An increase in both the content of soluble sugars and a higher
ratio of unsaturated membrane fatty acids occurred in plants after
cold acclimatisation periods in our study, and this was related to
increased frost tolerance. The main observed change in fatty acid
content in cold acclimatised kale leaves, was the overall reduction
of the total unsaturated fatty acids. The highest frost tolerance
among non-acclimatised plants was observed in plants grown at
the lower temperatures (15/9 C). This treatment did not have
the highest content of either unsaturated fatty acids or soluble sugars,
suggesting that frost tolerance in non-acclimatised plants is
not directly linked to the level of soluble sugars and unsaturated
fatty acids. However, the ratio of unsaturated versus membrane
fatty acids palmitic acid (16:0) + stearic acid (18:0) increased after
cold acclimatisation, which together with decreased ion leakage