Compositions and Positional Distributions of Fatty Acids in Phospholipids from Leaves of Chilling-Sensitive and Chilling-Resistant Plants

Abstract

The compositions and positional distributions of fatty acids in the major leafphospholipids of phosphatidylg lycerol, phosphatidylcholine and phosphatidylethanolamine were analyzed by gas-liquid chromatography and enzymic hydrolysis, and chilling-sensitive and chilling-resistant plants were compared with respect to the relative contents of palmitic and (ranj-jd3-hexadecenoic acids in the separated phospholipids. A distinct difference between these plants was found in the fatty acid compositions of phosphatidylglycerol, in which the sum of palmitic and trans-A 3-hexadecenoic acids ranged from 60 to 78% of the total fatty acids in 8 species of chilling-sensitive plants, and from 50 to 57% in 11 species of chilling-resistant plants. The only exception among the chillingsensitive plants in this respect was the tomato, in which the sum of palmitic and trans^]3-hexadecenoic acids in phosphatidylglycerol amounted to 54%. The fatty acid compositions and the positional distributions of fatty acids in phosphatidylg lycerol suggest that the occurrence of high proportions of dipalmitoyl and l-palmitoyl-2-((raRi-/J3hexadecenoyl) species in this lipid is correlated with the susceptibility to chilling of the leaves of higher plants. In the compositions and positional distributions of fatty acids in phosphatidylcholine and phosphatidylethanolamine, no difference was found between the chilling-sensitive and chilling-resistant plants.