0000000000928957
AUTHOR
Sylvie Girodet
Do pea nodulated roots have a memory like a sieve or like an elephant when faced with recurrent water deficits ?
National audience; In the current context of climate change, periods of water deficit occur more frequentlyalong the crop cycle, leading to high yield losses. To limit the negative impact of recurrentwater deficits, plants can adapt, via the mobilization of “stress memory”, allowing them torespond to a subsequent stress in a faster and/or more intensive manner. After a first stressevent, plants can keep an imprint of this stress via the induction of epigenetic (e.g. memorygene regulation), physiological (e.g. stomatal closure) and molecular (e.g. compoundaccumulation) changes. When maintained between two stress periods, these changes mayprepare plants for a subsequent water deficit.This wor…
Plant acclimation to high temperatures and water deficit: a comparative study determining independent and combined effects in four grain legume species
National audience; Four grain legumes species (Pea, Faba bean, Lentil and Lupin) were evaluated for their responses to high temperatures (HT) and soil water deficit (WD), applied independently or jointly. We characterized both nodulated root development and growth, as well as nodulated root performance in terms of water and N uptake. To that aim, plants inoculated with rhizobium were grown up to four weeks, corresponding to their vegetative stage, in innovative RhizoTubes© on the 4PMI high throughput phenotyping platform. Most of the traits, including overall plant performance illustrated by plant biomass, were more impacted by combined HT and WD than when these stresses were applied separa…
Can LCO and mycorrhiza mitigate the impact of water deficit on pea growth in co-inoculations with rhizobium? A preliminary assessment
National audience; Water stress is a major factor limiting production of legumes in Europe, but could be mitigated by improving interactions between plant roots and soil microbial communities, including symbiotic rhizobia and arbuscular mycorrhizal fungi. These two microbes produce lipochitooligosaccharide (LCO) signals, which stimulate symbiotic interactions and lateral root formation [1, 2]. While N2-fixation by rhizobia fulfills the plants N requirement [3], mycorrhizal fungi can improve mineral nutrition (P, N, S, K, Zn, Cu…) and water uptake [4- 5]. We have investigated in pea plants grown in interaction with a rhizobium strain, to what extent the negative impact of water deficit could…
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 …
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…
Does the memory of a first water deficit enable a more efficient response to a subsequent water deficit?
National audience; In the current context of climate change, periods of water deficit occur more frequentlyalong the crop cycle, leading to high yield losses. To limit the negative impact of recurrentwater deficits, plants can adapt, via the mobilization of “stress memory”, allowing them torespond to a subsequent stress in a faster and/or more intensive manner. After a first stressevent, plants can keep an imprint of this stress via the induction of epigenetic (e.g. memorygene regulation), physiological (e.g. stomatal closure) and molecular (e.g. compoundaccumulation) changes. When maintained between two stress periods, these changes mayprepare plants for a subsequent water deficit.This wor…
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…
Analyse écophysiologique de la récupération après un stress hydrique chez la légumineuse à graines Pisum sativum
National audience
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…
Root growth and development under heat and water stresses: a comparative study determining independent and combined effects in four grain legume species
International audience; hanks to their ability to fix atmospheric dinitrogen in symbiosis with soil bacteria, grain legumes provide a sustainable way to ensure food and nutritional security. Unfortunately, these crops are highly susceptible to environmental constraints such as heat or water stresses which leads to fluctuating yields as compared to cereals. In the context of climate change, more frequent episodes of heat stress, concomitant (or not) with water stress are expected. This emphasizes the need to identify key plant traits towards a better yield stability under stressful conditions.
Le pois lors de stress hydriques répétés : mémoire d’éléphant ou de poisson rouge ?
International audience; Dans le contexte actuel du changement climatique où les épisodes de déficits hydriques deviennent de plus fréquents et surviennent àdifférents stades au cours du cycle, les légumineuses à graines telles que le pois voient leur rendement fortement impacté. Afin de limiter lesimpacts négatifs de stress répétés, les plantes peuvent mettre en place une « mémoire » du stress, qui induit une modification de leur réponseà des stress ultérieurs. Cette mémoire dépend de plusieurs paramètres qui vont moduler l’ampleur et la rapidité de la réponse à un secondstress. Le premier stress peut induire des modifications épigénétiques, physiologiques (e.g. fermeture des stomates) et m…