Cyclopropane Fatty Acids in Relation to Earliness in Spring and Drought Tolerance in Plants

Abstract

Long chain cyclopropane fatty acids were observed in the sulfolipid fraction extracted from leaves of the early spring plants Galanthus nivalis L. and Anthriscus silvestris L.(Hoffm. The lipids were extracted from the leaves as described by Allen et al. (1) for spinach leaves and separated on a diethylaminoethyl cellulose column (1,9,14). Separation of the fractions of phosphatidyl glycerol, sulfolipid, and phosphatidyl inositol sometimes was incomplete, but doubtful test tubes were discarded. Purity of the lipids was checked by thin layer chromatography (14).The lipids were deacylated with methanolic KOH (17). The fatty acids were methylated with 10% BCl, in methanol (12) and analyzed on a Victoreen gas chromatograph with a hydrogen flame ionization detector. The column was composed of 15% diethylene glycol succinate on Anakrom 60/70 as a stationary phase. Because of the wide range of fatty acids observed, from 12 carbon atoms (lauric acid) to 25 carbon atoms (cyclopropane fatty acid) in the hydrocarbon chain, the samples were run at two different temperatures, 180 and 200 C, to obtain an accurate analysis. Also, samples were run in different amounts, because the retention time of very long chain fatty acids was slightly affected by the amount of fatty acid methyl ester injected on the column. All fatty acid methyl esters were identified with known fatty acid methyl esters, or the retention times were compared with literature data (5-7). For determination of long chain unsaturated fatty acids, samples were analyzed by gas chromatography and the remaining part of the samples was dissolved in methanol and hydrogenated with palladium oxide as a catalyst for 6 hr at room temperature. After evaporation of the methanol the hydrogenated sample was analyzed by gas chromatography and a comparison was made between the original and the hydrogenated sample.Cyclopropane fatty acids were detected after treatment of the fatty acid methyl ester sample with bromine in ether at 30 C (2). Ether and excess bromine were evaporated. Further identification of the cyclopropane fatty acid was carried out by strong hydrogenolysis of samples in glacial acetic acid at 50 C for 4 hr with palladium oxide as a catalyst (7), converting them to methyl-branched fatty acids which differ in retention time. Table I shows the fatty acid composition of the sulfolipid fraction of the leaves of the early spring plants studied. The 307 www.plantphysiol.org on May 7, 2018 -Published by Downloaded from RESULTS AND DISCUSSION

Effect of Frost Hardening on Lipid and Fatty Acid Composition of Chloroplast Thylakoid Membranes in Two Wheat Varieties of Contrasting Hardiness

“…Such extralong-chain fatty acids in the thylakoid SL fraction could contribute to low temperature tolerance of the light-dependent proton uptake; SL itself is the most effective lipid in protection of chloroplast coupling factor to low temperature damage (8). The above observation also is in agreement with data on early spring plants, which show a direct relation between SL esterified with fatty acids of 20 or more C atoms and growth of the plant at low temperature (6). Further interpretation of the adaptive value of the thylakoid glycolipid changes in low temperature tolerance of light-dependent proton uptake is only possible when the presence of these lipids in the thylakoid proton channels has been established.…”

Metabolism of cyclopropane fatty acids by Tetrahymena pyriformis

“…CPAs are also reported in the seedlings of species of the order I«lalvales (Hooper and Law, I965;Johnson et al, 1967) and in small amounts in all other tissues of the same plants (Yano et al, 1972a). Long chain CPAs with 25 carbon atoms were observed recently by Kuiper and Stuiver (1972) and wheat (Triticum estivum L.). Several other CPAs (Cg^y C22' ^23 ^25^ were also reported by the same authors to occur in the drouth-tolerant Corynephorus canescens.…”

“…Comparison of the fatty acid composition of the glyco-, phospho-, and sulfolipids of the early spring plants snow drop and rye (Kuiper and Stuiver, 1972) showed that CPAs were only found in the sulfolipid fractions of both species, and a small amount in the phosphatidylinositol fraction of snow drop. The same author also observed that the drouthtolerant species Ç. canescens contains CPAs only in the phos phatidylcholine fraction.…”

“…Cis-9.10-methvlenehexadecanoic acid was twice as inhibitory as the mono-0lefinie acids. Henderson and McNiell (1966) (Kuiper and Stuiver, 1972). It is known that chilling resistance in plants is correlated with high flexibility of mitochondria and with a high degree of unsaturation of the mitochondrial lipids (Lynos and Raison, 1970;Lynos et al , 1964 …”

“…;Kleiman et al, 1968;Yano et al, 1972a;Kuiper and Stuiver, 1972) and protozoa (Meyer and Holz, 1966). They have been also detected in the millipede Graphidostreptus tumuliporus (Oudejans et al, 1971; Van der Horst et al, 1972) and in sheep rumen tissue (Brody, 1972).…”