Differences between bacterial associations with two root types of Vicia faba L

Abstract

Differences between various inherent physiological characteristics of lateral roots and of taproots of faba bean plants (Vicia faba L.) have been described in the literature. The question as to whether distinct bacterial communities inhabit each of those root types calls for further investigation. This question was tackled using aeroponically grown plants, i.e., plants that were grown under conditions as homogeneous as possible. Samples of the apical 5 cm of taproots and of lateral roots were compared. Metabolic fingerprints of root bacterial communities were analyzed using the Biolog® assay. Specificity of colonization of the different root types by specific bacterial taxa was examined by the Real-Time Polymerase Chain Reaction (PCR) method. Root bacterial communities produced distinct metabolic fingerprints for each of the two root types. Herbaspirillum spp. were found to be associated with lateral roots but not with taproots both under non-saline and saline (50 mM NaCl) conditions. No significant differences were found in the abundance of bacteria with respect to either root type or salinity. It is concluded that different root types, even within single root systems, differ not only in their physiological traits but also in their bacterial associations. Such associations might have adaptive advantages.     

Lipids in hairy roots and non-Agrobacterium induced roots of Crambe abyssinica

Hairy root cultures of Crambe abyssinica were obtained through infection of leaves with two wild-type agropine strains of Agrobacterium rhizogenes. The efficiency of transformation was about 16 %. The presence of T-DNA from A. rhizogenes in the hairy roots genome was confirmed by PCR using specific primers for rolB and rolC genes. Selected clones of hairy roots and non-Agrobacterium induced roots from sterile cultures were used for analyses of acyl-lipids. The total amount of acyl-lipids per mg of dry weight was similar in both the non-Agrobacterium induced roots and the hairy roots in good physiological condition, and ranged from 38 to 53 nmol. However, in the clones which showed symptoms of ageing, the lipid content was severely reduced. Also the lipid composition of hairy roots appears to be similar to the composition of non-transformed roots. Polar lipids were the dominant class of lipids in both types of roots (about 75 %). Furthermore, we found diacylglycerols, free fatty acids (FFA), triacylglycerols, sterol esters, and an unidentified lipid class. The dominant fatty acids in the lipids of both types of roots were α-linolenic acid, palmitic acid, and linoleic acid (over 12 % of total FA). Among the lipids of both hairy roots and non-Agrobacterium induced roots of C. abyssinica, an unidentified FA was found (over 16 % of total FAs). The present study is the first example of establishment of hairy roots cultures of C. abyssinica. It also includes the first analysis of the lipids in hairy roots and non-Agrobacterium induced roots of this species.     

Lipid Composition of Citrus Leaves from Plants Resistant and Susceptible to Citrus Bacterial Canker

The contents and composition of lipids in citrus leaves in relation to their general resistance to infection by strains of Xanthomonas campestris pv. citri (Xcc) were determined. The composition and contents of total polar lipids and phospholipids and the degree of fatty acid unsaturation were significantly different between resistant and susceptible species. Leaves from resistant plants had less phospholipids, but more free sterols than those from susceptible plants. The predominant fatty acids in the phospholipids were palmitic (16:0), linoleic (18:2) and α-linolenic acid (18:3). The degree of fatty acid unsaturation was higher in susceptible plants than in resistant plants. Major phospholipids in citrus leaves were phosphatidylchloline (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylinositol (PI). β-Sitosterol, campesterol and lanosterol were major sterols in the leaves of citrus plants with resistant species having a higher ratio of free sterols to total phospholipids than susceptible species. Differences in lipid metabolism may contribute to differences in Xcc-resistance of citrus leaves.     

Effect of Choline Chloride on the Lipid Content and Composition in the Leaves of Principal Magnetically-Oriented Radish Types

The effects of radish seed treatment with choline chloride on the number and weight of leaves, the weight of roots, as well as the content and composition of polar and neutral lipids and their component fatty acids in the leaves of principal magnetically-oriented types (MOTs) of radish (cv. Rosovo-krasnyi s belym konchikom), that is, North–South (NS) and West–East (WE) ones, were investigated. It was shown that seed treatment with 1% choline chloride increased the proportion of WE MOT in plant population. In spring and in autumn, this treatment increased the weight of roots of the NS MOT plants, but did not affect this index in the WE MOT plants. In the spring NS MOT plants, choline chloride treatment did not change the absolute content of polar lipids as compared to the control, but in autumn, this index increased. Meanwhile, in the WE MOT plants, it increased in spring and did not change in autumn. In the spring NS MOT plants, the content of neutral lipids increased, but in the autumn plants, it did not change. At the same time, in the WE MOT plants, this index decreased both in spring and in autumn. Seed treatment with choline chloride resulted in a substantial increase in the total content of phospholipids, in particular, that of phosphatidylcholine and phosphatidylethanolamine, in the NS and WE MOT plants sampled both in spring and in autumn. In addition, the ratio of unsaturated to saturated fatty acids, as well as that of linolenic to linoleic fatty acids, somewhat increased in the NS MOT leaf lipids, but decreased in the WE MOT ones. Presowing treatment of radish seeds with choline chloride variously and sometimes oppositely affected the content and composition in the NS and WE MOT leaf lipids. This seems to be caused by different response of these MOTs to the environmental factors.     

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.     

Changes of lipid composition in non-cultured and cultured porcine embryos

The objective of the present study was to evaluate the lipid composition of cultured and non-cultured pig embryos during cleavage using histochemical methods. The authors studied pig zygotes as well as 2-to 4-cell embryos, morulae, and blastocysts that were either non-cultured or cultured in NCSU-23 medium. To detect different types of lipids, the authors used the Churukian method with Oil red O, the Sudan black B method, the Cain method with Nile blue sulfate, and the modified osmium tetroxide-ethanol treatment. In the zygotic lipid droplets, diverse classes of unsaturated and saturated lipids were found, with particularly high levels of unsaturated hydrophobic lipids, mainly triglycerides and other esters, free fatty acids, and phospholipids. In the zygotic cytoplasm, the authors observed high levels of fatty acids and phospholipids. The total lipid content remained constant up to the morula stage, decreasing later at the blastocyst stage, but the overall amount of unsaturated lipids declined earlier, at the 2-to 4-cell stage. The amount of free fatty acids and phospholipids decreased during cleavage in both non-cultured and cultured porcine embryos. The main differences between the non-cultured and cultured embryos were the more pronounced reduction in the amount of unsaturated hydrophobic lipids in droplets and the cytoplasmic free fatty acids observed in the cultured morula and the lower content of phospholipids in the cytoplasm of the cultured 2-to 4-cell embryos relative to the non-cultured embryos. The decrease in the unsaturated lipid, free fatty acid, and phospholipid content during in vivo development and the differences in the amount of these types of lipids between developmentally matched cultured and non-cultured pig embryos correlate well with modifications of lipid and carbohydrate metabolism.     

Modification of the fatty acid composition of individual phospholipids and neutral lipids after infection of the simian erythrocyte by Plasmodium knowlesi

Using capillary gas-liquid chromatography, we have analyzed the alteration in the total fatty acid, phospholipid and neutral lipid compositions of the monkey erythrocyte, after infection by the malarial parasite Plasmodium knowlesi. Data based on fatty acid quantitation show that the phospholipid composition is altered, with particularly large increases in phosphatidylcholine (PC) and phosphatidylethanolamine (PE), the most abundant phospholipids in normal and P. knowlesi-schizont-infected cells. Unesterified fatty acids were found to be less abundant in infected cells. The total fatty acid content of the cell is increased 6-fold during infection, and total fatty acid composition is also changed: the infected cells are richer in palmitate (+23%), oleate (+29%) and linoleate (+89%), but contained less stearate (-27%) and arachidonate (-40%). The determination of the fatty acid composition of individual phospholipids, neutral lipids and unesterified fatty acids showed that choline-containing phospholipids (PC and sphingomyelin) were not as altered in their fatty acid pattern as anionic phospholipids (PE, phosphatidylserine (PS) and phosphatidylinositol (PI) and lysophosphatidylcholine (lysoPC). Specific alterations in the fatty acid compositions of individual phospholipids were detected, whereas the rise in linoleic acid was the only change during infection that was recovered in each phospholipid (except PC), neutral lipid and unesterified fatty acids. The fatty acid composition of the neutral lipids and unesterified fatty acids was particularly modified: the only rise in arachidonic acid level was observed in these lipid classes after infection. The total plasmalogen level of the erythrocyte is decreased in infected cells (-60%), but their level is increased in PI.     

Aluminum mediates compositional alterations of polar lipid classes in maize seedlings

Changes in lipid composition were investigated on maize roots and shoots under aluminum stress. After 4d exposure to 100 microM Al, root growth was inhibited while shoot growth was not affected. In roots, the decrease of the DBI (double bond index) of total fatty acids may signal a decrease in membrane fluidity. The total lipids (TL) decreased by 49%, but phospholipids (PL), phosphatidylcholine (PC) and phosphatidylinositol (PI) increased to approximately 3-fold. The MGDG increased to 2-fold but no significant change was found in the DGDG. The steryl lipids (SL) increased by 69%. The SL/PL ratio decreased from 2.64 to 1.52 and the MGDG/DGDG ratio increased from 0.45 to 1.06 in roots of Al-stressed plants. Al leads to oxidative stress in roots of treated plants as indicated by the increase of malondialdehyde (MDA) concentrations. In shoots, changes in fatty acid composition were associated with an increase of the DBI in all lipid classes except that of the DGDG decreased. The PG was the lipid class which shows the large variation of fatty acid composition. No significant changes were found either for TL, PL, SL or MDA concentrations in shoots of Al-treated plants. While PE levels did not show significant change, PI and PG increased and PC decreased. However, the Al caused 87% decrease in the GL levels. The MGDG and DGDG decreased to 19- and 8-fold, respectively. The deleterious effects of Al on polar lipids could be caused by a direct intervention of Al on plasma membrane and/or alteration of cell metabolism.     

Lipids,amino acids,sugars, hardiness and growth of Festuca arundinacea

Tall fescue (Festuca arundinacea Schreb. cv S.170) plants were grown in environments differing only in temperature: 6/4, 16/14 or 21/19°. The content of total and individual sugars and amino acids in leaf laminae and roots did not relate closely to the hardiness of the organ. The unsaturation of lipid fatty acids alone was clearly unrelated to hardiness because the difference in unsaturation was greater in the neutral lipids, glycolipids and phospholipids from roots than from leaves but only the latter differed in hardiness. Total amounts of lipids could have been related to hardiness but phospholipids and glycolipids in the roots were not. At least some of these changes may be related to adaptation of growth to temperature.     

Seasonal composition of lipids, fatty acids, and sterols in the edible red alga Grateloupia turuturu

Composition of lipids, sterols, fatty acids (FA), and phospholipids in the edible Rhodophyta Grateloupia turuturu from Britanny, France, was investigated over four seasons in order to identify compounds with potential benefits in health and nutrition. The lipid content was found to vary from 3.3 to 4.1 % dry weight. No marked variations were observed for glycolipids accounting for 42.3–46.8 %, whereas neutral lipids and phospholipids fluctuated from 20.1 % (summer) to 41.8 % (winter), and 11.2 % (winter) to 33.4 % (summer), respectively. Polyunsaturated FA of the total lipids were found from 20.4 % (winter) to 31.1 % (summer), including 20:5 ω3 acid as the major one (up to 16.3 % in summer). Phosphatidylcholine (20.0–43.7 %) and phosphatidylserine (24.6–37.5 %) were the dominant phospholipids in all seasons. Compounds of interest were identified in minor amounts such as squalene, α-tocopherol, phytonadione (vitamin K₁), cholesteryl formate, cholest-4-en-3-one, and cholesta-4,6-dien-3-one. Cholesterol was the major sterol with a lower content in spring and summer.     

Fatty acid composition and incorporation of arachidonic acid into phospholipids of hemocytes from the tobacco hornworm Manduca sexta

The fatty acid compositions were determined for total lipids, triacylglycerols, phospholipids and four phospholipid fractions, including phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine/phosphatidylinositol (PS/PI) and cardiolipin (CA) obtained from hemocytes and cell-free serum from second day, fifth instar larvae of the tobacco hornworm Manduca sexta and the standard Manduca rearing medium. The hemocyte fatty acid profiles were considerably different from the profiles of the medium the insects were reared on and from the profiles of the cell-free serum. Hemocyte neutral lipids had lower proportions of polyunsaturated fatty acids than phospholipids. The fatty acid profiles of PC, PE, PS/PI and CA differ from each other and from the total lipid profiles, indicating selective fatty acid incorporation into hemocyte phospholipid species. Studies with radioactive arachidonic acid similarly indicated selective incorporation of polyunsaturated fatty acids into hemocyte lipids. Under our in vitro conditions, >40% of the total radioactivity was incorporated into hemocyte lipids. About 93% of the incorporated radioactivity was found in phospholipids. Within phospholipids. most of the radioactivity was associated with PC (46%), and less with PE (28%) and PS/PI (21%). Very little radioactivity was recovered in CA (0.9%).     

Effect of paclobutrazol on membrane lipids in apple seedlings

The effect of paclobutrazol [( 2RS, 3RS )-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2, 4-triazol-1-yl) pentan-3-ol] on the fatty acid composition of polar lipids and on the sterol content in apple ( Malus domestica Borkh. cv. York Imperial) seedlings was determined. Polar lipids isolated from leaves, stems and roots included mono- and digalactosyldiglycerides and the phospholipids phosphatidylinositol, phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The predominant fatty acids in membrane polar lipids were palmitic (C16:0), linolnic (C18:2) and linolenic (C18:3). The predominant sterol, both free and esterified, was β-sitosterol. There were no significant alterations in the fatty-acid composition of glyco- and phospholipids from paclobutrazol-treated apple seedlings. In contrast, a significant decrease in the content of β-sitosterol and campesterol occurred in treated tissues. The decline in sterol content continued with increasing duration of paclobutrazol treatment, and was most pronounced in the root tissue.     

Fatty Acid Distribution in Glycolipids and Phospholipids in Cotyledons of Germinating Soybeans

This investigation was conducted to observe changes in the fatty acid distributions of glycolipids (GL) and phospholipids (PL) in cotyledons of soybean seeds which were germinated either in the dark or the light at 28°C for 8 days. The GL isolated from the total lipids of cotyledons at different germinating stages were : acyl sterylglycoside (ASG), monogalactosyl diglyceride (MGD), digalactosyl diglyceride (DGD) and sulfolipid (SL). The PL isolated from the same total lipids as described above were : diphosphatidyl glycerol (DPG), phosphatidic acid (PA), phosphatidyl ethanolamine (PE), phosphatidyl glycerol (PG), phosphatidyl choline (PC) and phosphatidyl inositol (PI).

During germination of soybean seeds, the content of linoleic and linolenic acids in MGD or DGD was markedly higher than that of the other GL. The positional distribution of fatty acids in PE, PC and PI was shown in all PL, in which saturated fatty acids, especially palmitic acid, were highly concentrated in position 1 and unsaturated fatty acids, especially linoleic acid, mainly occupied position 2. A remarkable difference in the changing patterns of fatty acid composition, which depended on the germinating conditions tested, was observed between GL and PL. The changes in fatty acid composition of GL were more marked in the light-grown seedlings than in the dark-grown, whereas those of PL were more remarkable in the latter than in the former. Therefore, the positional distribution of fatty acids in PL was more evident in the light-grown seedlings than in the dark-grown ones.

These results suggest the metabolic fate of GL and PL in cotyledons of soybean seeds, probably owing to the differences in the two germinating conditions tested.     

Changes of Blue Mussels Mytilus edulis L. Lipid Composition Under Cadmium and Copper Toxic Effect

The lipid and fatty acid composition of the blue mussels Mytilus edulis L. gills and digestive glands was evaluated after 24 and 72 h of cadmium (Cd) and copper (Cu) exposure. Mussels were exposed to different cadmium (10, 100, and 500 μg/L) and copper (5, 50, and 250 μg/L) concentrations. Similar stress response of predominant membrane phospholipids level as well as polyenoic and non-methylene interrupted (NMI) fatty acids content was observed in mussel gills under both cadmium and copper effects. Increased NMI fatty acids level after 24 h, the metal ions treatment suggests that these acids contribute to the protective response to the membrane oxidative stress caused by accumulation of the metals. The content of cholesterol, some minor membrane phospholipids, and storage lipids (triacylglycerols, TAG) in the mussels’ organs alter significantly under the cadmium and copper effect. A two-step response at the digestive glands TAG level depends on the duration of the cadmium and copper treatments (24 and 72 h) on the mussels. The results demonstrate that Cd and Cu impact has adverse effects on gills and digestive glands lipid and fatty acids composition. The type of observed effects varies with the nature and concentration of the metal ions and depends on the role of the metals in the mussels’ life activity.     

水分逆境对吊兰叶片脂质组成的影响

测定了吊兰（ Ｃｈｌｏｒｏｐｈｙｔｕｍ ｃｏｍｏｓｕｍ） 在干旱、正常浇水和渍水三种供水条件下叶片的磷脂组成、膜脂和总磷脂的脂肪酸组成,以及磷脂中４ 种主要组分ＰＧ、ＰＥ、ＰＣ 和ＰＩ的脂肪酸组成,观察到干旱使磷脂中ＰＥ 的相对含量增加,ＰＥ 脂肪酸中１６ ：０ 明显减少,而膜脂、总磷脂和ＰＣ、ＰＩ中饱和脂肪酸增加,但ＰＧ脂肪酸组成变化很小     

水分逆境对吊兰叶片膜质组成的影响

测定了吊兰(Chlorophytum comosum)在干旱、正常浇水和渍水三种供水条件下叶片的磷脂组成、膜脂和总磷脂的脂肪酸组成,以及磷脂中4种主要组分PG、PE、PC和PI的脂肪酸组成,观察到干旱使磷脂中PE的相对含量增加,PE脂肪酸中16:0明显减少,而膜脂,总磷脂和PC、PI中饱和脂肪酸增加,但PG脂肪酸组成变化很小。     

Effect of cadmium on lipid composition of pepper

Seedlings (2 weeks old) of pepper (Capsicum annum) were grown in nutrient solution with added CdCl(2) (10 or 50 microM) for 7 days. In Cd-treated plants, changes in acyl lipids and fatty acid composition were investigated. Cd particularly lowered the amount of monogalactosyldiacylglycerol (MGDG) and enhanced accumulation of phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine and phosphatidylglycerol] in leaves. In contrast, content of PC and galactolipids (MGDG and digalactosyldiacylglycerol) decreased in roots. Fatty acid composition of leaves was also changed by Cd addition to external medium, but no important changes occurred in roots. Levels of leaf polyunsaturated fatty acids, especially 18:3 and 16:3, were reduced. Lipid and fatty acid composition changes in roots are discussed in relation to Cd tolerance in pepper.     

Effects of Cadmium on Polar Lipid Composition and Unsaturation in Maize （Zea mays） in Hydroponic Culture

This study aimed to evaluate the effect of Cd exposure （100 μmol/L） on polar lipid composition, and to examine the level of fatty acid unsaturation in maize （Zea mays L.）. In roots, the level of 16：0 and monounsaturated fatty acids （16：1 ＋ 18：1） decreased in phosphatidylcholine （PC） and phosphatidylethanolamine （PE）. In contrast, the proportion of unsaturated 18-C fatty acid species showed an opposite response to Cd. The content, on the other hand, of PC, PE, digalactosyldiacylglycerol （DGDG）, and steryl lipids increased in roots （2.9-, 1.6-, 5.3-, and 1.7-fold increase, respectively）. These results suggest that a more unsaturated fatty acid composition than found in control plants with a concomitant increase in polar lipids may favor seedling growth during Cd exposure. However, the observed increase in the steryl lipid （SL） ： phospholipid （PL） ratio （twofold）, the decrease in monogalactosyldiacylglycerol （MGDG） ： DGDG ratio, as well as the induction of lipid peroxidation in roots may represent symptoms of membrane injury. In shoots, the unsaturation level was markedly decreased in PC and phosphatidylglycerol （PG） after Cd exposure, but showed a significant increase in sulfoquinovosyldiacylglycerol （SQDG）, MGDG and DGDG. The content of PG and MGDG was decreased by about 65%, while PC accumulated to higher levels （4.4-fold increase）. Taken together, these changes in the polar lipid unsaturation and composition are likely to be due to alterations in the glycerolipid pathway. These results also support the idea that the increase in overall unsaturation plays some role in enabling the plant to withstand the metal exposure.     

Lipids and fatty acids of the southwestern corn borer,Diatraea grandiosella

The lipids of the adults and of several immature stages of the southwestern corn borer, Diatraea grandiosella, were studied after they were fed natural corn stalks or artificial diets. Linoleic acid (18:2) was the major fatty acid of the neutral lipids in both the natural and the artificial diets, but aleic acid (18:1) was the principal neutral lipid in all insect stages. Also, linoleic acid and oleic acid were the principal acids in the insect phospholipids of all stages. The content of linoleic acid in the natural diet was also high, but that in the artificial diet appeared to be much too low for insect requirements. Phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) were the major phospholipids in all growth stages. Thus, in larvae diapausing in the field, the unsaturated fatty acid content of PC was 59·3 per cent, primarily 16:1 and 18:1, and PE was 87·4 per cent, primarily 18:1, 18:2, and 18:3, and the fatty acids in the number 1- and 2-positions of PC were 53·6 and 97·2 per cent unsaturated, respectively. The haemolymph of diapausing southwestern corn borer larvae contained primarily glycerides but also had some PC and PE. Fat body from diapausing larvae contained primarily 16:0, 16:1, and 18:1 in a ratio of 1 : 1 : 2. Thus lipids of the southwestern corn borer do not reflect dietary lipids as closely as do other insects studied.     

Phospholipid Composition and Metabolism of Micrococcus denitrificans

The phospholipid composition of Micrococcus denitrificans was unusual in that phosphatidyl choline (PC) was a major phospholipid (30.9%). Other phospholipids were phosphatidyl glycerol (PG, 52.4%), phosphatidyl ethanolamine (PE, 5.8%), an unknown phospholipid (5.3%), cardiolipin (CL, 3.2%), phosphatidyl dimethylethanolamine (PDME, 0.9%), phosphatidyl monomethylethanolamine (PMME, 0.6%), phosphatidyl serine (PS, 0.5%), and phosphatidic acid (0.4%). Kinetics of ³²P incorporation suggested that PC was formed by the successive methylations of PE. Pulse-chase experiments with pulses of ³²P or acetate-1-¹⁴C to exponentially growing cells showed loss of isotopes from PMME, PDME, PS, and CL with biphasic kinetics suggesting the same type of multiple pools of these lipids as proposed in other bacteria. The major phospholipids, PC, PG, and PE, were metabolically stable under these conditions. The fatty acids isolated from the complex lipids were also unusual in being a simple mixture of seven fatty acids with oleic acid representing 86% of the total. Few free fatty acids and no non-extractable fatty acids associated with the cell wall or membrane were found.