Comparison of fatty acid patterns in plant parts and respective callus cultures of Cucumis melo

Root, hypocotyl, cotyledon, stem and leaf of Cucumis melo var. utilissimus seedlings were used for callus induction. Comparison was made between these parts, between callus tissues originating from all the parts and between each part and its callus, with respect to the fatty acid composition of total lipids. In all the parts there was a greater proportion of unsaturated fatty acids, the predominant fatty acid in root, stem and leaf being linolenic acid whilst in the cotyledon linoleic predominated. In the hypocotyl these two acids were present in equal amounts. In callus cultures the proportion of saturated acids was greater and the predominant fatty acid was palmitic. The major unsaturated fatty acid in callus cultures was linolenic. The analysis showed that callus tissue and its respective plant part had different fatty acid patterns and that all the callus cultures had very similar patterns irrespective of their origin.     

Fatty acids in callus cultures: Stage of reversal in the proportion of unsaturated to saturated acids and of change in major components

The lipids of the cotyledon of Cucumis melo contain a large proportion of unsaturated fatty acids with linoleic acid as the major component, whereas those of cotyledon callus show a marked reduction in linoleic acid, an increase in linolenic acid and a predominance of palmitic acid which results in an increase in total saturated acids. The fatty acid compositions of total lipids in the cotyledons at different stages of seedling development, excised cotyledon tissue at different stages of callus initiation and in isolated callus show that the observed changes manifested in the established callus occur in the newly formed meristimatic cells as a result of the action of growth substances used for callus initiation.     

Fatty acid composition of lipids from differentiated tissues and cell cultures of Euonymus europaeus

The fatty acid patterns of Euonymus europaeus callus cultures and cell suspension cultures were analysed at the beginning of stationary growth phase and compared with those from the respective differentiated tissues. The lipid and fatty acid patterns in cell cultures differed remarkably from those in the tissues of the mother plant. No glycerol triacetate was detected in the callus cultures derived from differentiated tissues whereas in seeds this lipid compound amounts to 29%. In addition to fatty acids normally occurring in differentiated tissues, lipids in cultured cells also contained short-chain (C₁₂–C₁₄) as well as very long-chain fatty acids (C₂₀–C₂₄). In tissue culture cells the major fatty acids were found to be saturated, whereas in the mother cells unsaturated fatty acids were predominant. Palmitic acid is the most abundant fatty acid in most of the cultures. Lauric, myristic and palmitic acid amount to 50% in lipids of cell suspension cultures.     

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.     

Lipids in plant tissue cultures. VI. Effect of temperature on the lipids of Brassica napus and Tropaeolum majus cultures

The lipid contents of callus cultures of rape (Brassica napus) and nasturtium (Tropaeolum majus) increase in response to decreasing the temperature, though to different degree. Irrespective of the incubation temperature the lipids in cultures of both plants contain as predominant classes steryl glycosides, esterified steryl glycosides, sterols, steryl esters and fatty acids and, as minor constituents, various proportions of triacylglycerols, phospholipids and several unidentified fractions.The ratio of phospholipids to triacylglycerols as well as the ratio of diacylglycerophosphorylethanolamines to dicylglycerophosphorylcholines increase with time both in rape cultures incubated at 30°C and in those kept at 5°C.The lipids in rape and nasturtium cultures grown at 30°C contain smaller proportions of polyunsaturated fatty acids than the lipids in cultures incubated at 5°C. Erucic acid, the major constituent fatty acid of the seed lipids, in both plants, occurs only in trace amounts in the lipids of callus cultures. In contrast, linoleic and linolenic acids, which occur only in traces in the seed lipids of nasturtium, are major constituent fatty acids in the lipids of callus cultures derived from seedlings of this plant.The levels of constituent polyunsaturated fatty acids in the diacylglycerophosphorylethanolamines and the diacylglycerophosphorylcholines increase with time whereas in the triacylglycerols only linolenic acid is slightly increased.     

Biogenesis of mitochondria: The effects of altered steady-state membrane lipid composition on mitochondrial-energy metabolism in Saccharomyces cerevisiae

A chemostat culture technique has been developed for the growth of an unsaturated fatty acid auxotroph of Saccharomyces cerevisiae. Any chosen steady-state cellular unsaturated fatty acid level between 75 and 15% of the total fatty acids could be established and maintained. In all cultures the steady-state glucose concentrations were maintained at levels below that which induces catabolite repression.The efficiency of oxidative phosphorylation as determined from the molar growth yield decreased as the cellular unsaturated fatty acid composition was lowered. The number of moles of ATP produced by oxidative phosphorylation per mole of glucose utilized was 7.2, 4.8, 0.7, and 0.4 for cells in which 75, 50, 44, and 34%, respectively, of the total fatty acids were unsaturated.The lesion in oxidative phosphorylation was a direct result of lowering the membrane unsaturated fatty acid composition as the respiratory activities and cytochrome content of cells and mitochondria were unaffected by a decrease in the cellular unsaturated fatty acid level from the wild-type value of about 75% down to about 34%.In cells which contained lipids with 22–28% unsaturated fatty acids, cyanide-sensitive respiration was absent, and the levels of all mitochondrial cytochromes were less than 10% of normal. The reduction in the levels of cytochromes aa₃ and b appeared to be a consequence of a loss of mitochondrial protein synthetic activity in such cells. The level of cytochrome c was also greatly decreased, indicating that the cellular unsaturated fatty acid composition was affecting either the synthesis in the cytoplasm of mitochondrial proteins or the assembly of these proteins in the mitochondria.     

Effect of light on lipid composition of Ricinus cell cultures

The changes of lipid composition were determined in callus cultures from Ricinus communis endosperm upon transfer from darkness into light. Culture in light induced chlorophyll synthesis and formation of differentiated chloroplasts. In light-grown cultures the major lipid classes were phospho- and glycolipids, dark-grown cultures were rich in triacylglycerol. The major fatty acids were linolenic acid and palmitic acid in both cultures. In the green cultures linolenic acid was predominantly esterified in glycolipids whereas in the dark-grown cultures this fatty acid was the major component of phospholipids. Ricinoleic acid was not found.Abbreviations PC phosphatidylcholine - PE phosphatidylethanolamine - MGD monogalactosyldigylceride - DGD digalactosyldiglyceride - SE steryl esters - NL neutral lipids     

A Comparative Study of CN-Resistant Respiration in Different Cultures of Tobacco Callus

The callus of Nicotiana rustica cv Gansu yellow flower and N. tabacum cv willow leaf were cultured on ordinary subculture medium (M-1) and on regeneration medium (M-2), respectively. No differentiation was observed in Gansu yellow flower tobacco callus cultures grown on both M-1 and M-2 medium. The respiration of both cultures was partially resistant to cyanide and markedly inhibited by m-chlorobenzhydroxamic acid. The relative contributions of alternative and cytochrome pathway were 31% and 47% of the total respiration, respectively, in M-1 callus cultures. The relative O₂ uptake of the two pathways was not changed significantly in M-2 callus cultures. In subcultured M-1 callus cultures of Willow leaf tobacco, the respiration mediated via alternative pathway was about 29 to 38% of the total respiration, and the cytochrome pathway still was the major respiratory pathway. In M-2 callus cultures in which differentiation occurred, the relative contribution of alternative pathway increased to 41 to 47% of the total respiration, and the cytochrome pathway decreased considerably. These results suggested that the change of respiratory electron transport pathway was probably related to the differentiation of tobacco callus cultures.     

Fatty Acid Compositions of Paracolons: Arizona, Citrobacter, and Providencia

The fatty acid compositions of stationary-phase cultures of Arizona arizonae, Citrobacter freundii, Providencia alcalifaciens, Providencia stuartii, and Providencia sp. were studied. The major fatty acids of A. arizonae, C. freundii, and Providencia were 16:0, 16:1, 17:cyclopropane, and 19:cyclopropane. The fatty acid compositions of the two strains of A. arizonae examined were similar to each other, but the three strains of C. freundii differed from one another in their fatty acid compositions. In both A. arizonae and C. freundii, the relative quantities of saturated, unsaturated, and cyclopropane fatty acids were similar to those which have been found in stationary-phase cultures of other members of the Enterobacteriaceae. The three strains of Providencia also differed from one another in their fatty acid compositions. In all three strains, the total quantity of unsaturated fatty acids was larger and that of the cyclopropane fatty acids was smaller than those found in stationary-phase cultures of other enteric bacteria.     

Lipids in plant tissue cultures. II. Unusual fatty acids in lipids of Hydnocarpus anthelminthica cultures

The lipids in callus cultures of Hydnocarpus anthelminthica were studied after 60, 160 and 460 days of growth. In each of the cultures the lipid classes usually found in plant tissue cultures were detected. With increasing age of the cultures the total lipid content as well as the proportions of triglycerides decreased. The major constituent fatty acids of the total lipids were palmitic and linoleic acids. Small amounts of cyclopentenyl fatty acids were also present. The proportions of saturated straight-chain fatty acids increased with the age of the cultures whereas the proportions of monounsaturated straight-chain fatty acids decreased. Only small changes were observed with polyunsaturated fatty acids. The content of cyclopentenyl fatty acids rose with the age of the cultures. The monounsaturated straight-chain fatty acids consisted of mixtures of isomers whose composition changed with the age of the cultures. In contrast, the polyunsaturated straight-chain fatty acids belonged exclusively to the Δ9 series, regardless of the age of the cultures.     

Changes in morphology and biochemical indices in browning callus derived from <Emphasis Type="Italic">Jatropha curcas</Emphasis> hypocotyls

Callus browning is a typical feature of callus cultures derived from the hypocotyl of Jatropha curcas. Brown callus results in decreased regenerative ability, poor growth and even death. In this study, we investigated the effect of browning on callus morphology and biochemical indices. Light microscopy and scanning electron microscopy showed striking differences in callus morphology. During browning, chlorophylls and carotenoids concentrations decreased steadily. Polyphenol oxidase (PPO) and peroxidase (POD) enzymatic activities patterns were similar during callus culture with a higher activity level at week 3 compared to week 2 or later weeks. Grey relation degree analysis indicated that PPO played a more important role than POD in enzymatic callus browning. Polyacrylamide gel electrophoresis results showed differences between browning and non-browning callus. Gas chromatography–mass spectrometry results showed that saturated and unsaturated fatty acid quantities differed significantly but there was little difference in fatty acid composition between non-browning and browning callus. Differences in 17, 18.4 and 25 kDa protein concentrations were also observed in browning and non-browning callus using sodium dodecyl sulfate–polyacrylamide gel electrophoresis.     

Fatty acids of rice coleoptiles in air and anoxia

The metabolism of lipids, like that of other components, was adversely and strongly affected when rice (Oryza sativa L.) coleoptiles were grown anaerobically. In aerobic coleoptiles, the amounts of total fatty acid, phospholipid, and total lipid per coleoptile increased by 2.5- to 3-fold between days three and seven, whereas under anoxia, the increases were all less than 60%. The total amount of lipid at day seven in anoxia was less than 30% of that in air. In air, the total fatty acid content at day three was 25 nanomoles per coleoptile and this increased to over 71 nanomoles per coleoptile at day seven. All acids except 18:0 showed substantial increases. In anoxia, the corresponding values for total fatty acids were 24 nanomoles and 27 nanomoles. The small increases were confined to the saturated fatty acids; no significant increase occurred in unsaturated fatty acids. A minor fatty acid constituent (16:1) increased from 0.09 to 1.99 nanomoles per coleoptile between days three and seven in air. This component was never observed in any fatty acid preparation from anaerobic coleoptiles. The major phospholipids under all conditions were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid. A small amount of unidentified phosphoester, not present on thin layer chromatography plates from aerobic coleoptiles, was seen in extracts of anaerobic coleoptiles. The fatty acyl substituents of each of the phospholipids were analyzed at days three and seven in coleoptiles grown aerobically and in anoxia. Each phospholipid had its own distinctive fatty acid composition which remained fairly constant under all treatments; 16:0 and 18:2 were the most abundant fatty acids in every phospholipid class. In air, the percentages of total fatty acids that were in the phospholipids were 86% on day three and 87% on day seven. In anoxia, the values at the corresponding ages were 47 and 57%. Since no net synthesis of unsaturated fatty acids occurred in anaerobic conditions, the small increase in total unsaturated acids in the phospholipids between days three and seven must have occurred at the expense of fatty acids preexisting in the neutral lipid. No unusual pathways of biosynthesis or unusual precursors are required to explain the presence of unsaturated fatty acids in the rice coleoptile. The present study and results of experiments where coleoptiles were fed [¹⁴C]acetate (BB Vartapetian et al. 1978 Plant Sci Lett 13:321-328) clearly show that unsaturated fatty acid synthesis in rice coleoptiles requires O₂, as it does in other plants.     

Induction of respiratory incompetent mutants by unsaturated fatty acid depletion in Saccharomyces cerevisiae

Constant levels of cellular unsaturated fatty acids were obtained by growing a fatty acid desaturase mutant of $\text{Saccharomyces cerevisiae}$ in glucose limited chemostat cultures supplemented with various concentrations of Tween 80. An increase in the frequency of cytoplasmic respiratory incompetent mutants was observed in cultures growing at low cellular levels of unsaturated fatty acids. This effect has been shown to result from an increase in the rate of mutation as the cellular unsaturated fatty acid level is decreased. The majority of induced petite mutants are ?° (contain no mitochondrial DNA).     

Effect of alternating magnetic field on the composition and level of lipids in radish seedlings

The effects of alternating magnetic field (AMF) with the frequency of 50 Hz on the dynamics of unfolding of cotyledon leaves, the composition and level of polar and neutral lipids and their component fatty acids (FA) were studied in 5-day-old radish seedlings (Raphanus sativus L. var. radicula D.L., cv. Rozovo-krasnyi s belym konchikom) grown in the light and in the dark. AMF weakened the inhibitory effect of light on unfolding of cotyledon leaves. In the light, the total content of lipids, as well as the level of polar and neutral lipids, in the seedlings in AMF was greater than in control material. In polar lipids, the total amount of glyco-and phospholipids increased; in neutral lipids, the level of triacylglycerols rose. The ratio between phospholipids and sterols (PhL/S) increased. In the dark, the total content of lipids and the level of neutral lipids in the seedlings in AMF were lower than in control material, and the ratio PhL/S decreased. In control material, there were no differences in the relative total content of unsaturated FA in the light and in the dark, whereas the level of linolenic acid was higher in the light than in the dark. AMF induced a decrease in the content of linolenic acid in the light and a rise in the dark; the level of erucic acid in the light decreased. The ratio between unsaturated and saturated FA decreased both in the light and in the dark. It was concluded that AMF with the frequency of 50 Hz was an adjusting agent considerably changing the content of lipids in the radish seedlings in the light and in the dark.     

In vitro culture ofBellevalia romana (L.) Rchb. I. Plant regeneration through adventitious shoots and somatic embryos

Summary Callus induction, adventitious shoot and root formation, and somatic embryogenesis were investigated in root, cotyledon and mesocotyl cultures ofBellevalia romana (L.) Rchb. grown on a synthetic nutrient medium containing different plant hormones. The combination of naphtaleneacetic acid plus benzylaminopurine was very effective in causing callus growth and plant regeneration from mesocotyl explants. On the contrary 2,4-dichlorophenoxyacetic acid caused suppression of shoot bud development in the same type of callus. Both cotyledon and root derived calli showed a low growth rate and did not regenerate shoots but only roots. Differentiation of somatic embryos which eventually developed into plantlets was promoted by 2,4-dichlorophenoxyacetic acid in suspension cultures. The results are discussed in relation to studies on nuclear behaviour during different morphogenetic pathways.     

Somatic embryogenesis from callus cultures of <Emphasis Type="Italic">Terminalia chebula</Emphasis> Retz.: an important medicinal tree

Somatic embryogenesis was obtained from cotyledon and mature zygotic embryo callus cultures of Terminalia chebula Retz. Callus cultures of cotyledon and mature zygotic embryo were initiated on induction medium containing Murashige and Skoog (MS) nutrients with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) either 0.01 or 0.1 mg/l Kinetin and 30 g/l sucrose. Induction of somatic embryogenesis, proliferation and development was obtained through different culture passages. Embryogenic cotyledon callus with globular somatic embryos was obtained on MS basal medium supplemented with 50 g/l sucrose. Globular somatic embryos were observed from mature zygotic embryo callus on induction medium. Different stages of somatic embryo development from cotyledon and mature zygotic embryo calluses were observed on MS basal medium supplemented with 50 g/l sucrose after 4 weeks of culture. Histological studies have revealed the developmental stages of somatic embryos. A maximum of 40.3±1.45 cotyledonary somatic embryos/callus was obtained from mature zygotic embryo compared to 7.70±0.37 cotyledonary somatic embryos/callus initiated from cotyledons. Germination of somatic embryos and conversion to plants were achieved. Highest frequency of germination (46.66±0.88) of somatic embryos was obtained on MS basal medium containing benzyladenine (0.5 mg/l) with 30 g/l sucrose.     

Changes in fatty acid distribution and thermotropic properties of phospholipids following phosphatidylcholine depletion in a choline-requiring mutant of Neurospora crassa

Growth of a choline requiring auxotroph of Neurospora crassa on medium lacking exogenous choline produces large changes in the levels of phosphatidylethanolamine and phosphatidylcholine. Whole cell fatty acid distributions were found to vary widely between different phospholipid species of normally growing, choline-supplemented cultures with phosphatidylcholine showing the highest levels of unsaturation and anionic phospholipids and cardiolipin having the lowest. In these lipids, choline deprivation produced little change in fatty acid profiles of phosphatidylethanolamine, whereas changes in fatty acids of phosphatidylcholine and acidic phospholipids resulted in increased levels of unsaturation at both growth temperatures. Microsomal phospholipids also showed fatty acid variability with sharp decreases in phosphatidylcholine unsaturates and increases in acidic phospholipid unsaturated fatty acids at low growth temperatures. Fluorescence polarization of 1,6-diphenylhexatriene in vesicles formed from total cellular and microsomal lipids showed that choline deprivation produces changes in thermotropic properties in the lipids in deprived cultures at either growth temperature. The effective differences in fluorescence polarization between choline-deprived and supplemented cultures grown at a given temperature were found to be comparable to those produced by temperature acclimation in normally growing cultures over a temperature range of 22 K.     

银杏胚的培养及不定芽的产生

通过对银杏未成熟胚和近成熟胚的培养,研究其不定芽的发生情况.结果表明:(1)银杏的种胚存在生理后熟现象,10月上旬,胚未成熟,在360个种核中,小子叶胚数(1.0～3.0 mm)为26.1％,大子叶胚(3.0～5.0 mm)的种子数占总种核数的42.2％,种核的出胚率为71.1％;(2)大子叶胚和小子叶胚接种在不同的培...     

Chloroplast number in guard cells as ploidy indicator of in vitro-grown androgenic pepper plantlets

Protoplasts were isolated from field and in vitro-grown leaves, cotyledons and cell suspension cultures (of ovule callus origin) of the scion apple cultivars Starkrimson, Rainier, Qiujin and Liaofu. Fast-growing calluses were obtained from leaf, cotyledon and cell suspension derived protoplasts of the four genotypes. The best proliferation responses were obtained from cell suspension protoplasts. For all genotypes tested, nodular calluses were obtained from protoplasts that had originally been cultured on K8P medium, but only those of cultivar Starkrimson underwent organogenesis. In this cultivar shoot buds were produced on callus derived from both cotyledon and cell suspension protoplasts and complete plants. This is the first example of whole plant regeneration from protoplasts isolated from an undifferentiated tissue in apple.Abbreviations BA 6-benzylaminopurine - 2,4-d 2,4-dichlorophenoxyacetic acid - IAA 3-indole acetic acid - IBA 3-indole butyric acid - LH lactalbumin hydrolysate - MS Murashige & Skoog (1962) - NAA 1-naphthaleneacetic acid - TDZ thidiazuron - VC L(+) ascorbic acid