Search

The objective was to verify vigor tests efficiency in the evaluation the crambe seeds physiological quality. Four lots of crambe seeds of cultivar 'FMS Brilhante' were submitted to the following standard germination and vigour test (first germination count, length and dry mass of seedling, seedling emergence in sand and field, electrical conductivity, accelerated ageing and controlled deterioration). The experiment was conducted in a randomized complete block design for test, evaluating the lots effect. The seedling emergence in field test and the controlled deterioration test at pre-moistened seeds at 15% and maintained under 42°C/48h and at 25% under 45°C/36h are efficients classifying the crambe seeds lots in different vigour levels. [ABSTRACT FROM AUTHOR]

The aim of this work was to evaluate the effects of variation in nitrate (NO3−-N) supply on nitrogen (N), phosphorus (P), and potassium (K) values and several aspects of N metabolism in crambe (Crambe abyssinica). Crambe plants were submitted to crescent NO3−-N doses (1.0; 2.5; 5.0 and 7.5 mM) under hydroponic culture in greenhouse and, at the end of vegetative stage (68 days after germination) harvest was performed. Increase in NO3−-N supply caused a significant growth of it levels in stem, suggesting that this organ acts as a preferential storage site of this anion in crambe. Low P and high K values were observed in plants under 1.0 mM NO3−-N. Whereas, with 7.5 mM was verified a decrease in NO3−-N reductase activity and low N levels. At this dose, plants also exhibit other evidences of suppression in NO3−-N reduction such as high amino-N levels. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the efficacy of using crambe seeds byproduct as biosorbent in the removal of chromium heavy metal from contaminated solutions. By means of scanning electron microscopy, infrared spectroscopy and the determination of the point of zero charge was performed the biosorbent characterization. The influence of various conditions on the ions adsorption, such as solutions at different pH conditions, variation of the biosorbent masses, contact time and temperature were investigated, and the metal concentrations determined by atomic absorption spectrometry flame mode. In trials to obtain the isotherms, the mathematical models of Freundlich and Dubinin-Radushkevich best fitted the experimental data. The desorption study demonstrated intense interaction between the metal and adsorbent, which confirms the data from the pseudosecond order model and mean energy of Dubinin-Radushkevich model for chemiosorption. The maximum adsorption capacity of biosorbent was estimated at 6.807 mg.g-1. To comparative study with a commercial adsorbent, activated carbon was used for tests of adsorption and desorption. Based on these results, it was concluded that the byproduct was effective in removing chromium from aqueous solutions, and its use as a viable alternative material for this metal removal, in addition to being a byproduct, which has not suffered pretreatment. [ABSTRACT FROM AUTHOR]

This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30 % oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C and C carbon glycerol, sterols, tocopherols, peroxide value, $$ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $$ at 232 nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77 %). The dominant saturated acid was C22:0 (2.14 %). The oil was also found to contain high levels of β-sitosterol (51.93 %), campestanol (21.98 %), and brassicasterol (12.35 %). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99 mg/kg, respectively. The induction period (at 110 °C and 20 l/h) of the oil was 8.83 h. The relative position of fatty acids in C and C position was as follows: linoleic 0.45 %, oleic 8.84 %, and erucic 90.72 %. The thermal profile of the oil presented a single peak at −20.94 °C. [ABSTRACT FROM AUTHOR]

Abstract: In the present work liquid–liquid equilibrium (LLE) data were obtained for systems composed of glycerol+ethanol+distilled fatty acid ethyl esters from crambe oil at T/K=298.2, 318.2 and 338.2. The experimental data measured for these systems were used to adjust the binary interaction parameters between their components for NRTL model treating the mixture of ester as a single ethyl ester, with the average molar mass of the mixture of esters. Two sets of UNIFAC binary interaction parameters were also tested to predict the LLE of the systems. Ethanol, which is distributed in the glycerol-rich and ester-rich phases, showed a greater affinity to the glycerol rich phase. Glycerol and FAEE presented very low miscibility. The average deviations related to mass fraction composition between experimental and calculated values by the NRTL model were less than 0.82% and by the UNIFAC model were between 2.27% and 3.97%, considering the two different sets of binary interaction parameters. [Copyright &y& Elsevier]

Erucic acid (22 : 1) is a major feedstock for the oleochemical industry. In this study, a gene stacking strategy was employed to develop transgenic Crambe abyssinica lines with increased 22 : 1 levels. Through integration of the LdLPAAT, BnFAE1 and CaFAD2-RNAi genes into the crambe genome, confirmed by Southern blot and qRT-PCR, the average levels of 18 : 1, 18 : 2 and 18 : 3 were markedly decreased and that of 22 : 1 was increased from 60% in the wild type to 73% in the best transgenic line of T4 generation. In single seeds of the same line, the 22 : 1 level could reach 76.9%, an increase of 28.0% over the wild type. The trierucin amount was positively correlated to 22 : 1 in the transgenic lines. Unlike high erucic rapeseed, the wild-type crambe contains 22 : 1 in the seed phosphatidylcholine and in the sn-2 position of triacylglycerols (5% and 8%, respectively). The transgenic line with high 22 : 1 had decreased 22 : 1 level in phosphatidylcholine, and this was negatively correlated with the 22 : 1 level at the sn-2 position of TAG. The significances of this study include (i) achieving an unprecedented level of 22 : 1 in an oil crop; (ii) disclosing mechanisms in the channelling of a triacylglycerol-specific unusual fatty acid in oil seeds; (iii) indicating potential limiting factors involved in the erucic acid biosynthesis and paving the way for further increase of this acid and (iv) development of an added value genetically modified oil crop having no risk of gene flow into feed and food crops. [ABSTRACT FROM AUTHOR]

Abstract: Crambe abyssinica is a fast growing non-food high biomass crop with significant potential for biofuel production and for phytoremediation of heavy metal contaminated soils and sediments. We have developed an efficient Agrobacterium-mediated transformation system for C. abyssinica ‘BelAnn’ using β-glucuronidase (gus), bacterial arsenate reductase (ArsC), and γ-glutamylcysteine synthetase (γ-ECS) genes. Pre-cultured hypocotyl explants were infected with Agrobacterium tumefaciens strain LBA4404 harboring binary vector pCAMBIA1300 containing gus, ArsC, and γ-ECS genes under the control of CaMV35S, leaf-specific SRS1p, and constitutive Act2p promoters, respectively. Following co-cultivation and selection, regenerated shoot buds were sub-cultured on MS medium containing GA3 for shoot elongation. Elongated shoots were transferred to root induction medium for 1 week. Semi-quantitative RT-PCR analysis confirmed the expression of mRNA transcripts for gus, ArsC and γ-ECS genes in T0 generation transgenic plants. Histochemical assays showed the gus expression in both vegetative and reproductive tissues of stably transformed T1 generation plants. Germinating seeds from T1 transgenic plants grown on MS medium containing hygromycin revealed a 3:1 Mendelian inheritance pattern for each transgene. Immunoblotting assays further confirmed the stable transformation and expression of the ArsC and γ-ECS proteins in T2 generation plants using anti-ArsC and γ-ECS antibodies. This method achieved an overall frequency of 50–70% regeneration and 6.7–8.3% transformation with three different gene constructs. The method showed higher transformation efficiency than the previously reported methods and will be useful for gene manipulation in crambe to enable biomaterial and biofuel production, as well as for potential oil content modification and heavy metal phytoremediation. [Copyright &y& Elsevier]

This study was performed to evaluate the physiological quality of Crambe abyssinica Hochst fruits subjected to drying under different treatments with air. The crambe fruits, with moisture content of 21.0 ± 1.3 (% w.b.), were manually collected and dried until their moisture content reached 7.0 ± 1.4 (% w.b.). The crambe fruits were dried with natural air (23°C mean temperature and 60.6% average relative humidity) and seven days after harvest in an experimental dryer with forced ventilation at temperatures of 30, 40, 50, 60 and 70°C and relative humidities of 37.4, 22.3, 14.0, 8.3 and 5.1%, respectively. The evaluation was the percent germination, the germination speed index (GSI), the amount of water absorption and the electrical conductivity. The results of the study showed that increases in the drying temperature decreased the drying time and negatively affected the quality of the fruits. The study’s findings for the GSI and for the percent germination showed that the drying temperature of 30°C yielded superior results. The moisture content of the crambe fruits after absorption was higher at the drying temperatures of 23, 40 and 70ºC. In contrast, the electrical conductivity measurement was unaffected by drying at high temperatures. [ABSTRACT FROM AUTHOR]

The speed of the deterioration process in seeds stored under proper conditions can be reduced, and seed viability can be maintained for longer than under natural conditions. The aim of this study was to evaluate Crambe abyssinica fruit quality for storage under different environmental conditions. The initial moisture content of crambe seeds was 6% w.b. The electrical conductivity, water absorption, germination and germination speed index (GSI) were determined at the beginning (0 months) and every two months for one year. Seeds were stored under three different conditions: normal environment (26 ± 3 °C, 55 ± 12% Relative Humidity - RH), refrigerated type B.O.D. (5 ± 1 ° C, 79 ± 5% RH) and in a climate chamber with air conditioning (18 ± 1 °C, 53 ± 7% RH). The climate chamber (18 ± 1 °C, 53 ± 7% RH) maintains the best crambe fruit quality compared to the normal environment (26 ± 3 °C, 55 ± 12% RH) and the refrigerated type B.O.D. (5 ± 1 °C, 79 ± 5% RH). Fruits stored for twelve months in the three environments caused the seed dormancy to breakdown. [ABSTRACT FROM AUTHOR]

Crambe is a promising crop for biodiesel production, mainly due to the high oil content of its seeds. However, there have been no effective methodologies for evaluating the physiological quality of crambe seeds. Seed lots have not been compared, especially by vigor tests, such as the accelerated aging. The objective of this study was to evaluate the effects of high temperature and exposure periods on the physiological quality and enzymatic activity of crambe seeds during the accelerated aging test. Two lots of crambe seeds of the Brilhante cultivar were analyzed by tests of moisture content, weight of 1,000 seeds, germination, first count, electrical conductivity, enzymatic activity (peroxidase and superoxide dismutase) and seedling length. All tests were carried out before and after the accelerated aging, which evaluated different temperatures (38, 40 and 42°C) and exposure periods (24, 48 and 72 hours). The experimental design was completely randomized with four replications. Variance analysis and mean comparison through the Tukey and Dunnet tests (p ≤ 0.05) were applied for statistical analysis and means were also submitted to the linear correlation test. It was concluded that the interaction between temperature and exposure period affects the physiological quality and enzymatic activity of crambe seeds. We also conclude that the best conditions of temperature and exposure period for evaluating the physiological quality of crambe seeds through the accelerated aging test depend on genotype. [ABSTRACT FROM AUTHOR]

Chromium pollution is a serious environmental problem with few cost-effective remediation strategies available. Crambe abyssinica (a member of Brassicaseae), a non-food, fast growing high biomass crop, is an ideal candidate for phytoremediation of heavy metals contaminated soils. The present study used a PCR-Select Suppression Subtraction Hybridization approach in C. abyssinica to isolate differentially expressed genes in response to Cr exposure. A total of 72 differentially expressed subtracted cDNAs were sequenced and found to represent 43 genes. The subtracted cDNAs suggest that Cr stress significantly affects pathways related to stress/defense, ion transporters, sulfur assimilation, cell signaling, protein degradation, photosynthesis and cell metabolism. The regulation of these genes in response to Cr exposure was further confirmed by semi-quantitative RT-PCR. Characterization of these differentially expressed genes may enable the engineering of non-food, high-biomass plants, including C. abyssinica, for phytoremediation of Cr-contaminated soils and sediments. [Copyright &y& Elsevier]

This study aimed to evaluate the decomposition and nutrient release from crop residues of fodder radish and crambe in the implementation of no-tillage system. The experiment was conducted in a Distroferric Red Latossol with 762g kg-1 of clay. The experimental design was randomized blocks with four replications. The treatments were applied in split plots, considering the species of cover crops (radish and crambe) as the main plots and harvest dates of decomposition bags (0, 15, 30, 45, 60, 75 days after management) as subplots. The cover crops were treated 60 days after management, in full bloom. Radish presented a dry mass production of 5586kg ha-1 and crambe of 2688kg ha-1. The kinetics of residue decomposition had a behavior similar to the dynamics of nutrient release, with an initial rapid phase followed by a slower one. The K, P and Mg are released more quickly for subsequent crops. The increased speed of nutrients release by crops occurred around 15 days after the biomass management. [ABSTRACT FROM AUTHOR]

Water stress and seed water content can affect the first stages of germination and prejudice crop establishment. The objective of the present study was to evaluate the effect of substrate water availability and seed water content on crambe germination and to verify any harmful effects of seed imbibition. The treatments consisted of FMS Brilhante crambe seeds with 7.0%, 12.8%, 18.4% and 21.9% moisture content, submitted to substrate water availability of 0.0 (control); -0.1; -0.2 and -0.4 MPa. Seeds were sown on two germination papers and placed inside plastic boxes at a constant 25 °C. Seed physiological quality was evaluated from the first count, percentage germination, hipocotyl and primary root lengths and seedling fresh and dry weights. The experimental design was completely randomized with four replications of 50 seeds for each treatment. As substrate water availability decreased, the germinability was reduced for all seed moisture contents, especially for seeds with 7.0% and 12.8% moisture contents, resulting in less than 48% normal seedlings at -0,4 MPa. Despite a reduction in the parameters due to water deficiency, the extension of the damage in crambe seeds is determined by the seed water content and the severity of the water stress. [ABSTRACT FROM AUTHOR]

Lipids of Crambe abyssinica Hochst (Brassicaceae) seeds grown in hothouses in Israel and in the open in Uzbekistan in soil imported from the Aral Sea region were studied. It was found that the seed oil content decreased as the irrigation-water salinity increased. The content of total unsaturated fatty acids of neutral lipids was in the range 91.31-94.81%; of polar lipids, 69.59-83.78%. [ABSTRACT FROM AUTHOR]

Abstract: A highly efficient regeneration protocol for oilseed crop Crambe abyssinica has been developed using hypocotyls as explants in this study. Crambe is a potential engineering oilseed crop for industrial purposes as it contains 55–60% erucic acid in its oil and, more importantly, it does not outcross with any food oil seed crops. However, the low regeneration frequency with the currently available protocols is still a limiting factor for genetic modification of Crambe. In this study, we investigated the effects of N-source, C-source, AgNO3, cultural conditions as well as the concentration and combination of plant growth regulators (PGR) on the regeneration frequency of C. abyssinica. The results showed that all these factors, especially the N-source and PGR concentrations and combinations, played an important role in shoot regeneration. Among all the factors tested, the combination of using hypocotyls from C. abyssinica cv. galactica, the Lepiovre basal medium supplemented with 16gl−1 glucose, 0.5gl−1 AgNO3, 2.2mgl−1 thidiazuron (TDZ), 0.5mgl−1 α-naphthaleneacetic acid (NAA), 2.5gl−1 Gelrite, seeds germinated in dark for 3 days and explants cultured in light, gave the best regeneration frequency (over 95%). The results also suggest that reducing the content of NH4 + or keeping a suitable NO3 −/NH4 + ratio in the regeneration medium would be crucial to Crambe shoot regeneration. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis in Crambe abyssinica, an important industrial oilseed species, was investigated. Cotyledon, hypocotyl and root explants from 8-day-old seedlings of C. abyssinica cv. Prophet were cultured with levels of 1-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) ranging from 2.2 to 39.0 μM, combined with 6-benzyladenine (BA) to achieve an auxin:cytokinin ratio of 20:1, and callus formation assessed. Callus formation frequency for cotyledon and hypocotyl explants was 100% for levels of 2,4-D from 4.5 to 33.9 μM. The response was similar with NAA levels of 13.0 to 39.0 μM. Root explants were less responsive. When calluses were transferred to a medium containing 0.56 μM each of thidiazuron and BA with 1.0 μM indole-3-butyric acid (IBA), somatic embryos were induced. Moreover, embryos were induced from calluses grown on media containing either 11.3 μM 2,4-D or 13.0 μM NAA, or higher. On a medium without plant growth regulators, embryos were induced but at a much lower frequency. For all three explants, 22.6 μM 2,4-D and 26.0 μM NAA was optimal for embryogenic callus induction. Hypocotyl-derived calluses were superior to cotyledon- and root-derived calluses for embryo induction. The best embryo formation response was with medium containing 5.0-6.0% sucrose. The highest average number of embryos per callus (36) was obtained from hypocotyl calluses from medium with 22.6 μM 2,4-D. Somatic embryos germinated best on half-strength B5 or MS medium with 3% sucrose, and plantlets were successfully established under greenhouse conditions. The results indicate that high levels of auxins are required for the induction of embryogenic calluses from explants of C. abyssinicia, while cytokinins are critical for somatic embryo formation. [ABSTRACT FROM AUTHOR]

The aim of this research was to determine the sample size to estimate the average of the morphological and productive traits of crambe (Crambe abyssinica Hochst) and assess the relationships among these traits. An experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil (latitude 29º42'S, longitude 53º49'W and 95m altitude) in the year 2008. At harvest, 75 plants were randomly selected and measured for morphological traits (plant height, number of racemes per plant and length average of racemes per plant) and productivity (number of fruits per plant, number of fruits per raceme and grain yield). It was calculated the sample size of each trait and studied the relationship among the traits by scatter plots, correlation, path analysis and regression. In the culture of crambe, the sample size (number of plants) of productive traits is greater than morphology to estimate average and it has the same precision. The number of fruits per plant has a positive linear relationship with grain yield and can be used for indirect selection. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper was to delimitate the suitable agroclimatic area for the development of Crambe abyssinica (Hochst) in Argentina, using the biophysical limits observed in other parts of the world. To find a division into zones, the isohyet of 350mm per year, the annual average temperature of 5.7°C, the isoline corresponding to the frost free 100 days and the summer average temperature of 15°C–25°C were considered to delimit the spring crambe. To delimit the winter crambe area the same hydrological limits were used. For thermal limits the temperature of −6°C was used, with an expected returning period of once every 5 years was added, as lower temperatures would produce destruction of the crops. To delimitate the optimal zone temperatures of 8°C–14°C during spring were considered. Afterwards, maps with all the thermal and hydric limits were superposed to define the probable areas for the crop. Areas of very suitable, suitable, suitable with constrains, marginal and not suitable were identified. [Copyright &y& Elsevier]

A parameter used in the development plants models simulation development is the time interval between the appearance of two successive nodes on a stem, known as plastochron, with units of °C day node-1. The objective of this study was to estimate the plastochron in crambe (Crambe abyssinica Hochst) plants grown in two sowing dates: 18/06/08 and 12/07/08. The cultivar used was the 'FMS Brilhante', with density adjusted to 100 plants m-2. In each period 77 plants were randomly selected, and the number of nodes were counted every two days. The plastochron was estimated by the inverse slope of the linear regression between the number of accumulated nodes on the main stem and accumulated thermal time after the emergence. The crop cycle was divided into subperiods in order to assess caloric demand for each development stage. The plastochron ranged from 42.1 to 45.2°C day node-1 during the subperiod emergence to early flowering and from 28.3 to 47.8°C day node-1 during the beginning of the flowering subperiod to the onset of fruiting. Different sowing dates and development subperiods have an effect on the plastochron in crambe. The best division of the cycle is the emergence to early flowering and early flowering to the onset of fruiting to obtain reliable estimates of plastochron crambe. [ABSTRACT FROM AUTHOR]

Leaf area is important in determining the growth and development of agricultural crops. The aim of this study was to compare the methods of leaf discs and digital photos in estimating leaf area of Crambe abyssinica, and model leaf area according to length (C), width (L) and/ or the product of length width (CxL) for different sizes of leaves. For this, in 308 leaves it was determined the leaf area, length, width and the product of length width using the methods of leaf discs and digital photos. Then the methods were compared using the linear correlation coefficient between the leaf areas. Then, for each method, leaf area (Y) depending on the C, of L and the CxL, was modeled through these models: linear, simple linear, quadratic, geometric and exponential. The Pearson and Spearman linear correlation coefficient between the methods of leaf area and leaf discs of digital photos were 0.9917 and 0.9889, respectively, which shows concordant methods. In both methods, the geometric and quadratic models showed good coefficients of determination of leaf area depending on the length and width of leaves. The leaf width is the variable that best estimates the leaf area. The method of digital photos can be used to estimate Crambe's leaf area. [ABSTRACT FROM AUTHOR]

Background: Arsenic contamination is widespread throughout the world and this toxic metalloid is known to cause cancers of organs such as liver, kidney, skin, and lung in human. In spite of a recent surge in arsenic related studies, we are still far from a comprehensive understanding of arsenic uptake, detoxification, and sequestration in plants. Crambe abyssinica, commonly known as 'abyssinian mustard', is a non-food, high biomass oil seed crop that is naturally tolerant to heavy metals. Moreover, it accumulates significantly higher levels of arsenic as compared to other species of the Brassicaceae family. Thus, C. abyssinica has great potential to be utilized as an ideal inedible crop for phytoremediation of heavy metals and metalloids. However, the mechanism of arsenic metabolism in higher plants, including C. abyssinica, remains elusive. Results: To identify the differentially expressed transcripts and the pathways involved in arsenic metabolism and detoxification, C. abyssinica plants were subjected to arsenate stress and a PCR-Select Suppression Subtraction Hybridization (SSH) approach was employed. A total of 105 differentially expressed subtracted cDNAs were sequenced which were found to represent 38 genes. Those genes encode proteins functioning as antioxidants, metal transporters, reductases, enzymes involved in the protein degradation pathway, and several novel uncharacterized proteins. The transcripts corresponding to the subtracted cDNAs showed strong upregulation by arsenate stress as confirmed by the semi-quantitative RT-PCR. Conclusions: Our study revealed novel insights into the plant defense mechanisms and the regulation of genes and gene networks in response to arsenate toxicity. The differential expression of transcripts encoding glutathione-Stransferases, antioxidants, sulfur metabolism, heat-shock proteins, metal transporters, and enzymes in the ubiquitination pathway of protein degradation as well as several unknown novel proteins serve as molecular evidence for the physiological responses to arsenate stress in plants. Additionally, many of these cDNA clones showing strong upregulation due to arsenate stress could be used as valuable markers. Further characterization of these differentially expressed genes would be useful to develop novel strategies for efficient phytoremediation as well as for engineering arsenic tolerant crops with reduced arsenic translocation to the edible parts of plants. [ABSTRACT FROM AUTHOR]

Crambe (Crambe abyssinica L.) is a specialty oilseed crop. By-product crambe meal has a high glucosinolate content, restricting its use for animal feed. The purpose of this study was to evaluate crambe meal for various types of soil application. When incubated with soil, crambe meal mineralized more slowly than soybean meal, with an average of 38% of the added nitrogen (N) from crambe meal appearing as mineral N after 12 weeks of incubation, compared with 57% for soybean (Glycine max L. Merr.) meal. Sulfur mineralization from crambe meal was rapid. Bioassays indicated no phytotoxicity to seedlings from crambe meal. In a second experiment, high rates of crambe meal inhibited the nitrification of urea added to soil, but this effect was short-lived. In a third experiment, crambe meal-ferrous sulfate mixtures applied to calcareous soil partially alleviated iron deficiency chlorosis of soybean, but the response was less than observed with iron-ethylenediaminedi(o-hydroxyphenylacetic) acid. [ABSTRACT FROM AUTHOR]

The 3′-UTR of the FAD2 gene from Brassica carinata was cloned by PCR and used to prepare an intron-spliced hairpin RNA (ihpRNA) construct. Compared to that of the wild type (WT) background, this construct, when expressed in B. carinata, resulted in a high degree of FAD2 gene silencing accompanied by strong increases of up to 16 and 10% in oleic acid and erucic acid proportions, respectively. The increase in 18:1 was accompanied by a concomitant proportional reduction in 18:2. A second construct containing ihpRNA targeted to the endogenous FAD2 gene in addition to the heterologous Crambe abyssinica FAE gene under the control of seed specific napin promoter, was used to transform B. carinata. This approach resulted in an even greater increase in erucic acid proportions, by up to 16% in T1 segregating seeds as compared to that of the WT control. To our knowledge, this is currently the highest accumulation of erucic acid achieved in B. carinata seeds using transgenic approaches, making it an increasingly-attractive alternative to high erucic B. napus cultivars as an industrial oil crop. [ABSTRACT FROM AUTHOR]

Abstract: cis-Vaccenic acid or cis-11-octadecenoic acid, a C18:1 (n-7) isomer of oleic acid (C18:1 (n-9)) has been found in several oilseeds. It is synthesized from palmitic acid (C16:0) via production of C16:1 (n-7) by a Δ9 desaturase and elongation by an elongase giving C18:1 (n-7). In this study, the fatty acid composition of 12 Brassica species was analyzed by GC-FID and confirmed by GC–MS. All species contained C18:1 (n-7), C20:1 (n-7) and C22:1 (n-7) fatty acid isomers, suggesting that C18:1 (n-7) was elongated. The levels of these fatty acids varied according to the species. C18:1(n-7)) represented from 0.4% to 3.3% of the total relative fatty acid contents of the seeds. The contents of C20:1(n-7) and C22:1(n-7) levels were lower than C18:1(n-7) contents; the relative fatty acid composition varied from 0.02% to 1.3% and from below the limit of detection to 1.3% for C20:1 (n-7) and C22:1 (n-7), respectively. The ratios of (n-7)/(n-9) ranged from 2.8% to 16.7%, 0.6% to 29.5% and 0% to 2.6% for C18:1, C20:1 and C22:2, respectively. Using statistical similarities or differences of the C18:1 (n-7)/(n-9) ratios for chemotaxonomy, the surveyed species could be arranged into three groups. The first group would include Brassica napus, B. rapa, and B. tournefortii with Eruca sativa branching only related to B. napus. The second group would include B. tournefortii, Raphanus sativus and Sinapis alba. The last group would include B. juncea, B. carinata and B. nigra with no similarity/relationship between them and between the other species. Results suggested that the level of C20:1 (n-7) influenced the levels of all monounsaturated fatty acids with chain length higher than 20 carbons. On the other hand, palmitoleic acid (C16:1) levels, C16:1 being the parent of all (n-7) fatty acids, had no statistically significant correlation with the content of any of the fatty acids of the (n-7) or (n-9) family. [Copyright &y& Elsevier]

A genomic fatty acid elongation 1 ( FAE1) clone was isolated from Crambe abyssinica. The genomic clone corresponds to a 1521-bp open reading frame, which encodes a protein of 507 amino acids. In yeast cells expression of CrFAE led to production of new very long chain monounsaturated fatty acids such as eicosenoic (20 : 1Δ11) and erucic (22 : 1Δ13) acids. Seed-specific expression in Arabidopsis thaliana resulted in up to a 12-fold increase in the proportion of erucic acid. On the other hand, in transgenic high-erucic Brassica carinata plants, the proportion of erucic acid was as high as 51.9% in the best transgenic line, a net increase of 40% compared to wild type. These results indicate that the CrFAE gene encodes a condensing enzyme involved in the biosynthesis of very long-chain fatty acids utilizing monounsaturated and saturated acyl substrates, with a strong capability for improving the erucic acid content. [ABSTRACT FROM AUTHOR]

We chose crambin, a hydrophobic and water-insoluble protein originally isolated from the seeds of the plant Crambe abyssinica, as a model for NMR investigations of membrane-associated proteins. We produced isotopically labeled crambin(P22,L25) (variant of crambin containing Pro22 and Leu25) as a cleavable fusion with staphylococcal nuclease and refolded the protein by an approach that has proved successful for the production of proteins with multiple disulfide bonds. We used NMR spectroscopy to determine the three-dimensional structure of the protein in two membrane-mimetic environments: in a mixed aqueous-organic solvent (75%/25%, acetone/water) and in DPC micelles. With the sample in the mixed solvent, it was possible to determine (>NH⋯OC<) hydrogen bonds directly by the detection of h3JNC, couplings. H-bonds determined in this manner were utilized in the refinement of the NMR-derived protein structures. With the protein in DPC (dodecylphosphocholine) micelles, we used manganous ion as an aqueous paramagnetic probe to determine the surface of crambin that is shielded by the detergent. With the exception of the aqueous solvent exposed loop containing residues 20 and 21, the protein surface was protected by DPC. This suggests that the protein may be similarly embedded in physiological membranes. The strategy described here for the expression and structure determination of crambin should be applicable to structural and functional studies of membrane active toxins and small membrane proteins. [ABSTRACT FROM AUTHOR]

The ability to tolerate and accumulate arsenic (As) and cadmium (Cd) was compared between Brassica juncea (Indian mustard) and Crambe abyssinica (Hochst.) (Crambe or Abyssinian mustard). Plants were grown hydroponically and treated with 70 µM sodium arsenate or 50 µ M cadmium chloride for two weeks. When nutrients were omitted during the As treatment, leaves of C. abyssinica accumulated an average of 140 mg As kg -1 , compared with 34 mg kg -1 for B. juncea . When quarter-strength Hoagland's nutrient solution was provided during As treatment, leaves of C. abyssinica accumulated an average of 270 mg As kg -1 , compared with 13 mg kg -1 for B. juncea . Cadmium accumulation on a dry-weight basis was approximately two times greater in shoots of B. juncea . Shoot biomass production in the presence or absence of metals was greatest for C. abyssinica . Because of its larger biomass and more efficient accumulation of As, C. abyssinica should be considered for use in phytoremediation research. [ABSTRACT FROM AUTHOR]

Sexual progenies of asymmetric somatic hybrids between Brassica napus and Crambe abyssinica were analyzed with respect to chromosomal behavior, fae1 gene introgression, fertility, and fatty-acid composition of the seed. Among 24 progeny plants investigated, 11 plants had 38 chromosomes and were characterized by the occurrence of normal meiosis with 19 bivalents. The other 13 plants had more than 38 chromosomes, constituting a complete chromosomal set from B. napus plus different numbers of additional chromosomes from C. abyssinica. The chromosomes of B. napus and C. abyssinica origin could be clearly discriminated by genomic in situ hybridization (GISH) in mitotic and meiotic cells. Furthermore, meiotic GISH enabled identification of intergenomic chromatin bridges and of asynchrony between the B. napus and C. abyssinca meiotic cycles. Lagging, bridging and late disjunction of univalents derived from C. abyssinica were observed. Analysis of cleaved amplified polymorphic sequence (CAPS) markers derived from the fae1 gene showed novel patterns different from the B. napus recipient in some hybrid offspring. Most of the progeny plants had a high pollen fertility and seed set, and some contained significantly greater amounts of seed erucic acid than the B. napus parent. This study demonstrates that a part of the C. abyssinica genome can be transferred into B. napus via asymmetric hybridization and maintained in sexual progenies of the hybrids. Furthermore, it confirms that UV irradiation improves the fertility of the hybrid and of its sexual progeny via chromosomal elimination and facilitates the introgression of exotic genetic material into crop species. [ABSTRACT FROM AUTHOR]

An HF/3-21G calculation was performed for crambin, which is present in seeds of Crambe abyssinica, at the recent 0.54 A˚−1 resolution X-ray geometry. The resulting electron distribution function was analyzed using Bader’s topological method. The density at bond critical points in the peptide unit shows some scatter in the correlation with bond length. Additionally, (3,−3) critical points (local minima) were located in ∇2ρ(r) within the valence shell charge concentration region of the carbonyl oxygen atoms. These points always lie near the plane of the peptide unit, which itself is sometimes not precisely planar. [Copyright &y& Elsevier]

Crambin is a small (46 amino acids) protein isolated from the seeds of the plant Crambe abyssinica. Crambin has been extensively used as a model protein for the development of advanced crystallography and NMR techniques and for computational folding studies. We set out to establish synthetic access to crambin. Initially, we synthesized the 46 amino acid polypeptide by native chemical ligation of two distinct sets of peptide segments (15 + 31 and 31 + 15 residues). The synthetic polypeptide chain folded in good yield to give native crambin containing three disulfide bonds. The chemically synthesized crambin was characterized by LC-MS and by 2D-NMR. However, the 31-residue peptide segments were difficult to purify, and this caused an overall low yield for the synthesis. To overcome this problem, we synthesized crambin by the native chemical ligation of three segments (15 + 16 + 15 residues). Total synthesis using the ligation of three segments gave more than a 10-fold increase in yield and a protein product of exceptionally high purity. This work demonstrates the efficacy of chemical protein synthesis by the native chemical ligation of three segments and establishes efficient synthetic access to the important model protein crambin for experimental studies of protein folding and stability. [ABSTRACT FROM AUTHOR]

The flavonoid profiles of 22 accessions of Camelina sativa and five other crucifer species, Crambe abyssinica, Crambe hispanica, Thlaspi arvense, Brassica napus, and Sinapis alba, were studied by a combination of liquid, paper and thin layer chromatography. Flavonoids were confirmed by comparison of their characteristics, including colour under UV light, changes to colour under UV with fuming in NH3 vapour, UV spectra and comparison of RF-values, with those of authentic standards. HPLC-mass spectroscopic data were obtained to confirm identities of several compounds. Flavonoids present in several other crucifer species were identified by TLC only. We report the accumulation of derivatives of the flavonols, quercetin, in C. sativa; quercetin and kaempferol in C. hispanica var. glabrata; quercetin, kaempferol and isorhamnetin in B. napus; and kaempferol and isorhamnetin in S. alba. Derivatives of the flavones, apigenin and luteolin, accumulate in C. abyssinica, C. hispanica var. hispanica and T. arvense leaves. [Copyright &y& Elsevier]

PEG-induced asymmetric somatic hybridization between Brassica napus and Crambe abyssinica was carried out. C. abyssinica is an annual cruciferous oil crop with a high content of erucic acid in the seed oil valuable for technical purposes. UV-irradiated mesophyll protoplasts of C. abyssinica cv 'Carmen' and cv 'Galactica' were fused with hypocotyl protoplasts of different genotypes of B. napus cv 'Maplus' and breeding line '11502'. Shoot regeneration frequency varied between 6.1% and 20.8% among the different doses of UV-irradiation, ranging from 0.05 J/cm2 to 0.30 J/cm2. In total, 124 shoots were regenerated, of which 20 asymmetric somatic hybrids were obtained and verified by nuclear DNA content and AFLP analysis. AFLP data showed that some of the characteristic bands from C. abyssinica were present in the hybrids. Cytological analysis of these hybrids showed that 9 out of 20 asymmetric hybrids had 38 chromosomes, the others contained 40–78 chromosomes, having additional chromosomes between 2 and 40 beyond the 38 expected for B. napus. The investigation into the fertility of asymmetric somatic hybrids indicated that the fertility increased with increasing UV-doses ranging from 0.05 J/cm2 to 0.15 J/cm2. All of the hybrids were cultured to full maturity, and could be fertilized and set seeds after self-pollination or backcrosses with B. napus. An analysis of fatty acid composition in the seeds was conducted and found to contain significantly greater amounts of erucic acid than B. napus. This study indicates that UV-irradiation could be used as a tool to produce asymmetric somatic hybrids and to promote the fertility of the hybrids. [ABSTRACT FROM AUTHOR]