago and pea, and we discuss the possible role played by this enzyme in contributing to final seed weight.

The role of sulfur nutrition in the pea response to drought

International audience

Analyse écophysiologique de la récupération après un stress hydrique chez la légumineuse à graines Pisum sativum

National audience; Le pois (Pisum sativum) possède la capacité de fixer l’azote atmosphérique via une symbiose avec des bactéries du sol, au sein de structures racinaires appelées nodosités, permettant ainsi de s’affranchir de l’apport d’engrais azotés pour sa culture. Cependant, la fixation symbiotique de l’azote est un processus très sensible au stress hydrique qui l’affecte négativement. Bien que la capacité d’une plante à récupérer après un stress hydrique puisse être déterminante pour sa survie et l’élaboration de son rendement, les mécanismes enclenchés lors de cette phase restent peu connus. Afin d’évaluer la capacité du pois à récupérer après un stress hydrique, notamment en termes …

The role of sulfur in the control of seed quality traits in legumes: from model to crop species

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Multi-omics network analysis identifies putative regulators of molecular responses to water stress and sulfur deficiency in Pisum sativum

Plants in their physical environment face multiple biotic and abiotic stresses duringtheir life cycle. In nature, environmental stresses often co-occur – such as water deficit andnutrient deficiencies – and can have synergistic, antagonistic or additive effects on the plantmolecular responses. In pea (Pisum sativum), combination of water stress (WS) and sulfur (S)deficiency showed a mitigation effect on the seed protein composition, as compared to Sdeficiency occurring alone (Henriet et al., 2019). To better understand how pea responds toWS and/or S deficiency, a multi-omics (transcriptomics, proteomics, metabolomics, ionomics)analysis has been performed from leaf samples collected during a…

Étude de la résilience du pois et de la Féverole au stress hydrique

Regulation of legume seed size by an endosperm-expressed transcription factor

BAP Pôle GEAPSI; International audience; There are numerous reports of transcription factors (TFs) which are implicated in the control of seed size and seed composition. We have identified, using a platform of TF sequences derived from the Medicago truncatula genome sequence, a class of TFs specifically expressed during the seed filling stage. One such TF, DASH, was shown to be confined to the developing endosperm. We investigated the role played by DASH through analysis of mutant alleles. These give rise to seed-lethal or near-lethal phenotypes, with degeneration of the endosperm and arrested embryo development. The relation of this phenotype to seed auxin action was investigated.

β-Amyrin Synthase1 Controls the Accumulation of the Major Saponins Present in Pea (Pisum sativum)

Abstract The use of pulses as ingredients for the production of food products rich in plant proteins is increasing. However, protein fractions prepared from pea or other pulses contain significant amounts of saponins, glycosylated triterpenes that can impart an undesirable bitter taste when used as an ingredient in foodstuffs. In this article, we describe the identification and characterization of a gene involved in saponin biosynthesis during pea seed development, by screening mutants obtained from two Pisum sativum TILLING (Targeting Induced Local Lesions IN Genomes) populations in two different genetic backgrounds. The mutations studied are located in a gene designated PsBAS1 (β-amyrin s…

Drought Stress Memory at the Plant Cycle Level: A Review

International audience; Plants are sessile organisms whose survival depends on their strategy to cope with dynamic, stressful conditions. It is urgent to improve the ability of crops to adapt to recurrent stresses in order to alleviate the negative impacts on their productivity. Although our knowledge of plant adaptation to drought has been extensively enhanced during the last decades, recent studies have tackled plant responses to recurrent stresses. The present review synthesizes the major findings from studies addressing plant responses to multiple drought events, and demonstrates the ability of plants to memorize drought stress. Stress memory is described as a priming effect allowing a …

Pea Efficiency of Post-drought Recovery Relies on the Strategy to Fine-Tune Nitrogen Nutrition

International audience; As drought is increasingly frequent in the context of climate change it is a major constraint for crop growth and yield. The ability of plants to maintain their yield in response to drought depends not only on their ability to tolerate drought, but also on their capacity to subsequently recover. Post-stress recovery can indeed be decisive for drought resilience and yield stability. Pea (Pisum sativum), as a legume, has the capacity to fix atmospheric nitrogen through its symbiotic interaction with soil bacteria within root nodules. Biological nitrogen fixation is highly sensitive to drought which can impact plant nitrogen nutrition and growth. Our study aimed at dyna…

Etude du rôle de la nutrition soufrée dans la réponse du pois au stress hydrique: vers la construction de réseaux protéiques

International audience

L'amélioration de la qualité de la graine dans toutes ses dimensions, par le levier génétique

Les légumineuses sont capables d’accumuler des quantités importantes de protéines dans leurs graines même en l’absence d’engrais azoté, ce qui fait d’elles des espèces à haut potentiel pour relever les défis alimentaires et accompagner la transition agroécologique. Des avancées génétiques ont permis de réduire la présence de certains facteurs « anti-nutritionnels » dans les graines de pois et de féverole (exemple des variétés pauvres en tanins, en inhibiteurs trypsiques, ou en vicine et convicine). Afin de promouvoir l’utilisation de ces graines en alimentation humaine, il est nécessaire d’aller plus loin dans l’amélioration de leur valeur nutritionnelle, en termes de teneur et composition …

Sulfate transporters in the plant’s response to drought and salinity: regulation and possible functions

International audience; Drought and salinity are two frequently combined abiotic stresses that affect plant growth, development, and crop productivity. Sulfate, and molecules derived from this anion such as glutathione, play important roles in the intrinsic responses of plants to such abiotic stresses. Therefore, understanding how plants facing environmental constraints re-equilibrate the flux of sulfate between and within different tissues might uncover perspectives for improving tolerance against abiotic stresses. In this review, we took advantage of genomics and post-genomics resources available in Arabidopsis thaliana and in the model legume species Medicago truncatula to highlight and …

How does pea (Pisum sativum) recover from water deficit?

International audience; Pea (Pisum sativum), like other legumes, has the unique ability to fix atmospheric dinitrogen (N2) via symbiosis with soil bacteria known as rhizobia in root nodules. This particular feature makes the pea crop an essential component of sustainable cropping systems because of the reduction of nitrogen fertilizers it affords. However symbiotic nitrogen fixation (SNF) is very susceptible to abiotic stresses and particularly to water deficit, which is becoming an increasingly common threat in the current context of climate change. Water deficit impacts negatively SNF (Prudent et al., 2016), affecting both nodule number and growth (i.e. structural components of SNF) and t…

Recherche des gènes contrôlant la plasticité de la composition protéique des graines vis-à-vis de l’environnement par une approche GWAS chez Medicago truncatula

National audience; Les légumineuses sont capables de produire des graines riches en protéines en l’absence d’apports azotés grâce aux symbioses qu’elles établissent avec des bactéries fixatrices d’azote de l’air. Riches en lysine, ces protéines sont utilisées pour la nutrition humaine et l’alimentation animale. Cependant, les instabilités de la teneur et de la composition protéique des graines causées par les variations environnementales limitent l’adoption des légumineuses en Europe. Afin de promouvoir leur culture, il est nécessaire d’optimiser et de stabiliser la quantité et la qualité de cette fraction protéique. Nous avons étudié la plasticité de la teneur et de la composition protéiqu…

Importance du sulfate vacuolaire pour l’établissement du rendement et de la qualité des graines de pois

Les graines de pois constituent un aliment sain et nourrissant, notamment de par leur forte teneur en protéines (environ 25%). La qualité nutritionnelle de ces protéines est néanmoins limitée par leur faible proportion en acides aminés soufrés (AAS) : cystéine et méthionine. L’objectif était d’étudier la contribution du stock de sulfate contenu dans les vacuoles à l’élaboration du rendement et de la qualité des graines, notamment la synthèse des AAS. Nous avons ciblé l’unique gène SULTR4 de pois qui code un transporteur permettant l’efflux de sulfate de la vacuole vers le cytosol. Après avoir confirmé sa localisation à la membrane vacuolaire, nous avons recherché des mutants de pois pour ce…

Studying the interplay between sulfur nutrition and water stress tolerance in pea by proteomics : a focus on seed development and composition

International audience; Water stress and sulfur-deficiency are two constraints increasingly faced by crops due to climatechange and low-input practices. To investigate their interplay in the grain legume pea (Pisum sativumL.), sulfate was depleted at mid-vegetative stage and a moderate 9-day water stress period was imposedduring the early reproductive phase. The combined stress accelerated seed production, lowering yield,one-seed weight and seed number per plant, but rebalanced seed protein composition. In fact, themoderate water stress mitigated the negative effect of sulfur-deficiency on the accumulation of sulfurrichproteins in seeds, probably due to a lower seed sink strength for nitrog…

The pea sulfate transporter, PsSULTR4, contributes to seed yield and quality

To investigate the role of vacuolar sulfate in seed yield and quality, we have targeted the single pea SULTR4 gene (PsSULTR4), which encodes a transporter homologous to Arabidopsis SULTR4;1 and 4;2 that allow sulfate efflux from the vacuole to the cytosol. By simulating the 3D structure of PsSULTR4, we observed that it is similar to that of SULTR4;1 in Arabidopsis. Furthermore, a phylogenetic analysis revealed a high level of conservation of SULTR4 protein motifs across land species. A fluorescent protein fusion experiment confirmed that PsSULTR4 localizes to the vacuolar membrane.Five sultr4 mutants were identified by TILLING (Targeting Induced Local Lesions IN Genomes), two of which showe…

Role of vacuolar sulfate in the nutritional quality of pea seeds

Legumes have a key role to play in both agroecological and food transitions due to their ability to accumulate large amountsof seed proteins without nitrogen fertilization thanks to symbiotic N2 fixation in the root nodules. However, in agroecologicalsystems, legumes are more exposed to nutrient deficiencies, including sulfur deficiency, than in conventional systems, makingit important to optimize nutrient use efficiency for maintain seed protein quality, in particular the level of (semi) essentialamino acids like methionine and cysteine. These sulfur-containing amino acids are synthetized through the sulfur metabolicpathway starting from sulfate reduction. Sulfate is taken up from the soil…

Transcriptomic and metabolomic responses of the nodulated pea root system during rewatering

National audience; In pea (Pisum sativum), as in other legumes, nitrogen nutrition relies on two different sources: soil mineral nitrogen supply via roots and and symbiotic atmospheric N2 fixation within root nodules. However symbiotic nitrogen fixation is very sensitive to abiotic stresses, especially drought, which is becoming increasingly frequent in the current context of climate change. Although the ability of a crop to recover after a drought period can determine both its survival and its yield at harvest, little is known about the physiological and molecular mechanisms occurring during recovery. In this work, we aimed at characterizing the kinetics of growth and nitrogen acquisition …

Analyse écophysiologique de la récupération après un stress hydrique chez la légumineuse à graines Pisum sativum

National audience

Interplay between sulfur nutrition and water stress tolerance in pea : a focus on seed development and composition

International audience; Water stress and sulfur-deficiency are two constraints increasingly faced by crops due to climate change and low-input practices. To investigate their interplay in the grain legume pea (Pisum sativum L.), sulfate was depleted at mid-vegetative stage and a moderate 9-day water stress period was imposed during the early reproductive phase. The combined stress accelerated seed production, lowering yield, one-seed weight and seed number per plant, but rebalanced seed globulin composition. In fact, the moderate water stress mitigated the negative effect of sulfur-deficiency on the accumulation of sulfur-rich globulins in seeds, probably due to a lower seed sink strength f…

How does sulfur deficiency modulate pea response to water stress? Impact on early developing and mature seeds

National audience; Pea (Pisum sativum L.) produces seeds rich in proteins but yield and quality remain unstable across years due to various stresses. Sulfur (S) deficiency and water stress are two abiotic stresses that interact in the current context of climate change and low-input practices, and recent studies suggest an important role for sulfate transport and metabolism in the plant response to water stress. To investigate the interplay between sulfur nutrition and the water stress response, sulfate-deprived pea plants were subjected to a 9-days period of water stress during the early reproductive phase. While water stress did not impact seed yield, sulfur deficiency alone or combined wi…

Changes in the pea seed proteome in response to drought combined with sulfur deficiency

EABAPGEAPSI DOCT INRA; Pea (Pisum sativum L.) produces seeds rich in proteins, but seed yield and quality remain unstable across years due to abiotic stresses occurring during the reproductive period. Drought and sulfur deficiency are two abiotic stresses that interact in the current context of climate change and lowinput practices, and recent studies suggest a role of sulfate transport and metabolism in the plant response to drought (Ernst et al., 2010; Chan et al., 2013; Gallardo et al., 2014; Ahmad et al., 2016). In this study, we investigated the impact of sulfur deficiency combined with drought on the pea seed proteome. Pea plants were subjected to sulfur-deficiency two weeks after sow…

Le système racinaire nodulé du pois : un rôle pivot pour sa stabilité sous contraintes hydriques fluctuantes

National audience; Dans le contexte du changement climatique, des épisodes de stress hydrique plus fréquents sont attendus, entraînant des modifications de nutrition, de croissance des plantes, et donc des pertes de rendements. Chez les plantes légumineuses, telles que le pois protéagineux, un stress hydrique du sol diminue drastiquement l’acquisition de l’azote (N) par la fixation symbiotique du N2 atmosphérique, conduisant à une carence azotée de la plante et pouvant diminuer le rendement de 30 à 60% suivant les variétés. Il apparait donc nécessaire de sélectionner des génotypes de pois mieux adaptés à la sécheresse. Dans cette étude, les réponses architecturales, physiologiques et transc…

Adapter la composition protéique des graines de légumineuses en fonction des usages

National audience

Analyse protéomique des graines de pois en embryogénèse et à maturité : Impact d’un stress hydrique combiné à une carence en soufre

International audience

L'interaction entre la nutrition soufrée et la réponse du pois au stress hydrique

International audience

La génétique au service du goût : caractérisation de mutants pour l'accumulation de saponines et l'activité lipoxygènase dans la graines de pois (Pisum sativum)

International audience

Elucidating the genetic determinism of the plasticity of seed proteins in response to the environment using Medicago truncatula

International audience; Legumes are able to produce high-protein seeds without nitrogen fertilizer through root symbiosis with nitrogen-fixing rhizobia. Rich in lysine, these proteins are used for human nutrition and animal feed. However, instability of seed protein yield and quality due to environmental fluctuations limits the wide adoption of legumes in Europe. Breeding efforts are needed to optimize and stabilize seed nutritional quality. We have studied the plasticity of protein content and composition of seeds from a collection of 200 ecotypes of Medicago truncatula grown under four controlled conditions (optimal, drought, and winter/spring sowing). A quantitative analysis of one-dimen…

Etude du rôle de la nutrition soufrée dans la réponse du pois au stress hydrique par une approche protéomique : Focus sur les graines

International audience