Root lipid homoeostasis under cold temperature

• Applicant: Dr. Ana Carolina Vilchez, Ph.D.
• Subject Area: Plant Biochemistry and Biophysics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 560830917

Cold events driven by climate change post a challenge for plants leading to severe yield reductions. Improving plants in the future requires us to understand the basic principles of their adaptative mechanisms. Lipid remodeling in response to temperature stress is pivotal for cellular homeostasis. Triacylglycerol (TAG) accumulation in lipid droplets (LDs) is a hallmark in plant responses to abiotic stress, but its physiological relevance and the underlying metabolic mechanisms in vegetative tissues, are poorly understood. We found that the number and size of TAG storing LDs increase under low temperature stress in Arabidopsis roots, followed by a decrease during the recovery period. Additionally, the loss of lysophosphatidylcholine acyltransferase (LPCAT), an enzyme involved in phosphatidylcholine remodeling, reduces the LD cold response and reduces the plants fitness under cold. This allowed us to hypothesize that stress-driven LDs might serve as reservoirs for membrane lipid remodeling products, which would affect LDs composition and contribute to their increased size and quantity. In this way, LDs increment will help to regulate membrane fluidity under stress and its mobilization will support recovery phase. The Walter Benjamin program would give me the opportunity to investigate in detail the TAG metabolism and its relevance for lipid homeostasis under temperature stress in roots. Within this scope of this project, I plan to (i) address TAG dynamics by analyzing LD’s lipid and protein profile under cold stress and mobilization during recovery and (ii) decipher the role of LPCAT1 and 2 in root lipid homeostasis under stress by evaluating their impact on membrane and LDs composition and properties.

• DFG Programme: WBP Position