The Arabidopsis hit1-1 mutant has a plasma membrane profile distinct from that of wild-type plants at optimal growing temperature.

High temperatures alter the physical properties of the plasma membrane and cause loss of function in the embedded proteins. Effective membrane and protein recycling through intracellular vesicular traffic is vital to maintain the structural and functional integrity of the plasma membrane under heat stress. However, in this regard, little experimental data is available. Our characterization of the Arabidopsis hit1-1 mutant, linking a subunit of a vesicle tethering complex to plasma membrane thermostability, provided valuable information to this end. We further dissected the effect of the hit1-1 mutation on plasma membrane properties and found that even at optimal growth temperature (23 °C), the hit1-1 mutant exhibited a plasma membrane protein profile distinct from that of wild-type plants. This result implies that the hit1-1 mutation essentially alters vesicle trafficking and results in changes in the plasma membrane components under non-stress conditions. Such changes do not affect normal plant growth and development, but is significant for plant survival under heat stress.