Effets physiologiques de l'atrazine à doses sublétales sur Lemna minor L. IV. Influence sur la composition lipidique

1979 ◽  
Vol 57 (9) ◽  
pp. 1015-1020 ◽  
Author(s):  
G. Grenier ◽  
J. P. Marier ◽  
G. Beaumont

The lipids and the fatty acids of duck weed (Lemna minor L.), cultivated aseptically during 5, 10, or 15 days in mineral solution containing sublethal concentrations of atrazine (0.05 to 0.75 ppm), were analysed by thin-layer and gas–liquid chromatography. All concentrations of atrazine used, independently of age of plants, increased the total fatty acid content, except for 5-day plants at 0.50 and 0.75 ppm atrazine where a decrease in total fatty acids was observed. α-Linolenic acid content increased while linoleic acid content decreased. Sublethal concentrations of atrazine increased the percentage of monogalactosyldiacylglycerol compared with total phospholipids and total neutral lipids. Monogalactosyldiacylglycerol was the main lipid involved in the α-linolenic acid increase observed in the total fatty acids. The increase in α-linolenic acid and in monogalactosyldiacylglycerol in the presence of sublethal concentrations of atrazine is an indication that these treatments maintain intact and fully functional chloroplast membranes.

1982 ◽  
Vol 60 (6) ◽  
pp. 758-764 ◽  
Author(s):  
R. Bérubé ◽  
G. Beaumont ◽  
G. Grenier

Doses from 0.002 to 2.0 ppm of benzyladenine (BA) increased the water content in 15-day-old plants of Lemna minor L. However, a concentration of 5.0 ppm decreased it. The total esterified fatty acid content increased up to 2.0 ppm and decreased at 5.0 ppm, compared with controls. The BA increased the percentages of total palmitic and α-linolenic acids and decreased the percentage of total linoleic acid, mainly for higher doses. At 2.0 and 5.0 ppm of BA, the proportions of phospholipids increased strongly as compared with galactolipids (especially the diacylgalactosylglycerol) and total neutral lipids. In phosphatidylcholine, phosphatidylethanolamine, and phosphotidylinositol, the α-linolenic acid content exhibited a marked increase at the expense of linoleic acid of these phospholipids. The percentage of α-linolenic acid in diacylgalactosylglycerol remained constant in the presence of BA, but it decreased in diacyldigalactosylglycerol. At concentrations of 2.0 and 5.0 ppm, the α-linolenic acid content of total neutral lipids increased greatly. The modifications observed in the lipid composition of L. minor, at 2.0 and 5.0 ppm in BA, suggest that the cell membranes (particularly those of chloroplasts) and their functions may be altered by these high doses of cytokinin.


OENO One ◽  
1980 ◽  
Vol 14 (3) ◽  
pp. 147
Author(s):  
J. J. Lavaud ◽  
Monique Cherrad

<p style="text-align: justify;">Cinq catégories de pépins de Cabernet Sauvignon ont été séparées à la véraison. Plus de 95 p. 100 des acides gras sont contenus dans les lipides neutres. La différence de composition en acides gras des lipides polaires montre que la localisation des pépins dans une seule loge ou dans deux loges séparées a pour conséquence une modification du fonctionnement des désaturases.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Five categories of Cabernet Sauvignon seeds were separated at the beginning of ripening. The neutral lipids contain more than 95 per cent of the fatty acids. The difference in the fatty acid content of polar lipids shows that seeds localized in just one section or in two separate sections results in a modification of the « desaturase » functioning.</p>


2016 ◽  
Vol 69 (4) ◽  
Author(s):  
Józef Klocek ◽  
Magdalena Szwed ◽  
Danuta Koczkodaj ◽  
Joanna Mitrus ◽  
Marian Saniewski ◽  
...  

The effect of methyl jasmonate (MJ) vapors on the composition and peroxidation of major fatty acids in the organs of common buckwheat seedlings was investigated. The composition of fatty acids in the hypocotyl and cotyledons of seedlings changed significantly under exposure to MJ vapors in closed jars. Four-day exposure to MJ led to a significant reduction in the concentrations of stearic, linoleic, and linolenic acids in the hypocotyl, whereas oleic acid levels increased approximately 3.5-fold. A decrease in stearic acid levels and an increase in the content of linolenic acid were noted in cotyledons, whereas oleic acid levels decreased in roots. Seven-day exposure to MJ vapor caused a further reduction in stearic acid content and an increase in oleic acid and linoleic acid levels in the hypocotyl. At the same time, the linoleic acid content of roots and linolenic acid levels in cotyledons were doubled, but a 5-fold reduction in linolenic acid concentrations was observed in roots. Methyl jasmonate intensified fatty acid peroxidation in cotyledons after 4 and 7 days and in roots after 4 days of exposure. Peroxidation was inhibited in the hypocotyl and roots after 7 days. The noted changes in the composition and peroxidation of fatty acids are probably indicative of senescence in buckwheat seedlings under the influence of MJ. Senescence seems to proceed faster in cotyledons than in other organs of buckwheat seedlings.


Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 57-60 ◽  
Author(s):  
A. E. Smith ◽  
R. E. Wilkinson

Chloroplasts, isolated from fresh spinach (Spinacia oleracea L.) were treated with four concentrations of each 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) or 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) to determine the influence of these herbicides on the free fatty acid content in isolated chloroplasts. The treated chloroplast solutions were sampled at 0, 5, 15, 30, 60, and 120 min following treatment. Results indicated that most herbicide treatments increased free fatty acid content in isolated chloroplasts when compared with the zero concentration treatments. The increased fatty acid content was similar for most concentrations of simazine and atrazine. Results of individual fatty acid analyses indicated that the increase in total fatty acids was a result of increases in concentration of unsaturated rather than saturated fatty acids.


Weed Science ◽  
1969 ◽  
Vol 17 (3) ◽  
pp. 335-338 ◽  
Author(s):  
R. E. Wilkinson ◽  
W. S. Hardcastle

Total petiolar fatty acid content of sicklepod (Cassia obtusifoliaL.) treated with 0, 0.14, 0.28, 0.56, 1.12, 2.24, or 4.48 kg/haS-ethyl dipropylthiocarbamate (EPTC) was measured by gas-liquid chromatography. Neither total petiole fatty acid content nor percentages of the various 53 identified constituents changed in relation to herbicide application. Isostearate (17.5%), stearate (5.7%), oleate (5.7%), linolate (9.8%), and arachidate (8.2%) accounted for 46.9% of the total petiole fatty acid content. Anteiso derivatives of C15to C31were identified and quantitated at concentrations of 0.25 to 2.00%. Petiole cuticle thickness decreased 35% as herbicide concentration increased to 4.48 kg/ha.


2001 ◽  
Vol 71 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Christine Pereira ◽  
Duo Li ◽  
Andrew J. Sinclair

Green vegetable consumption has long been considered to have health benefits mainly due to the vitamins, minerals and phytonutrients (such as vitamin C, folate, antioxidants etc) contained in a vegetable-rich diet. Additionally, green vegetables are known to contain a relatively high proportion of omega-3 polyunsaturated fatty acids (PUFAs), primarily in the form of alpha-linolenic acid (18:3n-3). However, there are no data available on the fatty acid composition and concentration of green vegetables commonly consumed in Australia. The present study determined the fatty acid content of 11 green vegetables that are commonly available in Australia. The total fatty acid concentrations of the vegetables under study ranged from 44 mg/100 g wet weight in Chinese cabbage to 372 mg/100 g in watercress. There were three PUFAs in all vegetables analyzed; these were 16:3n-3, 18:2n-6, and 18:3n-3 fatty acids. Sample vegetables contained significant quantities of 16:3n-3 and 18:3n-3, ranging from 23 to 225 mg/100g. Watercress and mint contained the highest amounts of 16:3n-3 and 18:3n-3, and parsley had the highest amount of 18:2n-6 in both percentage composition and concentration. Mint had the highest concentration of 18:3n-3 with a value of 195 mg/100 g, while watercress contained the highest concentration of 16:3n-3 at 45 mg/100 g. All 11 green vegetables contained a high proportion of PUFAs, ranging from 59 to 72% of total fatty acids. The omega-3 PUFA composition ranged from 40 to 62% of total fatty acids. Monounsaturated fatty acid composition was less than 6% of total fatty acids. The proportion of saturated fatty acids ranged from 21% in watercress and mint to 32% of total fatty acids in Brussels sprouts. No eicosapentaenoic and docosahexaenoic acids were detected in any of the samples. Consumption of green vegetables could contribute to 18:3n-3 PUFA intake, especially for vegetarian populations.


2007 ◽  
Vol 73 (21) ◽  
pp. 6965-6971 ◽  
Author(s):  
Hisashi Yazawa ◽  
Hitoshi Iwahashi ◽  
Yasushi Kamisaka ◽  
Kazuyoshi Kimura ◽  
Tsunehiro Aki ◽  
...  

ABSTRACT To make dihomo-γ-linolenic acid (DGLA) (20:3n-6) in Saccharomyces cerevisiae, we introduced Kluyveromyces lactis Δ12 fatty acid desaturase, rat Δ6 fatty acid desaturase, and rat elongase genes. Because Fad2p is able to convert the endogenous oleic acid to linoleic acid, this allowed DGLA biosynthesis without the need to supply exogenous fatty acids on the media. Medium composition, cultivation temperature, and incubation time were examined to improve the yield of DGLA. Fatty acid content was increased by changing the medium from a standard synthetic dropout medium to a nitrogen-limited minimal medium (NSD). Production of DGLA was higher in the cells grown at 15�C than in those grown at 20�C, and no DGLA production was observed in the cells grown at 30�C. In NSD at 15�C, fatty acid content increased up until day 7 and decreased after day 10. When the cells were grown in NSD for 7 days at 15�C, the yield of DGLA reached 2.19 μg/mg of cells (dry weight) and the composition of DGLA to total fatty acids was 2.74%. To our knowledge, this is the first report describing the production of polyunsaturated fatty acids in S. cerevisiae without supplying the exogenous fatty acids.


2001 ◽  
Vol 73 (2) ◽  
pp. 253-260 ◽  
Author(s):  
K. Raes ◽  
S. de Smet ◽  
D. Demeyer

AbstractThe effect of double-muscling (DM) genotype (double-muscling, mh/mh; heterozygous, mh/+; normal, +/+) of Belgian Blue (BB) young bulls on the intramuscular fatty acid composition, in particular conjugated linoleic acid (CLA) and polyunsaturated fatty acids (PUFA) was examined in five different muscles. The relative fatty acid composition showed only minor differences between muscles within genotypes. However, the DM genotype had a large effect on both the intramuscular total fatty acid content and on the relative fatty acid composition. Across muscles, the mh/mh animals had a lower total fatty acid content compared with the +/+animals (907 v: 2656 mg/100 g muscle;P< 0·01) and a higher PUFA proportion in total fatty acids (27·5 v 11·3 g/100 g total fatty acids;P< 0001), resulting in a higher PUFA/saturated fatty acid ratio (0·55 v 0·18;P< 0·01) and a lower n-6/n-3 ratio (5·34 v. 6·17;P< 0·01). The heterozygous genotype was intermediate between the two homozygous genotypes. The relative CLA content was similar in the mh/mh and +/+ genotypes and approximated 0·4 to 0·5 g/100 g total fatty acids. From the data it is further suggested that differences in the metabolism of the n-3 and n-6 fatty acids could exist between DM genotypes.


Sign in / Sign up

Export Citation Format

Share Document