Les miRNAs jouent un rôle crucial dans la régulation des fonctions cellulaires en particulier en réponse aux contraintes environnementales

The pan-transcriptome of Vicia faba

Vicia faba (faba bean) is a nitrogen-fixing protein crop that, in contrast to soya bean, yields well in temperate climates. It is diploid but has a very large genome of ~13 Gb, and genomic resources are currently limited. To provide a high-quality reference gene set and expression atlas, we have carried out RNA-seq of multiple tissues from five faba bean accessions. For each tissue, an assembly was produced using the Trinity software package using both Illumina and PacBio reads. For each accession, the assemblies were then merged to create a more complete reference gene set. The assemblies were of high quality, with more than 95% complete BUSCOs [1] and read mapping rates of ~90%. The assem…

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…

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…

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…

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 …

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…

The faba bean pan-transcriptome

Faba bean (Vicia faba) is a widely adapted nitrogen fixing grain legume that produces seeds with high protein content. It is an agriculturally attractive crop with a good disease resistance profile, but targeted breeding is hampered by the lack of a reference genome and gene set. Here we develop a faba bean gene expression atlas and pan-transcriptome. The pan-transcriptome was generated using data from four different accessions (Hedin, Hiverna, 153b, 2378), including data from both aerial and root tissues. The quality and utility of the pan-transcriptome was assessed by mapping reads from accessions that had not contributed data to the pan-transcriptome. Here, the high mapping rates suggest…

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…