Lipidome remodeling during cold acclimation is controles by plasma membrane associated synaptotagmins

Abstract

The lipidome remodeling during cold acclimation is an important evolutionary milestone to plant adaption to sub-optimal temperature conditions. In Arabidopsis, the phospholipid binding protein Synaptotagmin1 (SYT1) maintains the plasma membrane (PM) integrity during abiotic stress (1, 2) , participates in the Ca2+-dependent acquisition of freezing tolerance (3), and it is involved in viral protein cell-to-cell movement (4). Despite these important roles, its PM delivery mechanisms, lipid membrane targets, and in vivo effects on lipid composition have been largely overlooked. In this report (5), we establish that SYT1 is an ER and PM associated protein that specifically binds negatively charged phosphoinositides and glycerolipids, and its loss causes the over-accumulation of its phospholipid binding partners in vivo. We also present a preliminary characterization of SYT3, an additional phospholipid binding member of the Arabidopsis SYT family, as a unique stress inducible determinant required for lipidome remodeling during cold stress episodes.