MPI-MP AUTUMN SERIES: Sequestration of Arabidopsis florigen FT in the cellular membrane modulates temperature-responsive flowering - Hendry Susila

Plants respond to temperature changes by modulating florigen activity to optimize the timing of flowering. Here, we show that the Arabidopsis thaliana mobile florigen FLOWERING LOCUS T (FT) interacts with the negatively charged phospholipid phosphatidylglycerol (PG) at cellular membranes and binds the lipid bilayer. Perturbing PG biosynthesis in phloem companion cells leads to temperatureinsensitive early flowering. Low temperatures facilitate FT sequestration in cellular membranes of the companion cell, restricting the mobility and thus delaying flowering. A mutant in PHOSPHATIDYLGLYCEROLPHOSPHATE SYNTHASE 1 accumulates more soluble FT at lower temperature and exhibits reduced temperature sensitivity. Therefore, our work reveals that cellular membranes sequester FT through its ability to bind the phospholipid PG as a new mechanism in the plant response to temperature changes.

Plants respond to temperature changes by modulating florigen activity to optimize the timing of flowering. Here, we show that the Arabidopsis thaliana mobile florigen FLOWERING LOCUS T (FT) interacts with the negatively charged phospholipid phosphatidylglycerol (PG) at cellular membranes and binds the lipid bilayer. Perturbing PG biosynthesis in phloem companion cells leads to temperatureinsensitive early flowering. Low temperatures facilitate FT sequestration in cellular membranes of the companion cell, restricting the mobility and thus delaying flowering. A mutant in PHOSPHATIDYLGLYCEROLPHOSPHATE SYNTHASE 1 accumulates more soluble FT at lower temperature and exhibits reduced temperature sensitivity. Therefore, our work reveals that cellular membranes sequester FT through its ability to bind the phospholipid PG as a new mechanism in the plant response to temperature changes.