High accumulation of γ-linolenic acid and Stearidonic acid in transgenic Perilla (Perilla frutescens var. frutescens) seeds

Crucial amino acids identified in Δ12 fatty acid desaturases related to linoleic acid production in Perilla frutescens

Perilla oil from the medicinal crop Perilla frutescens possess a wide range of biological activities and is generally used as an edible oil in many countries. The molecular basis for its formation is of particular relevance to perilla and its breeders. Here in the present study, four PfFAD2 genes were identified in different perilla cultivars, PF40 and PF70, with distinct oil content levels, respectively. Their function was characterized in engineered yeast strain, and among them, PfFAD2-1PF40, PfFAD2-1PF70 had no LA biosynthesis ability, while PfFAD2-2PF40 in cultivar with high oil content levels possessed higher catalytic activity than PfFAD2-2PF70. Key amino acid residues responsible for the enhanced catalytic activity of PfFAD2-2PF40 was identified as residue R221 through sequence alignment, molecular docking, and site-directed mutation studies. Moreover, another four amino acid residues influencing PfFAD2 catalytic activity were discovered through random mutation analysis. This study lays a theoretical foundation for the genetic improvement of high-oil-content perilla cultivars and the biosynthesis of LA and its derivatives.

The metabolomics analysis of cecal contents elucidates significant metabolites involved in the therapeutic effects of total flavonoids derived from Sonchus arvensis L. in male C57BL/6 mice with ulcerative colitis

Ulcerative colitis (UC), an inflammatory disease affecting the colon and rectal mucosa, is characterized by chronic and heterogeneous behavior of unknown origin. The primary cause of UC is chronic inflammation, which is closely linked to the development of colorectal cancer. Sonchus arvensis L. (SAL), a plant consumed worldwide for its nutritional and medicinal properties, holds significance in this context. In this study, we employed the total flavone in SAL as a treatment for male C57BL/6 mice with UC. The cecal contents metabolic profile of C57BL/6 mice in different groups, including UC (group ML; n = 5), UC treated with aspirin (group AN; n = 5), UC treated with the total flavone in SAL (group FE; n = 5), and healthy male C57BL/6 mice (group CL; n = 5), was examined using UHPLC-Triple-TOF-MS. Through the identification of variations in key metabolites associated with UC and the exploration of their underlying biological mechanisms, our understanding of the pathological processes underlying this condition has been enhanced. This study identified a total of seventy-three metabolites that have a significant impact on UC. Notably, the composition of total flavone in SAL, a medication used for UC treatment, differs from that of aspirin due to the presence of four distinct metabolites (13,14-Dihydro-15-keto-PGE2, Prostaglandin I2 (PGI2), (20R,22R)-20,22-dihydroxycholesterol, and PS (18:1(9Z)/0:0)). These metabolites possess unique characteristics that set them apart. Moreover, the study identified a total of eleven pathways that were significantly enriched in mice with UC, including Aminoacyl-tRNA biosynthesis, Valine, leucine and isoleucine biosynthesis, Linoleic acid metabolism, PPAR signaling pathway, mTOR signaling pathway, Valine, leucine and isoleucine degradation, Lysine degradation, VEGF signaling pathway, Melanogenesis, Endocrine and other factor-regulated calcium reabsorption, and Cocaine addiction. These findings contribute to a better understanding of the metabolic variations in UC following total flavonoids of SAL therapy and provide valuable insights for the treatment of UC.Keywords: Ulcerative colitis; Total flavonoids of Sonchus arvensis L.; Key metabolites; Metabonomics; Cecal contents of male C57BL/6 mice.

Integrative physiological, transcriptomic, and metabolomic analysis of Abelmoschus manihot in response to Cd toxicity

Rapid industrialization and urbanization have caused severe soil contamination with cadmium (Cd) necessitating effective remediation strategies. Phytoremediation is a widely adopted technology for remediating Cd-contaminated soil. Previous studies have shown that Abelmoschus manihot has a high Cd accumulation capacity and tolerance indicating its potential for Cd soil remediation. However, the mechanisms underlying its response to Cd stress remain unclear. In this study, physiological, transcriptomic, and metabolomic analyses were conducted to explore the response of A. manihot roots to Cd stress at different time points. The results revealed that Cd stress significantly increased malondialdehyde (MDA) levels in A. manihot, which simultaneously activated its antioxidant defense system, enhancing the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) by 19.73%-50%, 22.87%-38.89%, and 32.31%-45.40% at 12 h, 36 h, 72 h, and 7 days, respectively, compared with those in the control (CK). Moreover, transcriptomic and metabolomic analyses revealed 245, 5,708, 9,834, and 2,323 differentially expressed genes (DEGs), along with 66, 62, 156, and 90 differentially expressed metabolites (DEMs) at 12 h, 36 h, 72 h, and 7 days, respectively. Through weighted gene coexpression network analysis (WGCNA) of physiological indicators and transcript expression, eight hub genes involved in phenylpropanoid biosynthesis, signal transduction, and metal transport were identified. In addition, integrative analyses of metabolomic and transcriptomic data highlighted the activation of lipid metabolism and phenylpropanoid biosynthesis pathways under Cd stress suggesting that these pathways play crucial roles in the detoxification process and in enhancing Cd tolerance in A. manihot. This comprehensive study provides detailed insights into the response mechanisms of A. manihot to Cd toxicity.

Integrated analysis of miRNA, transcriptome, and degradome sequencing provides new insights into lipid metabolism in perilla seed

MicroRNAs (miRNA) are small noncoding RNAs that play a crucial as molecular regulators in lipid metabolism in various oil crops. Perilla (Perilla frutescens) is a specific oil crop known for its high alpha-linolenic acid (C18:3n3, ALA) content (>65 %) in their seed oils. In view of the regulatory mechanism of miRNAs in perilla remains unclear, we conducted miRNAs and transcriptome sequencing in two cultivars with distinct lipid compositions. A total of 525 unique miRNAs, including 142 differentially expressed miRNAs was identified in perilla seeds. The 318 miRNAs targeted 7,761 genes. Furthermore, we identified 112 regulated miRNAs and their 610 target genes involved in lipid metabolism. MiR159b and miR167a as the core nodes to regulate the expression of genes in oil biosynthesis (e.g., KAS, FATB, GPAT, FAD, DGK, LPAAT) and key regulatory TFs (e.g., MYB, ARF, DOF, SPL, NAC, TCP, and bHLH). The 1,219 miRNA-mRNA regulation modules were confirmed through degradome sequencing. Notably, pf-miR159b-MYBs and pf-miR167a-ARFs regulation modules were confirmed. They exhibited significantly different expression levels in two cultivars and believed to play important roles in oil biosynthesis in perilla seeds. This provides valuable insights into the functional analysis of miRNA-regulated lipid metabolism in perilla seeds.

Promising Sources of Plant-Derived Polyunsaturated Fatty Acids: A Narrative Review

(1) Background: Polyunsaturated fatty acids (PUFAs) are known for their ability to protect against numerous metabolic disorders. The consumption of oily fish is the main source of PUFAs in human nutrition and is commonly used for supplement production. However, seafood is an overexploited source that cannot be guaranteed to cover the global demands. Furthermore, it is not consumed by everyone for ecological, economic, ethical, geographical and taste reasons. The growing demand for natural dietary sources of PUFAs suggests that current nutritional sources are insufficient to meet global needs, and less and less will be. Therefore, it is crucial to find sustainable sources that are acceptable to all, meeting the world population's needs. (2) Scope: This review aims to evaluate the recent evidence about alternative plant sources of essential fatty acids, focusing on long-chain omega-3 (n-3) PUFAs. (3) Method: A structured search was performed on the PubMed search engine to select available human data from interventional studies using omega-3 fatty acids of non-animal origin. (4) Results: Several promising sources have emerged from the literature, such as algae, microorganisms, plants rich in stearidonic acid and GM plants. However, the costs, acceptance and adequate formulation deserve further investigation.

Solid-state fermentation produces greater stearidonic acid levels in genetically engineered Mucor circinelloides

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are important dietary components due to their health benefits and preventative role in cardiovascular disease. Fish-based and plant seed oils are rich in stearidonic acid (SDA; 18:4 n-3) which are readily metabolized into ω-3 PUFAs such as eicosapentaenoic acid. However, these natural sources of SDA are generally low yielding and are unlikely to meet global demands, so new sustainable microbial fermentative sources of SDA need to be identified. Expression of delta15-desaturase in the oleaginous filamentous fungus Mucor circinelloides (McD15D) has been used to construct a recombinant SDA-producing McD15D strain that produces 5.0% SDA levels using submerged fermentation conditions. Switching to solid-state fermentation conditions in the same medium with submerged fermentation resulted in this engineered strain producing significantly higher amounts of SDA. A Box-Behnken design (BBD) of response surface methodology (RSM) approach has been used to identify optimal glucose and ammonium tartrate concentrations and temperature levels to maximize SDA production. The use of these optimal solid-state fermentation conditions resulted in the spores and mycelium of the recombinant McD15D producing 19.5% (0.64 mg g^-1 ) and 12.2% (1.52 mg g^-1 ) SDA content respectively, which represents an overall increase in SDA yield of 188.0% when compared to SDA yields produced using submerged fermentation conditions.

Preparation and characterization of nanoemulsions of curcumin and echium oil

The search for the plant origin bioactive compounds is increasing over animal origin compounds. Echium oil (EO) contains high amounts of plant based omega-3 fatty acids. Moreover, curcumin addition may increase the release of these omega-3 fatty acids during digestion. The study's objective is to determine the bioaccessibility of curcumin in simulated intestinal digestion conditions and the release behavior of fatty acids of echium oil from nanoemulsions. We prepared curcumin and EO nanoemulsions with a microfluidizer using two different concentrations of surfactant, Tween 80 (5% and 10%). Emulsion stability tests, antioxidant analysis, in vitro oil release and fatty acid composition assays were conducted. Results showed that curcumin-containing nanoemulsions provide higher radical scavenging activity than the EO nanoemulsions. In addition, in vitro bioaccessibility of curcumin after in vitro simulated intestinal digestion was calculated as 35.5%. Gas chromatography results of the digested nanoemulsions revealed that curcumin addition decreases oleic acid release while increasing stearidonic acid (SDA) release.

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Curcumin addition increased antioxidant activities of EO nanoemulsions.

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Curcumin incorporated nanoemulsions had significantly higher SDA content after in vitro digestion.

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In nanoemulsion form, in vitro curcumin bioaccessibility was 35.5%.

Integrative iTRAQ-based proteomic and transcriptomic analysis reveals the accumulation patterns of key metabolites associated with oil quality during seed ripening of Camellia oleifera

Camellia oleifera (C. oleifera) is one of the four major woody oil-bearing crops in the world and has relatively high ecological, economic, and medicinal value. Its seeds undergo a series of complex physiological and biochemical changes during ripening, which is mainly manifested as the accumulation and transformation of certain metabolites closely related to oil quality, especially flavonoids and fatty acids. To obtain new insights into the underlying molecular mechanisms, a parallel analysis of the transcriptome and proteome profiles of C. oleifera seeds at different maturity levels was conducted using RNA sequencing (RNA-seq) and isobaric tags for relative and absolute quantification (iTRAQ) complemented with gas chromatography-mass spectrometry (GC-MS) data. A total of 16,530 transcripts and 1228 proteins were recognized with significant differential abundances in pairwise comparisons of samples at various developmental stages. Among these, 317 were coexpressed with a poor correlation, and most were involved in metabolic processes, including fatty acid metabolism, α-linolenic acid metabolism, and glutathione metabolism. In addition, the content of total flavonoids decreased gradually with seed maturity, and the levels of fatty acids generally peaked at the fat accumulation stage; these results basically agreed with the regulation patterns of genes or proteins in the corresponding pathways. The expression levels of proteins annotated as upstream candidates of phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) as well as their cognate transcripts were positively correlated with the variation in the flavonoid content, while shikimate O-hydroxycinnamoyltransferase (HCT)-encoding genes had the opposite pattern. The increase in the abundance of proteins and mRNAs corresponding to alcohol dehydrogenase (ADH) was associated with a reduction in linoleic acid synthesis. Using weighted gene coexpression network analysis (WGCNA), we further identified six unique modules related to flavonoid, oil, and fatty acid anabolism that contained hub genes or proteins similar to transcription factors (TFs), such as MADS intervening keratin-like and C-terminal (MIKC_MADS), type-B authentic response regulator (ARR-B), and basic helix-loop-helix (bHLH). Finally, based on the known metabolic pathways and WGCNA combined with the correlation analysis, five coexpressed transcripts and proteins composed of cinnamyl-alcohol dehydrogenases (CADs), caffeic acid 3-O-methyltransferase (COMT), flavonol synthase (FLS), and 4-coumarate: CoA ligase (4CL) were screened out. With this exploratory multiomics dataset, our results presented a dynamic picture regarding the maturation process of C. oleifera seeds on Hainan Island, not only revealing the temporal specific expression of key candidate genes and proteins but also providing a scientific basis for the genetic improvement of this tree species.

Assessment of genetic diversity and population structure among a collection of Korean Perilla germplasms based on SSR markers

BACKGROUND

Information on the genetic variation of genetic resource collections is very important for both the conservation and utilization of crop germplasms in genebanks. Var. frutescens of Perilla crop is extensively cultivated in South Korea as both an oil crop and a vegetable crop.

OBJECTIVES

We used SSR markers to evaluate the genetic diversity, genetic relationships, and population structure of 155 accessions of var. frutescens that have been selected as genetic resources for the development of leaf vegetable cultivars and preserved in the RDA-Genebank collection from South Korea.

METHODS

A total of 155 accessions of var. frutescens of Perilla crop collected in South Korea were obtained from the RDA-Genebank of the Republic of Korea. We selected 20 SSR markers representing the polymorphism of and adequately amplifying all the Perilla accessions.

RESULTS

The average GD and PIC values were 0.642 and 0.592, respectively, with ranges of 0.244-0.935 and 0.232- 0.931. The genetic variability in the southern region of South Korea was higher than that in the central region. The clustering patterns were not clearly distinguished between the accessions of var. frutescens from the central and southern regions of South Korea.

CONCLUSION

These results regarding the genetic diversity and population structure of the 155 accessions of var. frutescens of South Korea provide useful information for understanding the genetic variability of this crop and selecting and managing core germplasm sets in the RDA-Genebank of the Republic of Korea.

Metabolite Profiling and Chemometric Study for the Discrimination Analyses of Geographic Origin of Perilla (Perilla frutescens) and Sesame (Sesamum indicum) Seeds

Perilla and sesame are traditional sources of edible oils in Asian and African countries. In addition, perilla and sesame seeds are rich sources of health-promoting compounds, such as fatty acids, tocopherols, phytosterols and policosanols. Thus, developing a method to determine the geographic origin of these seeds is important for ensuring authenticity, safety and traceability and to prevent cheating. We aimed to develop a discriminatory predictive model for determining the geographic origin of perilla and sesame seeds using comprehensive metabolite profiling coupled with chemometrics. The orthogonal partial least squares-discriminant analysis models were well established with good validation values (Q² = 0.761 to 0.799). Perilla and sesame seed samples used in this study showed a clear separation between Korea and China as geographic origins in our predictive models. We found that glycolic acid could be a potential biomarker for perilla seeds and proline and glycine for sesame seeds. Our findings provide a comprehensive quality assessment of perilla and sesame seeds. We believe that our models can be used for regional authentication of perilla and sesame seeds cultivated in diverse geographic regions.

Plant-based stearidonic acid as sustainable source of omega-3 fatty acid with functional outcomes on human health

Dietary omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) like eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are known to be potent biological regulators with therapeutic and preventive effects on human health. Many global health organizations have recommended consuming marine based omega-3 sources for neonatal brain development and reducing the risk of various chronic diseases. However, due to concerns regarding the origin, sustainable supply and safety of the marine sources, alternative n-3 PUFA sources are being explored. Recently, plant-based omega-3 sources are gaining much importance because of their sustainable supply and dietary acceptance. α-linolenic acid (ALA, 18:3n-3) rich seed oils are the major omega-3 fatty acid source available for human consumption. But, efficiency of conversion of ALA to n-3 LC-PUFAs in humans is limited due to a rate-limiting step in the n-3 pathway catalyzed by Δ6-desaturase. Botanical stearidonic acid (SDA, 18:4n-3) rich oils are emerging as a sustainable omega-3 source with efficient conversion rate to n-3 LC-PUFA especially to EPA, as it bypasses the Δ6-desaturase rate limiting step. Several recent studies have identified the major plant sources of SDA and explored its potential health benefits and preventive roles in inflammation, cardiovascular disease (CVD) and cancer. This systematic review summarizes the current state of knowledge on the sources, nutraceutical roles, food-based applications and the future perspectives of botanical SDA.

Calanus oil in the treatment of obesity-related low-grade inflammation, insulin resistance, and atherosclerosis

Calanus oil (COil) is a natural product extracted from marine zooplankton Calanus finmarchicus found in the North Atlantic Ocean. This oil is rich in wax esters of polyunsaturated fatty acids (PUFAs) and has been projected as the best alternative to fish oil because its production cannot keep pace with the demands from the growing markets. The COil is the only commercially available marine source of wax esters, whereas classic ω-3 PUFAs comes from triglycerides, ethyl esters, and phospholipids. It has, in recent decades, been seen that there is an unprecedented rise in the use of PUFA-rich oil in the aquaculture industry. A simultaneous rise in the demand of PUFAs is also observed in the health care industry, where PUFAs are suggested preventing various disorders related to lifestyles such as obesity, diabetes mellitus, chronic low-grade inflammation, atherosclerosis, and brain and cardiovascular disorders (CVDs). In this review, we will explore the metabolic aspects related to the use of COil as an antioxidant, anticholesterinemic, and anti-inflammatory dietary source and its impact on the prevention and therapy of obesity-related metabolic disorders.