Beyond the sequencing of the pea genome: opportunities for genomics-based breeding and translational approaches

International audience; The tribe Fabeae comprises more than 300 legume species, including some of the most ancient and important crops like Pisum sativum (pea), Lens culinaris (lentil), and Vicia faba (faba bean) used for food and feed. The genome sequence of pea, released in 2019, is an important milestone for the community working on legumes and especially on Fabeae. It brings into light evidences related to the genome expansion that occurred after the divergence of Fabeae from their sister tribes and highlights different chromosomal rearrangement events specific or not to the Pisum lineage. The pea genome sequence also represents a valuable resource to accelerate our understanding of th…

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…

Pea in the genomic era

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…

GRaSP project Genetics of Rhizobia Selection by Pea

Prod 2019-88aa; National audience; Because of their ability to fix nitrogen in symbiosis with soil bacteria, legumes such as peas have an important role to play in the development of a sustainable agriculture. However, in the field, biological nitrogen fixation (BNF) could be suboptimal as natural Rhizobium leguminosarum viciae (Rlv) populations are quantitatively and qualitatively heterogeneous, with strains varying in their competitiveness and efficiency of BNF [1,2]. There is a general agreement concerning the interest of Rlv inoculation for improving BNF and thus pea yield [3]. However, even when pea seeds are inoculated by efficient Rlv strains these can be outcompeted by indigenous rh…

Taking cool-season grain legume breeding to the next level: the key role of the pea genome sequence

International audience; The transition from a standalone phenotypic selection to a marker-assisted selection has been seen as a great step forward to improve the breeding process and reach the expected goals. More recently, the genomic revolution has also had its great impact on breeding. -omics are now part of the required toolkit for a successful, cost and time-efficient breeding. The genome sequence of pea (Pisum sativum) has been made available in 2019 through a collaborative international effort. This is a great tool for the pea community in general and the Fabeae community in particular. Current challenges facing pea and other Fabeae production are numerous. A large number of traits h…

Genetic diversity of nodulated root structure in a very diverse pea collection

National audience; The root system is responsible for nitrogen (N) acquisition, which in legumes, combines mineral acquisition and symbiotic fixation in nodules. Despite these two complementary pathways, N nutrition may be a limiting factor of legumes yield because nodules are very sensitive to their local environment and N fixing legume root system is poorly developed which may limit soil exploration [1]. Pea establishes in root nodules a symbiotic association with Rhizobium leguminosarum sv viciae bacteria (Rlv) [2]. This study assessed the potential of naturally occurring genetic variability of nodulated root structure and functioning traits to improve yield pea performance. Two successi…

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.