Plant lipid droplets in post-stress recovery – RecovOil
While global climate changes significantly affect crop yields, our understanding of plant tolerance to adverse environmental conditions still remains limited. The transient accumulation of triacylglycerols (TAGs) in organelles called lipid droplets (LDs) is considered as an essential cellular adaptation to stress, associated with better survival upon stress termination. In plants, TAG accumulation and LD proliferation are reported in response to a wide range of environmental stresses, including heat and nitrogen deprivation. However, how stress-accumulated lipids are degraded and contribute to membrane and energy homeostasis during the stress recovery phase remains completely unknown. Whether different stresses lead to distinct lipid metabolic adaptations and specific LD remobilization pathways is also a central but unresolved question. Another unaddressed issue is whether distinct pools of LDs coexist within a cell to fulfil specific functions in energy supply or membrane/organelle reshaping.
The 4-year RecovOil project proposes an transdiplinary experimental program to address these issues and to elucidate the functions of LDs during stress recovery. Notably, the project aims to characterize the mechanisms of stress-induced LD remobilization and their importance in plant stress tolerance, by exploring the respective contribution of lipolysis and lipophagy and by determining whether the LD degradation pathways are specific to stress type (heat vs N deprivation) and developmental stage (young adult plants vs young seedlings). To answer the latter question, three experimental Arabidopsis thaliana systems will be investigated throughout the project : plantlet upon recovery from N deprivation, plantlet upon recovery from heat stress, and seedling upon recovery from heat stress.
Overall, the RecovOil project is divided into 3 scientific workpackages organized by a management workpackage, which will provide independent and integrated results along the three following objectives: (1) unravel how LDs contribute to changes in lipid metabolism/membrane homeostasis during post-stress recovery ; (2) understand LD populations and dynamics during stress recovery ; (3) identify and characterize the molecular mechanisms involved in LD degradation and lipid remobilization. By aggregating the complementary expertise of four teams in LD biology, lipid metabolism, stress and autophagy research, this project will mobilise a combination of state-of-the art approaches combining lipidomics, fluxomics, proteomics to cellular/molecular biology and plant physiology to characterize the pathways and molecular mechanisms underlying LD degradation and its metabolic and physiological relevance during stress recovery. This project will thus contribute to a better understanding of how plants adapt to environmental stress, a crucial issue in the current context of global climate changes.
Madame Sabine D'Andrea (Institut Jean-Pierre BOURGIN)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
IJPB Institut Jean-Pierre BOURGIN
LBM Laboratoire de biogenèse membranaire
Help of the ANR 551,546 euros
Beginning and duration of the scientific project: November 2021 - 48 Months