Fatty acids in callus cultures: Influence of growth factors on fatty acid composition of total lipids in callus cells

Callus tissues were derived from cotyledon segments of Cucumis melo and Cucumis sativus. Four combinations of growth factors, i.e., naphthalene acetic acid (NAA) plus coconut water (CW); NAA plus kinetin; NAA plus 6-benzylaminopurine (BAP) and indole 3-butyric acid plus BAP, were incorporated in the medium for callus initiation as well as for growth of excised callus in culture for six passages. The proportion of total saturated to unsaturated acids and the ratio of linoleic to linolenic acid was influenced by the change in the type of auxin and cytokinin in the combinations used. A many fold increase of myristic acid was recorded for the indole 3-butyric acid plus BAP combination.     

Biochemical differences between embryogenic and nonembryogenic callus of Picea abies (L.) Karst

Both embryogenic and nonembryogenic calli of Picea abies (L.) Karst. were initiated from the hypocotyl region of immature embryos. The two callus phenotypes were manually separated and subsequently maintained independently, but under identical culture conditions. Biochemical analysis of the two phenotypes revealed significant differences in ethylene evolution rate and in concentrations of glutathione and total reductants. Due to the constancy of the genetic background, age and growth conditions of the two callus types, differences in the measured quantities are not likely to be traceable to the genetic origin of the callus and serve to highlight biochemical changes associated with somatic embryogenesis in Norway spruce.Abbreviations GSH glutathione - 2,4-D 2,4-dichlorophenoxyacetic acid - BA N⁶-benzyl adenine - E embryogenic - NE nonembryogenic - NS Norway spruce     

Morphohistobiochemical characteristics of embryogenic and nonembryogenic callus cultures of sweet potato (Ipomoea batatas L.)

Ipomoea batatas callus culture raised in a medium supplemented with 2,4-D (2,4-dichlorophenoxy acetic acid) alone or 2,4-D in combination with benzyl adenine, were found to be embryogenic. Supplementation of exogenous chemicals, such as 5 g/l NaCI or 0.7 g/l proline together with a mild dose of 0.2 mg/l 2,4-D, enhanced somatic embryogenesis significantly in all the genotypes tested. Morphological, growth, physiological, histological, and biochemical characteristics of the embryogenic callus were different from the nonembryogenic callus. The former was compact, slow growing, and nodular compared with the fast growing, fragile, nonembryogenic callus. The embryogenic callus tissue had more dry matter, protein and reducing sugar contents compared with the less embryogenic callus. The somatic embryogenic response remained steady in the cultures for up to 96 weeks.     

Fatty acid composition of total lipids and phospholipids of membrane preparations of transport ATPases

The fatty acid composition of total lipids and phospholipids of duck salt gland Na,K-ATPase (outer plasma membrane) and of rabbit skeletal muscle Ca-ATPase (intracellular membrane) was investigated. The bulk of Na,K-ATPase fatty acids is represented by palmitic (16:0), oleic (18:1), stearic (18:0) and arachidonic (20:4) acids. The duck salt gland is characterized by rather a high content of unsaturated fatty acids, especially of arachidonic acid. The unsaturation index of total-lipid fatty acids increases during purification of these preparations in the following order: homogenate greater than microsomal fraction greater than purified enzyme. The fatty acid composition of Na,K-ATPase total lipids and phospholipids reveals certain differences. Phospholipids contain more stearic and liholeic (18:2) acids than total lipids, but the level of arachidonic acid in them is twice as low. Besides, phospholipids were found to contain polyunsaturated docosohexaenic (22:6) acid. The bulk of fatty acids of rabbit skeletal muscle Ca-ATPase total lipids and phospholipids is represented by 16:0, 18:0, 18:1 and 18:2 acids. The content of polyunsaturated fatty acids in this preparation is much lower than in duck salt gland Na,K-ATPase. The fatty acid composition of total lipids and phospholipids in rabbit skeletal muscle Ca-ATPase differ insignificantly. The differences in the fatty acid composition of membrane preparations under study is conditioned mainly by the fractional composition of their lipids.     

Fatty acid composition of fern spore lipids

Fatty acid composition of lipids isolated from spores of different fern groups show differences between the families whereas species variations within the families are smaller. As in seed fats, the spore lipids are mainly triglycerides, with the exception of Osmunda where free fatty acids accumulate. The spore lipids contain as major components oleic, linoleic, and palmitic acid although those of the sporophylls contain C-20 polyunsaturated acids.     

Plant development in long-term embryogenic callus lines of Cucurbita pepo

Embryogenic callus derived from pumpkin hypocotyl segments was induced and maintained for 15 years on MS medium supplemented with the auxins IBA (4.9 M), 2, 4-D (4.5 M) or IAA (5.7 M). On induction media continued embryo maturation and development of adult plants typically failed. Therefore, small embryogenic clumps and individually isolated embryos were subcultured two to four times on one of the conversion media: MS supplemented with 1.5% sucrose and (a) no hormone, (b) 2.9 M IAA, (c) 5.7 M IAA, (d) 11.4 M IAA, (e) 12 M IEt, (f) 3.8 M ABA or (g) 2% activated charcoal. The cell line and the kind of auxin used in the induction and maintenance medium, both had a marked influence on the development of plantlets. The best result was achieved with a line that has been induced and maintained for 15 years on MS with IBA. In the IBA line, out of 100 embryos, 77 developed into plantlets on MS medium supplemented with 11.4 M IAA.Abbreviations IAA indole-3-acetic acid - IBA indole-3-butyric acid - BA 6-benzylaminopurine - ABA abscisic acid - 2, 4-D 2, 4-di-chlorophenoxyacetic acid - IEt indole-3-etha-nol - MS Murashige and Skoog (1962) medium     

Biochemical differences between embryogenic and nonembryogenic calli of conifers

Summary Embryogenic and nonembryogenic calli of loblolly pine (Pinus taeda), Eastern white pine (P. strobus), pond pine (P. serotina), white spruce (Picea glauca), and European larch (Larix decidua) were analyzed for biochemical parameters previously shown to be indicative of an embryogenic state in Norway spruce (Picea abies). Concentrations of glutathione and total reductants as well as rates of ethylene evolution and incorporation of radioactive leucine into protein in the two callus types were consistent with the Norway spruce observations. Embryogenic potential of loblolly pine and pond pine callus was predicted by biochemical analysis in advance of the appearance of somatic embryos. Other parameters such as isozyme patterns and SDS-PAGE of soluble proteins could also be used to distinguish embryogenic from nonembryogenic conifer callus. Among the species investigated, white spruce was the most difficult to sort by these methods.     

Fatty acid composition of the lipids of yeasts differing in radioresistance

The composition of membrane fatty lipid acids and the content of polyunsaturation of fatty acids have been shown not to be the leading factors in the formation of radioresistance cells.     

Fatty acid composition of lipids which copurify with band 3

In a previous study (L. R. Maneri and P. S. Low (1988) J. Biol. Chem. 263, 16170-16178) we determined that the anion transport protein, band 3, was significantly stabilized by lipids containing saturated and/or long chain fatty acids. To determine whether this thermodynamic preference is reflected in the composition of lipids tightly associating with the anion transporter in vivo, we have analyzed the fatty acid content of phospholipids co-isolating with the purified integral domain of band 3. Our data demonstrate that although stearic acid comprises only 14% of the bulk lipid fatty acids of the red cell membrane, it constitutes -68% of the fatty acids of lipids co-isolating with band 3. Certain other long chain fatty acids were also enriched in the adherent lipids. These results suggest that the fatty acids which most effectively stabilize band 3 also have the highest affinity for the transport protein.     

Fatty acid composition of Leptospira lipids as a taxonomic criterion

The fatty-acid composition of microbial cells in 17 pathogenic and saprophytic Leptospira strains, comprising 14 serovars and 10 serogroups, has been studied. The strains under investigation have proved to fall into 3 groups differing by this characteristic. The group of saprophytic strains is characterized by a comparatively high level of myristic acid and, consequently, by the ratio of saturated and unsaturated fatty acids with 14 carbon atoms approaching 1:1; besides, it is also characterized by a lower, in comparison with the pathogenic Leptospira strains belonging to the serogroups Icterohaemorrhagiae, Canicola, Ballum has a higher level of unsaturated fatty acids. The second group of pathogenic Leptospira strains including the serogroups Grippotyphosa, Hebdomadis, Pomona, Tarassovi, Pyrogenes, Australia has been found to occupy an intermediate position between the first group of pathogenic Leptospira strains and the group of saprophytic ones. As the difference in the content of myristic acid in pathogenic and saprophytic Leptospira strains is a stable characteristic, it can be used for the differentiation of these strains. The present investigation has revealed that the distribution of the main fatty acids in Leptospira phospholipids is similar to their distribution in Leptospira neutral lipids with the exception of unsaturated fatty acid with 14 carbon atoms, occurring mainly in phospholipids.     

Fatty acid composition of erythrocyte and vesicle total lipids during storage of human erythrocytes in protein-free media and in citrate-phosphate-dextrose

We have studied the fatty acid composition of total lipids of erythrocytes and vesicles either during storage of human erythrocytes in their own plasma under blood bank conditions or during incubation at 37 degrees C in protein-free media. Vesicles appear as a heterogeneous population with a diameter of about 130 nm and a varying content of hemoglobin. The fatty acid pattern of vesicle total lipids changes in respect to control erythrocytes, while in erythrocytes it remains fairly constant during the total ageing period. Our results indicate a marked rearrangement of the membrane components during blood storage.     

Fatty acid composition of total lipids from the needles of pine seedlings as related to boron availability

The effect of boron availability on the content of fatty acids (FA) in the total lipids of needles was investigated in two-year-old seedlings of Scots pine (Pinus sylvestris L.). The study was conducted in the forest nursery on the soil deficient in boron. Various rates of boric acid (0.01, 0.03, 0.1, 0.3, 1, 3, and 10 g/m²) were applied to soil three times throughout the growth period. When pine seedlings were supplied with extra boron, the lipid content of the seedling needles declined. The optimal boron supply elevated the content of saturated FA in total needle lipids mostly at the expense of palmitic acid, with a corresponding decline in the level of unsaturated FA and unsaturation index of FA owing to trienoic FA (mainly linolenic and hexadecatrienoic acids). At the same time, the level of monoenoic and to a lesser degree dienoic acids increased. When boron supply of the seedlings was not optimal, the content of unsaturated and low-molecular FA increased.     

Catabolism of putrescine and spermidine in embryogenic and non-embryogenic callus lines of Picea abies

The oxidation of putrescine and spermidine were studied in embryogenic and nonembryogenic cell cultures of Picea abies (L.) Karst., with [1,4-¹⁴C]-putrescine and [1,4-¹⁴C]-spermidine as substrates. Activities of putrescine and spermidine oxidation varied at every developmental stage in both cultures. Putrescine was oxidized ca 5 times as fast both in embryogenic and non-embryogenic tissue as spermidine. Diamine and especially polyamine oxidase activity increased markedly in both tissues towards the end of the culturing. In maturing embryos and in ageing non-embryogenic cultures, enzyme activities were lower than in non-differentiated embryogenic calli. Aminoguanidine (1 m M ) inhibited di- and polyamine oxidation in non-embryogenic tissue by >60% and >30%, respectively. The pH optimum for putrescine oxidation was 8.0, but in non-embryogenic tissue spermidine was degraded even more actively at pH 5.0. [¹⁴C]-Spermidine was catabolized to [¹⁴C]-putrescine. Pyrroline dehydrogenase activity was observed in non-embryogenic spruce tissue cultures.     

Fatty acid composition of the lipids of streptomycetes and their nocardia-like mutants

The models "population--Nocardia-like spontaneous mutants" for 14 cultures of Streptomycetes and Streptoverticillium were used to assess the fatty acid composition of lipids as a criterion for generic differentiation of Streptomyces and Nocardia cultures. The composition of fatty acids in the Nocardia-like mutant Str. kanamyceticus RIA-771 was found to be identical with that of Nocardia asteroides RIA-43 and Nocardia brasiliensis RIA-440, i. e. generic chemotaxonomic traits "overlapped" in the process of spontaneous intraspecial variability. In different strains of one and the same species as well as in five different species, the quantitative composition of fatty acids either hardly changed in the process of intraspecial variability or the ratio between fatty acids changed, so that Nocardia-like mutants resembled typical cultures of the Nocardia genus in this characteristics. The results suggest that the quantitative composition of fatty acids of lipids cannot be regarded as a sufficiently reliable criterion for generic differentiation of Steptomyces and Nocardia cultures. This trait should be used only for additional characterization of cultures.