Seed Oil Bodies Research Articles

Physicochemical and digestive characteristics of high internal phase emulsion based on pumpkin seed oil bodies prepared at different pHs

In this study, we prepared high internal phase emulsions based on pumpkin seed oil body (HIPEs-PSOB) with 83% oil phase at pH 6.5, pH 9.0 and pH 11.0. The pH 11.0-HIPE-PSOB contained almost oleosin of 14.5 kDa, while other HIPEs-PSOB had oleosin and extrinsic proteins. With the increase of extraction pHs, the content of bound water, immobilized water, particle size, viscosity, viscoelastisity and shear stress decreased, and the free water and isoelectric point of HIPEs-PSOB increased. During stomach digestion, the hydrolysis rate of extrinsic proteins of all HIPEs-PSOB was higher than that of oleosin, and the proteins were hydrolyzed to produce resistant peptides. CLSM showed that all HIPEs-PSOB coalesced during gastric and the droplets were significantly reduced and dispersed in the intestine. The total FFA release decreased with the increase in extraction pH. This study provided a theoretical basis for the investigation and application of OBs and HIPEs.

Role of particle size-dependent copper bioaccumulation-mediated oxidative stress on Glycine max (L.) yield parameters with soil-applied copper oxide nanoparticles

Increased impetus on the application of nano-fertilizers to improve sustainable food production warrants understanding of nanophytotoxicity and its underlying mechanisms before its application could be fully realized. In this study, we evaluated the potential particle size-dependent effects of soil-applied copper oxide nanoparticles (nCuO) on crop yield and quality attributes (photosynthetic pigments, seed yield and nutrient quality, seed protein, and seed oil), including root and seed Cu bioaccumulation and a suite of oxidative stress biomarkers, in soybean (Glycine max L.) grown in field environment. We synthesized three distinct sized (25 nm = S [small], 50 nm = M [medium], and 250 nm = L [large]) nCuO with same surface charge and compared with soluble Cu2+ ions (CuCl2) and water-only controls. Results showed particle size-dependent effects of nCuO on the photosynthetic pigments (Chla and Chlb), seed yield, potassium and phosphorus accumulation in seed, and protein and oil yields, with nCuO-S showing higher inhibitory effects. Further, increased root and seed Cu bioaccumulation led to concomitant increase in oxidative stress (H2O2, MDA), and as a response, several antioxidants (SOD, CAT, POX, and APX) increased proportionally, with nCuO treatments including Cu2+ ion treatment. These results are corroborated with TEM ultrastructure analysis showing altered seed oil bodies and protein storage vacuoles with nCuO-S treatment compared to control. Taken together, we propose particle size-dependent Cu bioaccumulation-mediated oxidative stress as a mechanism of nCuO toxicity. Future research investigating the potential fate of varied size nCuO, with a focus on speciation at the soil-root interface, within the root, and edible parts such as seed, will guide health risk assessment of nCuO.Graphical

Degeneration of oil bodies by rough endoplasmic reticulum -associated protein during seed germination in Cannabis sativa.

Oil bodies serve as a vital energy source of embryos during germination and contribute to sustaining the initial growth of seedlings until photosynthesis initiation. Despite high stability in chemical properties, how oil bodies break down and go into the degradation process during germination is still unknown. This study provides a morphological understanding of the mobilization of stored compounds in the seed germination of Cannabis. The achenes of fibrous hemp cultivar (Cannabis sativa cv. 'Chungsam') were examined in this study using light microscopy, scanning electron microscopy and transmission electron microscopy. Oil bodies in Cannabis seeds appeared spherical and sporadically distributed in the cotyledonary cells. Protein bodies contained electron-dense globoid and heterogeneous protein matrices. During seed germination, rough endoplasmic reticulum (rER) and high electron-dense substances were present adjacent to the oil bodies. The border of the oil bodies became a dense cluster region and appeared as a sinuous outline. Later, irregular hyaline areas were distributed throughout oil bodies, showing the destabilized emulsification of oil bodies. Finally, the oil bodies lost their morphology and fused with each other. The storage proteins were concentrated in the centre of the protein body as a dense homogenous circular mass surrounded by a light heterogeneous area. Some storage proteins are considered emulsifying agents on the surface region of oil bodies, enabling them to remain stable and distinct within and outside cotyledon cells. At the early germination stage, rER appeared and dense substances aggregated adjacent to the oil bodies. Certain proteins were synthesized within the rER and then translocated into the oil bodies by crossing the half membrane of oil bodies. Our data suggest that rER-associated proteins function as enzymes to lyse the emulsifying proteins, thereby weakening the emulsifying agent on the surface of the oil bodies. This process plays a key role in the degeneration of oil bodies and induces coalescence during seed germination.

Preparation of high internal phase emulsions based on pumpkin seed oil body and its physicochemical properties

In this study, we successfully prepared high internal phase emulsions (HIPEs) with 78%–90% oil phase based on pumpkin seed oil bodies (PSOBs) extracted by neutral extraction at 2800×g to 31000×g. There were no effects on the protein compositions and contents of PSOBs by different centrifugal forces. PSOBs included oleosin (14.5 kDa) and extrinsic proteins (22 kDa, 27 kDa, 33 kDa, 45 kDa). The HIPE-PSOB with 78% oil phase had relatively spherical droplets, which was similar to the PSOB with 72% oil phase extracted at 1000×g, while 83%–90% of the oil phase displayed polygonal droplets. All HIPEs-PSOB had gel-like properties, and HIPEs-PSOB with a higher oil phase had a better storage modulus. With the increase in the oil phase, the particle sizes increased, and the gel network structure, viscoelasticity, freeze‒thaw stability and oxidation stability improved, while the thermal stability worsened. This study offers guidance for expanding the application of OBs in food.

Addressing global food insecurity: Soil-applied zinc oxide nanoparticles promote yield attributes and seed nutrient quality in Glycine max L.

Consumed globally, oilseeds serve as a major source of proteins and oils in human and animal nutrition, supporting global food security. Zinc (Zn) is an essential micronutrient critical for oil and protein synthesis in plants. In this study, we synthesized three distinct sized zinc oxide nanoparticles (nZnO: 38 nm = S [small], 59 nm = M [medium], and > 500 nm = L [large], and assessed the potential effects of varied particle sizes and concentrations (0, 50, 100, 200, and 500 mg/kg-soil) on seed yield attributes, nutrient quality and oil and protein yield in soybean (Glycine max L.) grown for a full lifecycle of 120 days, and compared with soluble Zn2+ ions (ZnCl2) and water-only controls. We observed particle size- and concentration-dependent influence of nZnO on photosynthetic pigments, pod formation, potassium and phosphorus accumulation in seed, and protein and oil yields. Overall, soybean showed significant stimulatory responses to nZnO-S for most of the parameters tested compared to nZnO-M, nZnO-L, and Zn2+ ions treatments up to 200 mg/kg, suggesting the potential for small size nZnO to improve seed quality and production in soybean. At 500 mg/kg, however, for all endpoints (except for carotenoids and seed formation) toxicity was observed with all Zn compounds. Further, TEM analysis of seed ultrastructure indicated potential alterations in seed oil bodies and protein storage vacuoles at a toxic concentration (500 mg/kg) of nZnO-S compared to control. These findings suggest 200 mg/kg as an optimal dose for the smallest size nZnO-S (38 nm) to significantly improve seed yield, nutrient quality, and oil and protein yield, paving a path for addressing global food insecurity using small sized nZnO as a novel nano-fertilizer to promote crop yield and nutrient quality, in soil-grown soybean.

Analysis of oil synthesis pathway in Cyperus esculentus tubers and identification of oleosin and caleosin genes

The tubers of the widely distributed Cyperus esculentus are rich in oil, and therefore, the plant is considered to have a high utilization value in the vegetable oil industry. Oleosins and caleosins are lipid-associated proteins found in oil bodies of seeds; however oleosins and caleosins genes have not been identified in C. esculentus. In this study, we performed transcriptome sequencing and lipid metabolome analysis of C. esculentus tubers at four developmental stages to obtain the information on their genetic profile, expression trends, and metabolites in oil accumulation pathways. Overall, 120,881 non-redundant unigenes and 255 lipids were detected; 18 genes belonged to the acetyl-CoA carboxylase (ACC), malonyl-CoA:ACP transacylase (MCAT), β-ketoacyl-ACP synthase (KAS), and fatty acyl-ACP thioesterase (FAT) gene families involved in fatty acid biosynthesis, and 16 genes belonged to the glycerol-3-phosphate acyltransferase (GPAT), diacylglycerol acyltransferase 3 (DGAT3), phospholipid:diacylglycerol acyltransferase (PDAT), FAD2, and lysophosphatidic acid acyltransferase (LPAAT) gene families playing important roles in triacylglycerol synthesis. We also identified 9 oleosin- and 21 caleosin-encoding genes in C. esculentus tubers. These results provide detailed information on the C. esculentus transcriptional and metabolic profiles, which can be used as reference for the development of strategies to increase oil content in C. esculentus tubers.

Lysophosphatidic acid acyltransferase 2 and 5 commonly, but differently, promote seed oil accumulation in Brassica napus

BackgroundIncreasing seed oil content (SOC) of Brassica napus has become one of the main plant breeding goals over the past decades. Lysophosphatidic acid acyltransferase (LPAT) performs an important molecular function by regulating the production of phosphatidic acid (PA), a key intermediate in the synthesis of membrane and storage lipids. However, the mechanism underlying the effect of LPAT on the SOC of B. napus remains unclear.ResultsIn the present study, significant elevation of SOC was achieved by overexpressing BnLPAT2 and BnLPAT5 in B. napus. RNAi and CRISPR–Cas9 were also successfully used to knock down and knock out these two genes in B. napus where SOC significantly decreased. Meanwhile, we found an accumulation of lipid droplets and oil bodies in seeds of BnLPAT2 and BnLPAT5 overexpression lines, whereas an increase of sugar and protein in Bnlpat2 and Bnlpat5 mutant seeds. Sequential transcriptome analysis was further performed on the developing seeds of the BnLPAT2 and BnLPAT5 overexpression, knockdown, and knockout rapeseed lines. Most differentially expressed genes (DEGs) that were expressed in the middle and late stages of seed development were enriched in photosynthesis and lipid metabolism, respectively. The DEGs involved in fatty acid and lipid biosynthesis were active in the overexpression lines but were relatively inactive in the knockdown and knockout lines. Further analysis revealed that the biological pathways related to fatty acid/lipid anabolism and carbohydrate metabolism were specifically enriched in the BnLPAT2 overexpression lines.ConclusionsBnLPAT2 and BnLPAT5 are essential for seed oil accumulation. BnLPAT2 preferentially promoted diacylglycerol synthesis to increase SOC, whereas BnLPAT5 tended to boost PA synthesis for membrane lipid generation. Taken together, BnLPAT2 and BnLPAT5 can jointly but differently promote seed oil accumulation in B. napus. This study provides new insights into the potential mechanisms governing the promotion of SOC by BnLPAT2 and BnLPAT5 in the seeds of B. napus.

Bacillus subtilis biofilm matrix components target seed oil bodies to promote growth and anti-fungal resistance in melon

Beneficial microorganisms are used to stimulate the germination of seeds; however, their growth-promoting mechanisms remain largely unexplored. Bacillus subtilis is commonly found in association with different plant organs, providing protection against pathogens or stimulating plant growth. We report that application of B. subtilis to melon seeds results in genetic and physiological responses in seeds that alter the metabolic and developmental status in 5-d and 1-month-old plants upon germination. We analysed mutants in different components of the extracellular matrix of B. subtilis biofilms in interaction with seeds and found cooperation in bacterial colonization of seed storage tissues and growth promotion. Combining confocal microscopy with fluorogenic probes, we found that two specific components of the extracellular matrix, amyloid protein TasA and fengycin, differentially increased the concentrations of reactive oxygen species inside seeds. Further, using electron and fluorescence microscopy and metabolomics, we showed that both TasA and fengycin targeted the oil bodies in the seed endosperm, resulting in specific changes in lipid metabolism and accumulation of glutathione-related molecules. In turn, this results in two different plant growth developmental programmes: TasA and fengycin stimulate the development of radicles, and fengycin alone stimulate the growth of adult plants and resistance in the phylloplane to the fungus Botrytis cinerea. Understanding mechanisms of bacterial growth promotion will enable the design of bespoke growth promotion strains.

Oil Body Emulsion after Soybean Seed Germination Study on Stability

Soybean was used as raw material, and the oil emulsion of soybean seeds after germination was taken as the research object. Measurement of emulsion stability, peroxide value, thiobarbituric acid value (TBARS value) and acid value, the stability of oil emulsion of soybean seeds at different germination times was compared, and the effects of different treatment conditions (NaCl concentration, pH and storage temperature) on the stability of oil emulsion of soybean seeds after germination were studied. The experimental results showed that the oil bodies extraction rate of soybean seeds decreased gradually after germination, There was no significant difference in the extraction rate between 20 h (12.36%±0.21%) and 27 h (10.89%±0.28%) (P>0.05), and the extraction rate decreased significantly after 27 h (P 0.05). The emulsifying stability showed a downward trend when NaCl concentration was 0~150 mmol/L, and no significant change when NaCl concentration was higher than 150 mmol/L. The emulsifying stability was (4.75±0.12) min and (4.74±0.14) min when NaCl concentration was 150 and 200 mmol/L, respectively. However, the peroxide value increased significantly during 0~6 d of storage (P<0.05).The higher the pH was, the smaller the ζ-potential and emulsifying activity of the emulsion were. When the pH was 4, the emulsifying activity was (19.13±0.23) m2/g, and the peroxide value and TBARS value changed significantly (P<0.05). The emulsion stability of soybean seed oil body at different germination time was different, and soybean oil body after 27 h germination was more stable than other germination time. NaCl concentration and pH had great effect on the stability of germinated soybean oil emulsion, and storage temperature had little effect on it. It could provide theoretical basis for the application of germinated soybean oil bodies in the future.

Structural and Physicochemical Characteristics of Oil Bodies from Hemp Seeds (Cannabis sativa L.).

The structural and physicochemical characteristics of oil bodies from hemp seeds were explored in this study. Oil bodies from several plant-based sources have been previously studied; however, this is the first time a characterisation of oil bodies from the seeds of industrial hemp is provided. The morphology of oil bodies in hemp seeds and after extraction was investigated using cryo-scanning electron microscopy (cryo-SEM), and the interfacial characteristics of isolated oil bodies were studied by confocal laser scanning microscopy (CLSM). Proteins associated with oil bodies were characterised using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The effect of pH and ionic strength on colloidal properties of the oil bodies was investigated. Oil bodies in hemp seeds appeared spherical and sporadically distributed in the cell, with diameters of 3 to 5 μm. CLSM images of isolated oil bodies revealed the uniform distribution of phospholipids and proteins at their interface. Polyunsaturated fatty acids were predominant in the lipid fraction and linoleic acid accounted for ≈61% of the total fatty acids. The SDS-PAGE analysis of washed and purified oil bodies revealed major bands at 15 kDa and 50–25 kDa, which could be linked to membrane-specific proteins of oil bodies or extraneous proteins. The colloidal stability of oil bodies in different pH environments indicated that the isoelectric point was between pH 4 and 4.5, where oil bodies experienced maximum aggregation. Changes in the ionic strength decreased the interfacial charge density of oil bodies (ζ-potential), but it did not affect their mean particle size. This suggested that the steric hindrance provided by membrane-specific proteins at the interface of the oil bodies could have prevented them from flocculation at low interfacial charge density. The results of this study provide new tertiary knowledge on the structure, composition, and colloidal properties of oil bodies extracted from hemp seeds, which could be used as natural emulsions or lipid-based delivery systems for food products.

Deciphering the properties of hemp seed oil bodies for food applications: Lipid composition, microstructure, surface properties and physical stability

Hemp seed oil bodies (HSOBs) are of growing interest in response to the demand of consumers for healthy and natural plant-based food formulations. In this study, we used minimal processing including aqueous extraction by grinding and centrifugation to obtain HSOBs. We determined the lipid composition of HSBOs, their microstructure, and the impact of the homogenization pressure, pH and minerals on their surface properties and the physical stability of the emulsions. HSOBs contain high levels of well-balanced PUFA with LA/ALA = 2.9, γ-tocopherol, lutein and phytosterols. The mean diameter of HSOBs was 2.3 ± 0.1 μm with an isoelectric point in the range of pH 4.4 to 4.6. Homogenization of hemp seed extracts induced a decrease in the size of HSOBs but did not eliminate the sedimentation of the protein bodies composed of the globulin edestin. By changing the surface properties of HSOBs, pH values below 6 and NaCl induced the aggregation of HSOBs, while CaCl2 induced both aggregation and membrane-fusion mediated coalescence of HSOBs by involving probably the anionic phospholipids together with membrane proteins. This study will contribute to extend the range of novel food products and designed emulsions containing hemp seed proteins and oil bodies.

The stability and gastro-intestinal digestion of curcumin emulsion stabilized with soybean oil bodies

The study aimed at stabilizing the curcumin emulsions (CEs) using the soybean seed oil bodies (SSOBs) and investigated the gastrointestinal digestion of the CEs. The particle size decreased (P < 0.05) with the increasing concentration of SSOBs from 1.0 wt% to 5.0 wt%. The CEs stabilized with the SSOBs exhibited excellent stability at pH 2.0 and 6.0–10.0. The CEs were stable against the aggregation at 100–500 mmol/L NaCl concentration and elevated temperature. The droplet size analysis and confocal laser scanning microscope observation results indicated that the fat droplets aggregated in the CEs under the gastric conditions at 30 min and afterward it gradually dispersed. Under the simulated intestinal condition, the droplet size of the CEs significantly decreased compared to the simulated gastric conditions (P < 0.05). The release rate of curcumin continuously increased during 180 min digestion under the intestinal conditions. Therefore, SSOBs could be used as the natural emulsifiers and novel carriers in delivering the lipophilic bioactive compounds.

Deciphering the transcriptional regulatory networks that control size, color, and oil content in Brassica rapa seeds

BackgroundBrassica rapa is an important oilseed and vegetable crop species and is the A subgenome donor of two important oilseed Brassica crops, Brassica napus and Brassica juncea. Although seed size (SZ), seed color (SC), and oil content (OC) substantially affect seed yield and quality, the mechanisms regulating these traits in Brassica crops remain unclear.ResultsWe collected seeds from a pair of B. rapa accessions with significantly different SZ, SC, and OC at seven seed developmental stages (every 7 days from 7 to 49 days after pollination), and identified 28,954 differentially expressed genes (DEGs) from seven pairwise comparisons between accessions at each developmental stage. K-means clustering identified a group of cell cycle-related genes closely connected to variation in SZ of B. rapa. A weighted correlation analysis using the WGCNA package in R revealed two important co-expression modules comprising genes whose expression was positively correlated with SZ increase and negatively correlated with seed yellowness, respectively. Upregulated expression of cell cycle-related genes in one module was important for the G2/M cell cycle transition, and the transcription factor Bra.A05TSO1 seemed to positively stimulate the expression of two CYCB1;2 genes to promote seed development. In the second module, a conserved complex regulated by the transcription factor TT8 appear to determine SC through downregulation of TT8 and its target genes TT3, TT18, and ANR. In the third module, WRI1 and FUS3 were conserved to increase the seed OC, and Bra.A03GRF5 was revealed as a key transcription factor on lipid biosynthesis. Further, upregulation of genes involved in triacylglycerol biosynthesis and storage in the seed oil body may increase OC. We further validated the accuracy of the transcriptome data by quantitative real-time PCR of 15 DEGs. Finally, we used our results to construct detailed models to clarify the regulatory mechanisms underlying variations in SZ, SC, and OC in B. rapa.ConclusionsThis study provides insight into the regulatory mechanisms underlying the variations of SZ, SC, and OC in plants based on transcriptome comparison. The findings hold great promise for improving seed yield, quality and OC through genetic engineering of critical genes in future molecular breeding.

Characteristics of Paeonia ostii seed oil body and OLE17.5 determining oil body morphology

Paeonia ostii is an emerging woody oil crop and cultivated on a large scale in China. This study attempted to characterize the characteristics of P. ostii seed oil body (OB) and found the key genes related to its morphology. The results showed that P. ostii seed oil contained five dominant fatty acid compositions that were stored in OBs. During the development of seeds, oil yield and fatty acid content were in line with OB accumulation. Moreover, NaCl concentration and pH value could influence P. ostii OB stability. Additionally, oleosins (OLEs) were identified as the most abundant proteins in OBs. Based on the expression levels of OLEs, PoOLE17.5 was isolated, which might be localized in OBs. And overexpression of PoOLE17.5 in tobacco obviously increased seed size and hundred-seed weight, altered OB morphology and increased fatty acid content. These results could provide a theoretical basis for improving oil yield of P. ostii seeds.

Enrichment Analysis of Differentially Expressed Genes during Endosperm Grouting Periods in Non-waxy and Waxy Foxtail Millets

The content of amylose and amylopectin is an important trait affecting cooking and eating quality in millet. During process of kernel grouting, the synthesis of starch involves different pathways and components in non-waxy and waxy millets. Immature grouting grains of waxy millet ‘Gonggu68’ and non-waxy millet ‘Chigu4’ (grouting period 1 and 5 days) were used to analyze their transcriptome sequences by using Illumina Hiseq4000. The results showed that: (1) GBSSⅠ enzymes activity of waxy and non-waxy millet was low-high-low. There were some differences between the two activities. 665 upregulated differentially expressed genes were screened on day 5 and day 1 during grouting period in waxy cultivar ‘Gonggu68’, there were 431 more upregulated genes than downregulated genes. There were 97 more up-regulated genes than down-regulated genes in non-waxy cultivar ‘Chigu4’ on day 5 and day 1 in grouting period. (2) In the A 2 -VS-A 1 waxy comparison group, the differential genes were mainly GO enriched in 7 functions such as the seed oil body biogenic function, 17-β-ketosteroid reductase activity function and so on. it was mainly enriched in biological processes and molecular functions. In the B 2 -VS-B 1 non-waxy comparison group, the differential genes were mainly GO enriched in 8 functions such as the light capturing function and the pigment binding function in the light system I for non-waxy millet. (3) Differentially expressed genes were mainly KEGG enriched in caffeine metabolism pathway, linoleic acid metabolism pathway, anthocyanin biosynthesis pathway, aflatoxin biosynthesis pathway in waxy A 2 -VS-A 1 , but which were mainly KEGG enriched in the synergy-antenna protein pathway, the linoleic acid metabolic pathway, the caffeine metabolic pathway, the brassinosteroid biopathway in non-waxy B 2 -VS-B 1 . These two comparative groups were enriched Caffeine metabolism pathway and linoleic acid metabolism pathway appeared in the process. (4) Three ( SSII-3 , PHO1 , AS ) and four ( PHO1-1 , AS , AGP16 , WAXY ) genes with significant differences and related to waxy and non-waxy millet were screened. With Actin (Si001873) as the internal reference gene, the above seven differentially expressed genes were verified by qRT-PCR, which was consistent with the transcriptome results, indicating that the differentially expressed genes were related to waxy or non-waxy endosperm.

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development.

Oil bodies (OBs) are ubiquitous dynamic organelles found in plant seeds. They have attracted increasing attention recently because of their important roles in plant physiology. First, the neutral lipids stored within these organelles serve as an initial, essential source of energy and carbon for seed germination and post-germinative growth of the seedlings. Secondly, they are involved in many other cellular processes such as stress responses, lipid metabolism, organ development, and hormone signaling. The biological functions of seed OBs are dependent on structural proteins, principally oleosins, caleosins, and steroleosins, which are embedded in the OB phospholipid monolayer. Oleosin and caleosin proteins are specific to plants and mainly act as OB structural proteins and are important for the biogenesis, stability, and dynamics of the organelle; whereas steroleosin proteins are also present in mammals and play an important role in steroid hormone metabolism and signaling. Significant progress using new genetic, biochemical, and imaging technologies has uncovered the roles of these proteins. Here, we review recent work on the structural or metabolic roles of these proteins in OB biogenesis, stabilization and degradation, lipid homeostasis and mobilization, hormone signal transduction, stress defenses, and various aspects of plant growth and development.

The Triacylglycerol Profile of Oil Bodies and Oil Extracted from Argania spinosa Using the UPLC Along with the Electrospray Ionization Quadrupole-Time-of-Flight Mass Spectrometry (LC-Q-TOF-MS).

The triacylglycerol (TAG) matrix of argan oil (AO) bodies (AOB) along with the TAGs of AO extracted from the same kernels using an organic solvent, were identified and quantified using the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Generally, both samples showed a similar TAGs profile but AO found to have three extra TAGs in low amount. In total 23 and 26 different TAGs were identified in AOBs and AO, respectively. The most abundant TAGs were OOL, POO, OOO, and POL in both samples. Furthermore, oleic acid, linoleic acid, and palmitic acid were the major fatty acids in both AOBs and AO. To the best of our knowledge, this is the first research that studied the TAGs matrix of an oil body revealing no major difference between the TAGs profile protected by the AOBs membrane and the oil extracted from the whole seed. PRACTICAL APPLICATION: Seed and kernels oil bodies emulsion tend to be the new source of emulsified oil in food and cosmetic industries. However, before replacing a product with another, we have to make sure that the new alternative can offer better or at least similar benefits. Our results showed that the triacylglycerols (TAGs) matrix and the argan oil (AO) share the same TAGs profile with a relatively close percentage. Therefore, AO bodies can be the perfect pre-emulsified oil for some food products like sauces and creams.

Comparative RNA-Seq Analysis of High- and Low-Oil Yellow Horn During Embryonic Development

Yellow horn (Xanthoceras sorbifolium Bunge) is an endemic oil-rich shrub that has been widely cultivated in northern China for bioactive oil production. However, little is known regarding the molecular mechanisms that contribute to oil content in yellow horn. Herein, we measured the oil contents of high- and low-oil yellow horn embryo tissues at four developmental stages and investigated the global gene expression profiles through RNA-seq. The results found that at 40, 54, 68, and 81 days after anthesis, a total of 762, 664, 599, and 124 genes, respectively, were significantly differentially expressed between the high- and low-oil lines. Gene ontology (GO) enrichment analysis revealed some critical GO terms related to oil accumulation, including acyl-[acyl-carrier-protein] desaturase activity, pyruvate kinase activity, acetyl-CoA carboxylase activity, and seed oil body biogenesis. The identified differentially expressed genes also included several transcription factors, such as, AP2-EREBP family members, B3 domain proteins and C2C2-Dof proteins. Several genes involved in fatty acid (FA) biosynthesis, glycolysis/gluconeogenesis, and pyruvate metabolism were also up-regulated in the high-oil line at different developmental stages. Our findings indicate that the higher oil accumulation in high-oil yellow horn could be mostly driven by increased FA biosynthesis and carbon supply, i.e. a source effect.

Expression of a functional recombinant vascular endothelial growth factor 165 (VEGF165) in Arabidopsis thaliana

Abstract Objective Targeting the protein of interest to a particular tissue to achieve high-level expression is an important strategy to increase expression efficiency. The use of the plant seed oil body as a bioreactor can not only increase the amount of target protein, but also reduce the cost of downstream processing. Methods VEGF165 was expressed in Arabidopsis thaliana seeds via oilbody fusion technology. The pKO-VEGF165 vector was construted and transformed into A. thaliana seeds. T3 transgenic seeds was detected by SDS-PAGE and western blot methods. The cell activity was tested by MTT methods. Result The phaseolin promoter was used to drive seed-specific expression of the VEGF 165 gene in transgenic A. thaliana. The coding region of VEGF 165 was fused to the Arabidopsis oleosin sequence to target the protein to the oil bodies in the seeds of transgenic plants. The T-DNA region of recombinant plasmid pKO-VEGF165 was shifted to A. thaliana seeds via the floral-dip method. Protein was analyzed by electrophoresis and protein hybridization analyses. Finally, MTT assays showed that the oleosin-VEGF165 fusion protein played a part in the proliferation of HUVEC cells in vitro. Conclusion Oleosin-VEGF165 was successfully expressed and it had stimulated HUVEC cell proliferation activity.

Expression of oleosin-rhFGF9 fusion protein in Carthamus tinctorius and determination of hair regeneration and wound repair potential in mice

The expression of fibroblast growth factor 9 (FGF9) recombinant fusion protein in Carthamus tinctorius was used to identify its effect on hair regrowth and wound repair system in mice, providing a basis for C. tinctorius as a plant bioreactor, and establishing a foundation for commercial applications of FGF9 fusion protein in hair regrowth and wound repair. The identified pOTBar-oleosin-rhFGF9 plasmid was transformed into Agrobacterium tumefaciens EHA105 by freeze-thaw method, and the oleosin-rhFGF9 gene was transformed into safflower leaves by A. tumefaciens mediated method. Transgenic safflower seedlings were then obtained by tissue culture. After basta screening, transgenic T₃ safflower seeds were obtained by grafting method, PCR verification and propagation. The expression of oleosin-rhFGF9 was detected by Western blot, and the content of oleosin-rhFGF9 fusion protein was 0.09% by using ELISA quantitative method. It was observed that 60 μg·L⁻¹ transgenic safflower oil had better effect on promoting NIH/3T3 cells proliferation in a certain dose-dependent manner. Sixty C57BL/6 mice were used to establish alopecia model and wound model respectively, and then were randomly divided into control group (treated with PBS or saline), negative group (treated with wild type safflower seed oil bodies, 60 g·L⁻¹), positive group (treated with FGF9, 0.054 g·L⁻¹), low dose group (treated with transgenic safflower oil bodies, 10 g·L⁻¹) and high dose group (treated with transgenic safflower oil bodies, 60 g·L⁻¹). The skin of all above-mentioned mice models were coated with soft adhesive manner every other day, 100 μL/time. After 15 days, the mice skin was cut and embedded for histological analysis. The hair regrowth experimental results showed that the hair of mice grew well, and the mice in high dose group had bushy hair, with significant effect on regeneration hair number as compared with the positive group. The healing was obvious in wound experiment, with significant healing effect in positive group, high dose group and low dose group as compared to blank control group. Furthermore, high dose group remarkably showed a better and higher healing effect than the positive group at day 5. Oleosin-rhFGF9 was successfully transformed into safflower, and T₃ transgenic safflower oil bodies expressed oleosin-rhFGF9 fusion protein were obtained, with the role of promoting hair regeneration and wound repair in mice.