Genome-wide association studies with proteomics data reveal genes important for synthesis, transport and packaging of globulins in legume seeds.
Improving nutritional seed quality is an important challenge in grain legume breeding. However, the genes controlling the differential accumulation of globulins, which are major contributors to seed nutritional value in legumes, remain largely unknown. We combined a search for protein quantity loci with genome-wide association studies on the abundance of 7S and 11S globulins in seeds of the model legume species Medicago truncatula. Identified genomic regions and genes carrying polymorphisms linked to globulin variations were then cross-compared with pea (Pisum sativum), leading to the identification of candidate genes for the regulation of globulin abundance in this crop. Key candidates identified include genes involved in transcription, chromatin remodeling, post-translational modifications, transport and targeting of proteins to storage vacuoles. Inference of a gene coexpression network of 12 candidate transcription factors and globulin genes revealed the transcription factor ABA-insensitive 5 (ABI5) as a highly connected hub. Characterization of loss-of-function abi5 mutants in pea uncovered a role for ABI5 in controlling the relative abundance of vicilin, a sulfur-poor 7S globulin, in pea seeds. This demonstrates the feasibility of using genome-wide association studies in M. truncatula to reveal genes that can be modulated to improve seed nutritional value.
Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), Université Bourgogne Franche-Comté, 21000, Dijon, France.
Christine
C
Le Signor
Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), Université Bourgogne Franche-Comté, 21000, Dijon, France.
Delphine
D
Aimé
Unité Mixte de Recherche (UMR) 1332 Biologie du Fruit et Pathologie, INRA, 33882, Villenave d'Ornon, France.
Amandine
A
Bordat
UMR 7286 - CRN2M, Centre d'Analyses Protéomiques de Marseille, CNRS, Aix-Marseille Université, Marseille, France.
Maya
M
Belghazi
INRA, UMR85 Physiologie de la Reproduction et des Comportements-Centre National de la Recherche Scientifique (CNRS) UMR 7247-Université François Rabelais-Institut Français du Cheval et de l'Equitation, Laboratoire de Spectrométrie de Masse, Plate-forme d'Analyse Intégrative des Biomolécules, 37380, Nouzilly, France.
Valérie
V
Labas
Laboratoire des Interactions Plantes-Microorganismes (LIPM), CNRS, INRA, Université de Toulouse, Castanet-Tolosan, France.
Jérôme
J
Gouzy
Department of Plant Pathology, University of Minnesota, St Paul, MN, 55108, USA.
Nevin D
ND
Young
Genetic Improvement and Adaptation of Mediterranean and Tropical Plants (AGAP), INRA, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Montpellier Supagro, 34060, Montpellier, France.
Jean-Marie
JM
Prosperi
Institut de recherche en horticulture et semences (IRHS), INRA, Agrocampus-Ouest, Université d'Angers, SFR 4207 QuaSaV, 49071, Beaucouzé, France.
Olivier
http://orcid.org/0000-0003-1414-8690
O
Leprince
Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), Université Bourgogne Franche-Comté, 21000, Dijon, France.
Richard D
RD
Thompson
Institut de recherche en horticulture et semences (IRHS), INRA, Agrocampus-Ouest, Université d'Angers, SFR 4207 QuaSaV, 49071, Beaucouzé, France.
Julia
J
Buitink
Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), Université Bourgogne Franche-Comté, 21000, Dijon, France.
Judith
J
Burstin
Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), Université Bourgogne Franche-Comté, 21000, Dijon, France.
Karine
K
Gallardo
D015180:Electrophoresis, Gel, Two-Dimensional; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D055106:Genome-Wide Association Study; D005916:Globulins / Q000235:genetics / Q000378:metabolism*; D046913:Medicago truncatula / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D005916:Globulins; D010940:Plant Proteins; D055314:Seed Storage Proteins; D014157:Transcription Factors; C015575:vicilin protein, plant

Medicago truncatula
; Pisum sativum (pea); genome-wide association studies (GWAS); globulins; legumes; protein quantity loci (PQL); seed proteome