Peach fruit (Prunus persica L. cv. Beijing 33) did not show symptoms of chilling injury in 0 degrees C-Air or 0 degrees C-CA, but did in 5 degrees C-Air after 21 d. The mechanisms by which 0 degrees C storage could activate chilling tolerance of peach fruit were investigated by analysing characteristics of plasma membrane. We found that peach fruit stored in 0 degrees C-Air and 0 degrees C-CA had much higher linolenic acid content and unsaturation degree of plasma membrane than did that in 5 degrees C-Air. In addition, the fruits stored in 0 degrees C-CA showed a higher membrane fluidity and membrane integrity than did that in 0 degrees C-Air, which was related to the accumulation of N-acylphosphatidylethanolamine (NAPE) of peach fruits stored in 0 degrees C-CA. Based on these results, it appears that a higher unsaturation degree of membrane lipid and NAPE accumulation are beneficial for maintaining membrane fluidity, leading to an enhanced tolerance of peach fruit to chilling stress. (C) 2009 Elsevier Ltd. All rights reserved.