Synthetic redesign of plant lipid metabolism.

Plant seed lipid metabolism is an area of intensive research, including many examples of transgenic events in which oil composition has been modified. In the selected examples described in this review, progress towards the predictive manipulation of metabolism and the reconstitution of desired traits in a non-native host is considered. The advantages of a particular oilseed crop, Camelina sativa, as a flexible and utilitarian chassis for advanced metabolic engineering and applied synthetic biology are considered, as are the issues that still represent gaps in our ability to predictably alter plant lipid biosynthesis. Opportunities to deliver useful bio-based products via transgenic plants are described, some of which represent the most complex genetic engineering in plants to date. Future prospects are considered, with a focus on the desire to transition to more (computationally) directed manipulations of metabolism.

Comparison of different cleanup procedures for oil crops based on the development of a trace analytical method for the determination of pyraclostrobin and epoxiconazole.

The effects of different cleanup procedures in removing high-molecular-mass lipids and natural colorants from oil-crop extracts, including dispersive solid-phase extraction, low-temperature precipitation and gel permeation chromatography, were studied. The pigment removal, lipid quantity, and matrix effects of the three cleanup methods were evaluated. Results indicated that the gel permeation chromatography method is the most effective way to compare the dispersive solid-phase extraction and low-temperature precipitation. Pyraclostrobin and epoxiconazole applied extensively in oil-crop production were selected as typical pesticides to study and a trace analytical method was developed by gel permeation chromatography and ultra high performance liquid chromatography with tandem mass spectrometry. Average recoveries of the target pesticides at three levels (10, 50, and 100 µg/kg) were in the range of 74.7-96.8% with relative standard deviation values below 9.2%. The limits of detection did not exceed 0.46 µg/kg, whereas the limits of quantification were below 1.54 µg/kg and much lower than maximum residue limit in all matrices. This study may provide the essential data for optimizing the analytical method of pesticides in oil-crop samples.

Vegetable oils: Classification, quality analysis, nutritional value and lipidomics applications.

Lipids are widespread in nature and play a pivotal role as a source of energy and nutrition for the human body. Vegetable oils (VOs) constitute a significant category in the food industry, containing various lipid components that have garnered attention for being natural, environmentally friendly and health-promoting. The review presented the classification of raw materials (RMs) from oil crops and quality analysis techniques of VOs, with the aim of improving comprehension and facilitating in-depth research of VOs. Brief descriptions were provided for four categories of VOs, and quality analysis techniques for both RMs and VOs were generalized. Furthermore, this study discussed the applications of lipidomics technology in component analysis, processing and utilization, quality determination, as well as nutritional function assessment of VOs. Through reviewing RMs and quality analysis techniques of VOs, this study aims to encourage further refinement and development in the processing and utilization of VOs, offering valuable references for theoretical and applied research in food chemistry and food science.

Contamination and Control of Mycotoxins in Grain and Oil Crops.

Mycotoxins are carcinogenic, teratogenic and mutagenic toxic compounds produced by some filamentous fungi, which are extremely harmful to corn, rice, wheat, peanut, soybean, rapeseed and other grain and oil crops, and seriously threaten environmental safety, food safety and human health. With the rapid increase in the global population and the expansion of the main crop planting area, mycotoxin contamination has increased year by year in agricultural products. The current review aimed to summarize the contamination status and harmful effects of major mycotoxins of grain and oil crops and the environmental factors that impact mycotoxin contamination. Further, control measures of mycotoxin contamination, especially the biological control strategies, were discussed.

Relevant mycotoxins in oil crops, vegetable oils, de-oiled cake and meals: Occurrence, control, and recent advances in elimination.

Mycotoxins in agricultural commodities have always been a concern due to their negative impacts on human and livestock health. Issues associated with quality control, hot and humid climate, improper storage, and inappropriate production can support the development of fungus, causing oil crops to suffer from mycotoxin contamination, which in turn migrates to the resulting oil, de-oiled cake and meals during the oil processing. Related research which supports the development of multi-mycotoxin prevention programs has resulted in satisfactory mitigation effects, mainly in the pre-harvest stage. Nevertheless, preventive actions are unlikely to avoid the occurrence of mycotoxins completely, so removal strategies may still be necessary to protect consumers. Elimination of mycotoxin has been achieved broadly through the physical, biological, or chemical course. In view of the steadily increasing volume of scientific literature regarding mycotoxins, there is a need for ongoing integrated knowledge systems. This work revisited the knowledge of mycotoxins affecting oilseeds, food oils, cake, and meals, focusing more on their varieties, toxicity, and preventive strategies, including the methods adopted in the decontamination, which supplement the available information.

Exploring the safe utilization strategy of calcareous agricultural land irrigated with wastewater for over 50 years.

The trace element (TE) contamination of farmland caused by wastewater irrigation threatens food security and food safety. We selected a typical calcareous soil area in western China that has been irrigated with wastewater for >50 years to explore safe use strategies for flax farmland contaminated by cadmium (Cd) and arsenic (As). We found that Cd and As were mainly accumulated in flax roots rather than seeds. However, regardless of the type of TE and acceptor, direct ingestion of the flaxseed would seriously endanger human health (hazard quotient >1). According to the results of redundancy analysis and Pearson correlation analysis, the concentration of Cd and As in flaxseed depended on the concentration of soil total TE, Olsen phosphorus, dissolved organic carbon, soil organic matter, and active calcium carbonate (CaCO3). This was largely because the pH and total CaCO3 content in topsoil of flax farmland decreased by 1.05 units and 37 %, respectively, compared with their background levels before wastewater irrigation. Interestingly, after pressing, Cd and As in flaxseed transferred to flaxseed oil were 3.87-10.55 % and 17.21-30.48 %, respectively, which led to an acceptable risk of adults and children (hazard quotient <1) consuming flaxseed oil. Our results suggest that with the production of flaxseed oil as the goal, the long-term wastewater-irrigated calcareous land can be safely utilized while obtaining income.

The impact of global warming on the potential suitable planting area of Pistacia chinensis is limited.

Pistacia chinensis Bunge. is one of the main woody oil crops with a large artificial planting area in China and has important economic and ecological value. Here, based on 237 occurrence data and 22 environmental variables, we explored the potential planting area of P. chinensis in China in the present and future climate change scenarios by using a comprehensive model method. To fully consider the potential planting area of P. chinensis under specific climate change conditions and the limitations of soil conditions, we separately built two niche models to simulate the climate niche and soil demand niche, and then used the intersection of the two models as the result of the comprehensive habitat suitability model, finally, we used land-use data to filter the CHS model result. Our results showed, that under the baseline condition, the potential planting area of P. chinensis covers approximately 0.74 × 106 km2 in China. The future projection showed that the impact of global warming on the potentially suitable planting area of P. chinensis is limited, and most of the existing suitable habitats are not affected by climate change. With increasing temperature, the potential planting area will expand northward and slightly contract in the south margin, and its area will be slightly increased. Therefore, this species has great planting potential in China and should be given priority in the future afforestation plan.

Symbiotic Fungi Alter the Acquisition of Phosphorus in Camellia oleifera through Regulating Root Architecture, Plant Phosphate Transporter Gene Expressions and Soil Phosphatase Activities.

Plant roots can be colonized by many symbiotic fungi, whereas it is unclear whether and how symbiotic fungi including arbuscular mycorrhizal fungi and endophytic fungi promote phosphorus (P) uptake in Camellia oleifera plants. The objective of the present study was to analyze the effect of inoculation with a culturable endophytic fungus (Piriformospora indica), three arbuscular mycorrhizal fungi (Funneliformis mosseae, Diversispora versiformis, and Rhizophagus intraradices), and mixture of F. mosseae, D. versiformis and R. intraradices on plant growth, root architecture, soil Olsen-P, soil phosphatase activities, leaf and root P concentrations, and phosphate transporter gene expressions, in order to explore the potential and mechanism of these symbiotic fungi on P acquisition. All the symbiotic fungi colonized roots of C. oleifera after 16 weeks, with P. indica showing the best effect on fungal colonization. All the symbiotic fungi significantly increased acid, neutral, and total phosphatase activities in the soil, accompanied with an elevation of soil Olsen-P, of which P. indica presented the best effect. All symbiotic fungal treatments, except D. versiformis, significantly promoted plant growth, coupled with an increase in root total length, area, and volume. Symbiotic fungi almost up-regulated root CoPHO1-3 expressions as well as leaf CoPHO1-1, CoPHO1-3, and CoPHT1;4 expressions. Correlation analysis showed that P concentrations in leaves and roots were significantly positively correlated with root morphological variables (length, volume, and surface area) and soil acid, neutral and total phosphatase activities. It is concluded that symbiotic fungi, especially P. indica, played an important role in P uptake of C. oleifera plants through regulating root architecture, part plant phosphate transporter gene expressions and soil phosphatase activities.

Development of a High Oleic Cardoon Cell Culture Platform by SAD Overexpression and RNAi-Mediated FAD2.2 Silencing.

The development of effective tools for the sustainable supply of phyto-ingredients and natural substances with reduced environmental footprints can help mitigate the dramatic scenario of climate change. Plant cell cultures-based biorefineries can be a technological advancement to face this challenge and offer a potentially unlimited availability of natural substances, in a standardized composition and devoid of the seasonal variability of cultivated plants. Monounsaturated (MUFA) fatty acids are attracting considerable attention as supplements for biodegradable plastics, bio-additives for the cosmetic industry, and bio-lubricants. Cardoon (Cynara cardunculus L. var. altilis) callus cultures accumulate fatty acids and polyphenols and are therefore suitable for large-scale production of biochemicals and valuable compounds, as well as biofuel precursors. With the aim of boosting their potential uses, we designed a biotechnological approach to increase oleic acid content through Agrobacterium tumefaciens-mediated metabolic engineering. Bioinformatic data mining in the C. cardunculus transcriptome allowed the selection and molecular characterization of SAD (stearic acid desaturase) and FAD2.2 (fatty acid desaturase) genes, coding for key enzymes in oleic and linoleic acid formation, as targets for metabolic engineering. A total of 22 and 27 fast-growing independent CcSAD overexpressing (OE) and CcFAD2.2 RNAi knocked out (KO) transgenic lines were obtained. Further characterization of five independent transgenic lines for each construct demonstrated that, successfully, SAD overexpression increased linoleic acid content, e.g., to 42.5%, of the relative fatty acid content, in the CcSADOE6 line compared with 30.4% in the wild type (WT), whereas FAD2.2 silencing reduced linoleic acid in favor of the accumulation of its precursor, oleic acid, e.g., to almost 57% of the relative fatty acid content in the CcFAD2.2KO2 line with respect to 17.7% in the WT. Moreover, CcSADOE6 and CcFAD2.2KO2 were also characterized by a significant increase in total polyphenolic content up to about 4.7 and 4.1 mg/g DW as compared with 2.7 mg/g DW in the WT, mainly due to the accumulation of dicaffeoyl quinic and feruloyl quinic acids. These results pose the basis for the effective creation of an engineered cardoon cells-based biorefinery accumulating high levels of valuable compounds from primary and specialized metabolism to meet the industrial demand for renewable and sustainable sources of innovative bioproducts.

Assessment of the potential for phytoremediation of cadmium polluted soils by various crop rotation patterns based on the annual input and output fluxes.

Phytoremediation potential of two oil crop rotations (oilseed sunflower-rape (O+Ra) and peanut-oilseed rape (P+Ra)) was compared with three conventional cropping patterns (rice-rape (R+Ra), rice-rice (R+R), single cropped rice (SR)) in experimental plots with cadmium (Cd)-contaminated soil. A new approach was used to evaluate phytoremediation potential based on the balance between annual input and output fluxes of Cd in farmland soil. In O+Ra and P+Ra rotations, 77.24 and 62.09 g/ha Cd were removed, respectively, whereas in R+Ra, R+R, and SR patterns, 41.79, 46.46, and 23.85 g/ha Cd were removed, respectively. The balance between inputs and outputs of Cd was - 40.72 and - 25.76 g/ha under O+Ra and P+Ra rotations, respectively. Available Cd content in topsoil was reduced by 5.58% and 3.91% under O+Ra and P+Ra rotations, respectively. Based on the balance between Cd inputs and outputs, phytoremediation efficiencies of O+Ra (1.23%) and P+Ra (0.78%) rotations were higher than those of R+R (0.29%), R+Ra (0.13%), and SR (-0.38%) systems. Because crop removal is the main Cd output pathway, selection of a suitable crop is particularly important in remediation of Cd-contaminated farmland.

Fatty Acid Composition of Cannabis sativa, Linum usitatissimum and Camelina sativa Seeds Harvested in Lithuania for Food Use.

The objective of this study was to determine species-associated differences in the seed proximate and fatty acid composition of three traditional oil crop species, hemp (Cannabis sativa), flax (Linum usitatissimum), and camelina (Camelina sativa), and the sowing season of camelina harvested under Lithuanian farming conditions for food use. Camelina seeds had the highest (p < 0.001) content of protein, oil, and sugar contents compared to both dehulled hemp and flax seeds. The amounts of protein and oil in camelina seeds were considerably increased by their summer cultivar, which showed higher (p < 0.001) contents of protein and oil than winter cultivars. However, the highest and lowest (p < 0.001) fiber content was found in flax seeds and camelina seeds, respectively. Camelina seeds showed considerably higher and lower (p < 0.001) proportions of total monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids, respectively, compared with hemp and flax. The summer cultivar of camelina had higher (p < 0.001) proportions of saturated (SFA) and MUFA and lower proportions of PUFA compared with winter cultivars. Hemp seeds had the highest and lowest (p < 0.001) proportions of PUFA and MUFA, respectively. The n-6/n-3 PUFA ratio in hemp seeds is optimal (3.79), whereas the use of flax and camelina seeds with their n-6/n-3 ratios of 0.28 and 0.48, respectively, can significantly improve this ratio in the overall diet. The properties of oil crop seeds showed that whole seeds of hemp, flax, and camelina are potentially highly beneficial to human health.

A Review of Nervonic Acid Production in Plants: Prospects for the Genetic Engineering of High Nervonic Acid Cultivars Plants.

Nervonic acid (NA) is a very-long-chain monounsaturated fatty acid that plays crucial roles in brain development and has attracted widespread research interest. The markets encouraged the development of a refined, NA-enriched plant oil as feedstocks for the needed further studies of NA biological functions to the end commercial application. Plant seed oils offer a renewable and environmentally friendly source of NA, but their industrial production is presently hindered by various factors. This review focuses on the NA biosynthesis and assembly, NA resources from plants, and the genetic engineering of NA biosynthesis in oil crops, discusses the factors that affect NA production in genetically engineered oil crops, and provides prospects for the application of NA and prospective trends in the engineering of NA. This review emphasizes the progress made toward various NA-related topics and explores the limitations and trends, thereby providing integrated and comprehensive insight into the nature of NA production mechanisms during genetic engineering. Furthermore, this report supports further work involving the manipulation of NA production through transgenic technologies and molecular breeding for the enhancement of crop nutritional quality or creation of plant biochemical factories to produce NA for use in nutraceutical, pharmaceutical, and chemical industries.

Working with Randy: The Diacylglycerol Acyltransferase Story.

Vegetable oils are one of the main agricultural commodities. Demand has been increasing steadily over the last five decades and, with finite land available, it is vital that we increase productivity. My laboratory has focused on the regulation of plant lipid metabolism and, as part of this work, we identified diacylglycerol acyltransferase (DGAT) as important at regulating carbon flux during oil accumulation. This led to collaborations with Randy Weselake's research group when we quantified the importance of DGAT in oilseed rape by using flux control analysis. Later, with David Taylor, we showed that over-expression of DGAT boosted oil accumulation in field-grown crops by around 8%. These studies led to a multitude of experiments with different oil crops, such as oil palm and soybean, as well as many rewarding collaborations with Randy.

Ultra-performance liquid chromatography-mass spectrometry for precise fatty acid profiling of oilseed crops.

Oilseed crops are one of the most important sources of vegetable oils for food and industry. Nutritional and technical properties of vegetable oil are primarily determined by its fatty acid (FA) composition. The content and composition of FAs in plants are commonly determined using gas chromatography-mass spectrometry (GS-MS) or gas chromatography-flame ionization detection (GC-FID) techniques. In the present work, we applied ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) technique to FA profiling of sunflower and rapeseed seeds and compared this method with the GC-FID technique. GC-FID detected 11 FAs in sunflower and 13 FAs in rapeseed, while UPLC-MS appeared to be more sensitive, detecting about 2.5 times higher numbers of FAs in both plants. In addition to even-chain FAs, UPLC-MS was able to detect odd-chain FAs. The longest FA detected using GC-FID was an FA with 24 carbon atoms, whereas UPLC-MS could reveal the presence of longer FAs with the tails of up to 28 carbon atoms. Based on our results, we may conclude that UPLC-MS has great potential to be used for the assessment of FA profiles of oil crops.

Properties and Biotechnological Applications of Acyl-CoA:diacylglycerol Acyltransferase and Phospholipid:diacylglycerol Acyltransferase from Terrestrial Plants and Microalgae.

Triacylglycerol (TAG) is the major storage lipid in most terrestrial plants and microalgae, and has great nutritional and industrial value. Since the demand for vegetable oil is consistently increasing, numerous studies have been focused on improving the TAG content and modifying the fatty-acid compositions of plant seed oils. In addition, there is a strong research interest in establishing plant vegetative tissues and microalgae as platforms for lipid production. In higher plants and microalgae, TAG biosynthesis occurs via acyl-CoA-dependent or acyl-CoA-independent pathways. Diacylglycerol acyltransferase (DGAT) catalyzes the last and committed step in the acyl-CoA-dependent biosynthesis of TAG, which appears to represent a bottleneck in oil accumulation in some oilseed species. Membrane-bound and soluble forms of DGAT have been identified with very different amino-acid sequences and biochemical properties. Alternatively, TAG can be formed through acyl-CoA-independent pathways via the catalytic action of membrane-bound phospholipid:diacylglycerol acyltransferase (PDAT). As the enzymes catalyzing the terminal steps of TAG formation, DGAT and PDAT play crucial roles in determining the flux of carbon into seed TAG and thus have been considered as the key targets for engineering oil production. Here, we summarize the most recent knowledge on DGAT and PDAT in higher plants and microalgae, with the emphasis on their physiological roles, structural features, and regulation. The development of various metabolic engineering strategies to enhance the TAG content and alter the fatty-acid composition of TAG is also discussed.

Functional and Structural Diversity of Acyl-coA Binding Proteins in Oil Crops.

Diversities in structure and function of ACBP were discussed in this review. ACBP are important proteins that could transport newly synthesized fatty acid, activated into -coA, from plastid to endoplasmic reticulum, where oil in the form of triacylglycerol occurs. ACBP were detected in various animal and plants species, which indicated their importance in biological function. In fact, involvement of ACBP in important process such as lipid metabolism, regulation of enzyme and gene expression, and in response to plant stresses has been proven in several studies. In this review, findings on ACBP of 11 well-known oil crops were reviewed to comprehend diversity, comparative analyses on ACBP structure were made, and link between structure and function, tissue expression and subcellular location of ACBP were also observed. Incomplete reports in some species were mentioned, which might be encouraging to start or to perform deeper studies. Similar characteristics were found in paralogs ACBP, and orthologs ACBP had different functions, despite the high identity in amino acid sequence. At the end, it is confirmed that ortholog proteins could not necessarily display the same function, even from closely related species.

[Simultaneous determination of six novel acetolactate synthase inhibitor herbicide residues in oil crops based on ultrasound assisted extraction liquid chromatography-tandem mass spectrometry].

Ultrasound-assisted extraction coupled with liquid chromatography-tandem mass spectrometry (UAE-LC-MS/MS) was used to develop a trace multi-residue detection method for six novel acetolactate synthase (ALS) inhibitor herbicide residues (mesosulfuron-methyl, halosulfuron-methyl, bispyribac-sodium, pyriminobac-methyl, orthosulfamuron, and ethoxysulfuron) in oil crops. In this study, the recoveries of the six herbicides based on ultrasound-assisted and QuEChERS extraction methods were compared, and five adsorbent materials (C18, PSA, GCB, Florisil, and EMR) were optimized based on their purification and adsorption capacities. The results showed that the ultrasound-assisted extractions gave recoveries greater than 90% for the six compounds. Furthermore, EMR showed little adsorption for the six compounds and a reduced matrix effect by effective removal of the oil lipids. The six herbicide residues had good linearities in the concentrations ranging from 0.05 to 500.0 µg/L, and the correlation coefficients were greater than 0.9984. The limits of detection and limits of quantification for this method were 0.08-0.8 µg/kg and 0.25-2.5 µg/kg, respectively. The recoveries of the six pesticides at three spiked levels in four matrices (rapeseed, soybean, peanut, and sunflower seed) ranged from 70.7% to 103.8%, with relative standard deviations of 0.8%-9.2%. This method was successfully applied to the simultaneous determination of six ALS inhibitor herbicide residues in oil crops.

Comparative life cycle assessment study on environmental impact of oil production from micro-algae and terrestrial oilseed crops.

In this study the LCA methodology is applied in order to satisfy two goals: i) to evaluate the hot spots in site-specific production chain of biodiesel from terrestrial and micro-algae feedstock; ii) to compare quantitatively, utilizing primary data, the impacts of the first generation in respect to the third generation bio-fuels. Results show that micro-algae are neither competitive yet with traditional oil crops nor with fossil fuel. The use of renewable technologies as photovoltaics and biogas self production might increase the competitiveness of micro-algae oil. Further investigations are however necessary to optimize their production chain and to increase the added value of co-products.

Comparison of three types of oil crop rotation systems for effective use and remediation of heavy metal contaminated agricultural soil.

Selecting suitable plants tolerant to heavy metals and producing products of economic value may be a key factor in promoting the practical application of phytoremediation polluted soils. The aim of this study is to further understand the utilization and remediation of seriously contaminated agricultural soil. In a one-year field experiment, we grew oilseed rape over the winter and then subsequently sunflowers, peanuts and sesame after the first harvest. This three rotation system produced high yields of dry biomass; the oilseed rape-sunflower, oilseed rape-peanut and oilseed rape-sesame rotation allowed us to extract 458.6, 285.7, and 134.5 g ha-1 of cadmium, and 1264.7, 1006.1, and 831.1 g ha-1 of lead from soil, respectively. The oilseed rape-sunflower rotation showed the highest phytoextraction efficiency (1.98%) for cadmium. Lead and cadmium in oils are consistent with standards after extraction with n-hexane. Following successive extractions with potassium tartrate, concentrations of lead and cadmium in oilseed rape and peanut seed meals were lower than levels currently permissible for feeds. Thus, this rotation system could be useful for local farmers as it would enable the generation of income during otherwise sparse phytoremediation periods.