Chemical characterization of winged bean (Psophocarpus tetragonolobus (L.) DC. seeds and safety evaluation of its fatty oil

Elucidating the Secondary Metabolite Biosynthesis Networks in Underutilized Tree Bean (Parkia timoriana) Through Integrated Metabolomic and Transcriptomic Approaches

The tree bean (Parkia timoriana (DC). Merr) is an underutilized legume and is abundantly found in Southeast Asia. It is valued for its nutritious pods and cultivated for food and timber. Despite of the presence of several nutrients, the regulatory networks involved in secondary metabolite biosynthesis in the tree bean remain largely unexplored. Recent studies have highlighted that consumption of its pods provides numerous health benefits, including antioxidant, α-glucosidase inhibitory, antibacterial, antidiabetic, and insecticidal activities. To elucidate the biosynthesis of specific metabolites in this plant, a comparative metabolite and transcriptomic analysis of the leaf and root tissues of P. timoriana was carried out. The study revealed that P. timoriana leaf and root tissues contain varying levels of phenolics, flavonoids, and terpenoids. 1H nuclear magnetic resonance (1H NMR) analysis identified 16 significant metabolites in the leaf and root tissues, including sugars, amino acids, and organic acids. L-dihydroxyphenylalanine (L-DOPA), an amino acid derivative and precursor to dopamine, was detected for the first time in the seeds. Additionally, the presence of pinitol in P. timoriana was also confirmed. De novo RNA-sequence analysis identified differentially expressed genes (DEGs) in both the tissues. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis identified pathways associated with shikimate pathway, such as phenylpropanoid and flavonoid biosynthesis. MapMan pathway analysis revealed a high number of transcripts related to phenylalanine, tryptophan, tyrosine, and condensed tannin biosynthesis. The research conducted identified secondary metabolites in P. timoriana, and their probable biosynthetic pathway which can be used for medicinal and nutritional purposes.

Biotransformation of ricinoleic acid to γ-decalactone using novel yeast strains and process optimization by applying Taguchi model

Flavour molecules are generated now-a-days through microbial fermentation on a commercial scale. γ-Decalactone (GDL) is an important molecule due to its long-lasting flavouring impact as buttery, coconut and peach-type. In the current study, 33 microorganisms were isolated from different fruit sources, and their screening for target GDL production was performed. Using DNA sequencing, two potential strains yielding good amounts of GDL were identified from pineapple and strawberry fruits. The identified strains were Metschnikowia vanudenii (OP954735) and Candida parapsilosis (OP954733), and further optimized by Taguchi method. The effectiveness of lactone production is influenced by the rate of microbial growth under various operating conditions. The factors such as substrate concentration, pH, temperature, cell density and rotation (rpm) with 3 levels were applied for the GDL production using M. vanudenii (OP954735) and C. parapsilosis (OP954733) strains. The results revealed that the highest molar conversion of GDL was 24.69% (115.7 mg/g quantitative yield) and 52.69% (272.0 mg/g quantitative yield) at the optimal conditions using SB-62 and PA-19 strains, respectively. The two novel strains are reported for the first time for production of γ-decalactone and overall, this study opens up the possibility of using Taguchi design for large scale up process development for producing food flavours utilising environmentally friendly natural strains.

Underutilized legumes: nutrient status and advanced breeding approaches for qualitative and quantitative enhancement

Underutilized/orphan legumes provide food and nutritional security to resource-poor rural populations during periods of drought and extreme hunger, thus, saving millions of lives. The Leguminaceae, which is the third largest flowering plant family, has approximately 650 genera and 20,000 species and are distributed globally. There are various protein-rich accessible and edible legumes, such as soybean, cowpea, and others; nevertheless, their consumption rate is far higher than production, owing to ever-increasing demand. The growing global urge to switch from an animal-based protein diet to a vegetarian-based protein diet has also accelerated their demand. In this context, underutilized legumes offer significant potential for food security, nutritional requirements, and agricultural development. Many of the known legumes like Mucuna spp., Canavalia spp., Sesbania spp., Phaseolus spp., and others are reported to contain comparable amounts of protein, essential amino acids, polyunsaturated fatty acids (PUFAs), dietary fiber, essential minerals and vitamins along with other bioactive compounds. Keeping this in mind, the current review focuses on the potential of discovering underutilized legumes as a source of food, feed and pharmaceutically valuable chemicals, in order to provide baseline data for addressing malnutrition-related problems and sustaining pulse needs across the globe. There is a scarcity of information about underutilized legumes and is restricted to specific geographical zones with local or traditional significance. Around 700 genera and 20,000 species remain for domestication, improvement, and mainstreaming. Significant efforts in research, breeding, and development are required to transform existing local landraces of carefully selected, promising crops into types with broad adaptability and economic viability. Different breeding efforts and the use of biotechnological methods such as micro-propagation, molecular markers research and genetic transformation for the development of underutilized crops are offered to popularize lesser-known legume crops and help farmers diversify their agricultural systems and boost their profitability.

Reducing the biosynthesis of condensed tannin in winged bean (Psophocarpus tetragonolobus (L.) DC.) by virus-induced gene silencing of anthocyanidin synthase (ANS) gene

The Underutilized legume-winged bean (Psophocarpus tetragonolobus (L.) DC.) and its various parts are infested with condensed tannin (CT) or proanthocyanidin (PA). CT has anti-nutritional effect as it adversely affects the digestion of proteins, minerals and vitamin among ruminants and humans. It is also responsible for low protein digestibility and decreased amino acid availability. One of the probable reasons of underutilization of P. tetragonolobus is due to its infestation with CT. Histochemical staining of various tissues of P. tetragonolobus with dimethylcinnmaldehyde (DMACA) developed a deep-blue colour indicating the presence of polyphenolic condensed tannin. Structural monomeric unit catechin and epi-catechin were reported to be responsible for biosynthesis of CT in P. tetragonolobus. The enzyme anthocyanidin synthase (ANS) and its corresponding transcripts were identified and phylogenetically mapped. The transcript was subjected to virus-induced gene silencing (VIGS) through agro-infiltration in P. tetragonolobus for reducing the CT-content. The WbANS-VIGS induced P. tetragonolobus resulted in four-fold decrease of CT as compared to the control P. tetragonolobus. A decrease of 73% of CT level was reported in VIGS silenced Wb-ANS line of P. tetragonolobus. This study resulted and confirmed that, the silencing of (ANS) gene in P. tetragonolobus has a regulatory effect on the condensed tannin biosynthesis. This study will pave way for further manipulation of ANS enzyme for reducing the biosynthesis of the anti-nutrient CT. Reducing the CT content will make this underutilized legume more acceptable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03435-5.