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.

Physico-chemical Characterization, Profiling of Total Lipids and Triacylglycerol Molecular Species of Omega-3 Fatty Acid Rich B. arvensis Seed Oil from India.

Buglossoides arvensis is indigenous to India and its seed oil is rich in unique and nutritionally important omega-3 fatty acid namely, stearidonic acid (SDA). It is a non-conventional oil seed plant and needs to be agronomically adapt for commercial utilization. In the present study, oil extracted from the agronomically adapted high yielding cultivar of B. arvensis seeds was analyzed for its oil content, fatty acid (FA) composition, physico-chemical characteristics, total lipids and triacylglycerol molecular species. The oil content, peroxide, acid, iodine, p-anisidine values and tocopherol content of the oil were 18.53% (w/w), 2.06 meq of active oxygen / kg of oil, 2.55 mg KOH/g oil, 217.2 g I2/100g oil, 10.7 and 774.8 mg/kg oil respectively. Oxidative stability as determined by the induction period was found to be 3.1 h. Polyunsaturated fatty acid (PUFA) content of the oil was 81.3% (of total FA), comprising of α-linolenic acid (ALA; 48.5%), SDA (18.6%), linoleic acid (LA; 10.3%) and γ-linolenic acid (GLA; 3.9%). Profiling of lipid classes showed neutral lipids (89.3%, w/w) as most abundant lipid class followed by glycolipids (7.4%, w/w) and phospholipids (3.3%, w/w). High resolution mass spectrometric analysis of triacylglycerol (TAG) molecular species showed TAGs with C54 carbons in the acyl chain as most abundant. Positional distribution analysis showed GLA and SDA predominantly at the sn-2 position of triacylglycerol. FTIR analysis revealed common characteristics molecular features similar to PUFA rich oils. Overall, the results suggest that B. arvensis seed oil is an excellent ω3-ω6-ω3 or ALA-SDA-GLA source for food and nutraceutical industries.

Unravelling a stearidonic acid-rich triacylglycerol biosynthetic pathway in the developing seeds of Buglossoides arvensis: A transcriptomic landscape.

Buglossoides arvensis is an emerging oilseed crop that is rich in stearidonic acid (SDA) and has several potential applications in human health and nutrition. The molecular basis of SDA biosynthesis in this plant remains unknown due to lack of genomic information. To unravel key genes involved in SDA-rich triacylglycerol (TAG) biosynthesis, we performed transcriptome sequencing of pooled mRNA from five different developmental stages of B. arvensis seeds using Illumina NextSeq platform. De novo transcriptome assembly generated 102,888 clustered transcripts from 39.83 million high-quality reads. Of these, 62.1% and 55.54% of transcripts were functionally annotated using Uniprot-Viridiplantae and KOG databases, respectively. A total of 10,021 SSR-containing sequences were identified using the MISA tool. Deep mining of transcriptome assembly using in silico tools led to the identification of genes involved in fatty acid and TAG biosynthesis. Expression profiling of 17 key transcripts involved in fatty acid desaturation and TAG biosynthesis showed expression patterns specific to the development stage that positively correlated with polyunsaturated fatty acid accumulation in the developing seeds. This first comprehensive transcriptome analysis provides the basis for future research on understanding molecular mechanisms of SDA-rich TAG accumulation in B. arvensis and aids in biotechnological production of SDA in other oilseed crops.

The use of genetic markers for detecting DNA polymorphism, genotype identification and phylogenetic relationships among banana cultivars.

Genetic variations and relationships among 21 commercially important banana cultivars of South India were evaluated using 50 decamer RAPD primers and 12 ISSR primers. The primers were selected after a preliminary screening of several such primers for their ability to produce clear and reproducible patterns of multiple bands. The analyses resulted in the amplification of totally 641 bands of 200-3100bp, of which 382 bands were polymorphic, corresponding to nearly 60% genetic diversity. The RAPD and ISSR surveys between pairs of 21 cultivars revealed 60.15% and 56.73% of polymorphic bands, respectively. A strong linear relationship was observed between the Resolving power (Rp) of the primer and its ability to distinguish genotypes. Based on these data, a genetic similarity matrix was established and a dendrogram for each set of primers was developed by UPGMA. The genetic similarity coefficients in RAPD analysis ranged from 0.3177 to 0.7818 and in ISSR analysis from 0.1800 to 0.8462. A fingerprinting key was generated where the presence/absence of specific RAPD/ISSR bands were recorded for each cultivar. The presence of a specific RAPD (OPC-5(800)) band was observed for an endemic cultivar--Nanjanagudu Rasabale (NR). The study resulted in the identification and molecular classification of South Indian banana cultivars of which Robusta and Williams are global and others have either limited geographical distribution or purely endemic to South India. A group of eight cultivars was identified that are highly distinct from one another. The members of this group may be useful for generating 2X and 4X breeding populations for further use in breeding secondary triploid hybrids.

Specific pretreatments reduce curing period of vanilla (Vanilla planifolia) beans.

With the aiming of reducing the curing period, effects of pretreatments on flavor formation in vanilla beans during accelerated curing at 38 degrees C for 40 days were studied. Moisture loss, change in texture, levels of flavoring compounds, and activities of relevant enzymes were compared among various pretreatments as well as the commercial sample. Use of naphthalene acetic acid (NAA; 5 mg/L) or Ethrel (1%) with blanching pretreatment resulted in 3-fold higher vanillin on the 10th day. Other flavoring compounds-vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde-fluctuated greatly, showing no correlation with the pretreatments. Scarification of beans resulted in nearly 4- and 3.6-fold higher vanillin formations on the 10th day in NAA- and Ethrel-treated beans, respectively, as compared to control with a significant change in texture. When activities of major relevant enzymes were followed, addition of NAA or Ethrel helped to retain higher levels of cellulase throughout the curing period and higher levels of beta-glucosidase on the 20th day that correlated with higher vanillin content during curing and subsequent periods. Peroxidase, being highest throughout, did not correlate with the change in levels of major flavoring compounds. The pretreatment methods of the present study may find importance for realizing higher flavor formation in a shorter period because the major quality parameters were found to be comparable to those of a commercial sample.

Nutraceutical applications of garlic and the intervention of biotechnology.

Garlic (Allium sativum L.) is an important and widely cultivated plant with both culinary and medicinal uses stemming from its biological activities, which include antibiotic, anticancer, anti-thrombotic, and lipid-lowering cardiovascular effects. Though such medicinal use of garlic existed for centuries, there was little scientific support for its therapeutic and pharmacological properties. However, there has been a recent upsurge of research on garlic aiming to understand its exact mechanism of action in each case so that garlic and its products may have more judicious future applications. Since garlic is vegetatively propagated, its improvement for desired traits through conventional means is difficult. The intervention of biotechnological methods such as tissue culture and gene transfer protocols developed recently hold great promise for improving this crop. Due to new innovations in instrumentation and processing technologies coupled with more judicious experimental models, better products are foreseen in the market. The objective of this article was to review the recent developments made towards understanding the mechanism by which garlic imparts different therapeutic effects as well as to review what biotechnology can offer to improve this crop and its products.