BackgroundHimalayan plants are widely used in traditional system of medicine both as prophylactics and therapeutics for high altitude maladies. Our aim was to evaluate the antioxidant capacities and bioactive compounds of methanol and n-hexane extracts of the phytococktail comprising of sea buckthorn (Hippophae rhamnoides), apricot (Prunus armeniaca) and roseroot (Rhodiola imbricata) from trans-Himalaya.MethodsThe 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and nitric oxide (NO) radical scavenging capacities and lipid peroxidation inhibition (LPI) property of the extracts were determined. Total antioxidant power was determined by ferric reducing/antioxidant power (FRAP) assay. Total polyphenol, flavonoid, flavonol, proanthocyanidin and carotenoid were also estimated for both extracts. We have identified and quantified the phyto-chemotypes present in the methanol and n-hexane extracts by hyphenated gas chromatography/mass spectrometry (GC/MS) technique.ResultsAntioxidant capacity assays using DPPH, ABTS, NO, LPI and FRAP exhibited analogous results where the phytococktail showed high antioxidant action. The phytococktail was also found to possess high quantity of total polyphenol, flavonoid, flavonol and carotenoid. A significant and linear correlation was found between the antioxidant capacities and bioactive principles. A total of 32 phyto-chemotypes were identified from these extracts by GC/MS chemometric fingerprinting. Major phyto-chemotypes identified by GC/MS were glycosides, phenylpropanoids and derivatives, terpenoids, alkaloids, phytosterols, fatty acids and esters, alkaloids and derivatives, organic acid esters and aromatic ethers with positive biological and pharmacological actions.ConclusionThe phytococktail extracts were found to contain considerable amount of diverse bioactive compounds with high antioxidant capacities. The presence of hydrophilic and lipophilic antioxidants in the phytococktail could have contributed to the higher antioxidant values. Hence, the phytococktail could be used as natural source of antioxidants to ameliorate disorders associated with oxidative stress.

GTR1 and GTR2 transporters are components of the source to sink translocation network of glucosinolates, which are major defence metabolites in the Brassicaceae. These transporters can be genetically manipulated for reduction of seed-glucosinolates without inhibiting glucosinolate biosynthesis, thereby maintaining the inherent defence potential of plants. However, the different roles of GTRs in influencing tissue-specific distribution of glucosinolates in agriculturally important Brassica crops are yet unknown. Here, we report functional characterization of two groups of glucosinolate transporters (GTR1 and GTR2) from Brassica juncea based on gene expression data, biochemical analysis, gene-complementation studies in GTR-deficient mutants and RNAi-based knockdown followed by insect feeding experiments. Although both GTRs showed ubiquitous expression patterns and broad substrate specificity, the single-gene knockdown lines displayed different phenotypes. The GTR2-knockdown plants showed a significant reduction of glucosinolates in seeds and a higher accumulation in leaves and pods, while the GTR1-knockdown plants displayed a smaller reduction of glucosinolates in seeds and significantly lower glucosinolate levels in leaves. Consequently, knockdown of GTR2 resulted in higher resistance towards the generalist pest, Spodoptera litura. Overall, our study highlights the distinctive roles of B. juncea GTRs in tissue-specific accumulation of glucosinolates and the potential for manipulating GTR2 for enhanced nutrition and plant defence.

Sequence-related amplified polymorphism markers were used to assess the genetic structure in three natural populations of Morus alba from trans-Himalaya. Multilocation sampling was conducted across 14 collection sites. The overall genetic diversity estimates were high: percentage polymorphic loci 89.66%, Nei's gene diversity 0.2286, and Shannon's information index 0.2175. At a regional level, partitioning of variability assessed using analysis of molecular variance (AMOVA), revealed 80% variation within and 20% among collection sites. Pattern appeared in STRUCTURE, BARRIER, and AMOVA, clearly demonstrating gene flow between the Indus and Suru populations and a geographic barrier between the Indus-Suru and Nubra populations, which effectively hinders gene flow. The results showed significant genetic differentiation, population structure, high to restricted gene flow, and high genetic diversity. The assumption that samples collected from the three valleys represent three different populations does not hold true. The fragmentation present in trans-Himalaya was more natural and less anthropogenic.

Heterosis refers to the superior performance of F1 hybrids over their respective parental inbred lines. Although the genetic and expression basis of heterosis have been previously investigated, the metabolic basis for this phenomenon is poorly understood. In a preliminary morphological study in Brassica juncea, we observed significant heterosis at the 50% flowering stage, wherein both the growth and reproduction of F1 reciprocal hybrids were greater than that of their parents. To identify the possible metabolic causes or consequences of this heterosis, we carried out targeted LC-MS analysis of 48 primary (amino acids and sugars) and secondary metabolites (phytohormones, glucosinolates, flavonoids, and phenolic esters) in five developmental tissues at 50% flowering in hybrids and inbred parents. Principal component analysis (PCA) of metabolites clearly separated inbred lines from their hybrids, particularly in the bud tissues. In general, secondary metabolites displayed more negative heterosis values in comparison to primary metabolites. The tested primary and secondary metabolites displayed both additive and non-additive modes of inheritance in F1 hybrids, wherein the number of metabolites showing an additive mode of inheritance were higher in buds and siliques (52.77-97.14%) compared to leaf tissues (47.37-80%). Partial least regression (PLS) analysis further showed that primary metabolites, in general, displayed higher association with morphological parameters in F1 hybrids. Overall, our results are consistent with a resource-cost model for heterosis in B. juncea, where metabolite allocation in hybrids appears to favor growth, at the expense of secondary metabolism.

The aim of this study was to evaluate the in vitro antioxidant potential of hydro-ethanolic extract of a novel phytococktail comprising of sea buckthorn, apricot, and Rhodiola (SAR) from trans-Himalaya. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity of the extract increased in a dose-dependent manner (upto 0.1 mg/mL), and was found to be about 38% of that of ascorbic acid at 0.1 mg/mL. The hydro-ethanolic extract of SAR also scavenged the ABTS(.+) radical generated by ABTS/potassium persulfate (PPS) system and was found to be about 62% of that of ascorbic acid at 0.1 mg/ mL. The total antioxidant power of the extract was determined by ferric reducing antioxidant power (FRAP) assay. Total phenolic content was found to be 1.28016 × 10(-3) mol gallic acid equivalent (GAE)/g extract. Total flavonoid and flavonol contents were estimated to be 2.5970 × 10(-4) mol and 4.87 × 10(-4) mol quercetin equivalent/g extract, respectively. The hydro-ethanolic extract of this phytococktail indicated presence of essential phytoconstituents of polyphenols, flavonoids, flavonols, and ascorbic acid, which contributed significantly to its antioxidant capacity. The combination of the 3 plants may well support their use in traditional medicine to combat oxidative stress and high-altitude sickness.

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Immature seeds were cultured on 10 different media for germination. Maximum germination was achieved on Lindeman orchid medium (37.12%) within 17 days of culturing. Protocorms with leaf primordia were cultured on BM-2 and 7 different modifications of Murashige and Skoog (MS) medium with various hormone combinations [0-3 mg/L indole butyric acid (IBA) and 0-3 mg/L kinetin (Kin)] for plantlet regeneration and mass multiplication. Maximum number of shoots (18.12 ± 0.3), highest shoot length (17.80 cm ± 2.16), maximum root number (8.25 ± 0.69), and highest root length (8.02 cm ± 1.45) were found on MS medium with 3 mg/L IBA and 1 mg/L Kin. Plantlets with 2-3 shoots were transferred to different potting mixtures for acclimatization to field conditions and further multiplication. One hundred percent survival was obtained in C-8 potting mixture consisting of cocopeat + vermiculite + perlite (1:1:1), which produced 75 shoots (25 plantlets) after 1 month of transplantation in the greenhouse. The current study describes for the first time a rapid in vitro protocorm development and mass multiplication protocol for Dactylorhiza hatagirea (D.Don) Soo that holds robust potential for large-scale propagation and metabolite production.

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