Studying the interplay between sulfur nutrition and water stress tolerance in pea by proteomics : a focus on seed development and composition
Résumé
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 protein composition. In fact, the
moderate water stress mitigated the negative effect of sulfur-deficiency on the accumulation of sulfurrich
proteins in seeds, probably due to a lower seed sink strength for nitrogen, enabling a readjustment
of the sulfur-poor/sulfur-rich globulin ratio. These results uncovered the importance of sulfur for
stabilizing seed yield in pea facing short and moderate water stress episodes, and showed that the
adaptive response of sulfur-deprived plants to water stress is much more complicated than a simple
additive response. Developing seeds were subjected to shotgun proteomics and transcriptomics to
advance our knowledge of the seed response to the single or double stresses. Among the results that
will be presented is the building of a protein network together with a differential analysis, highlighting
hubs potentially implicated in seed development and stress response.