Botanicals containing iridoid and phenylethanoid/phenylpropanoid glycosides are used worldwide for the treatment of inflammatory musculoskeletal conditions that are primary causes of human years lived with disability, such as arthritis and lower back pain.We report the analysis of candidate anti-inflammatory metabolites of several endemic Scrophularia species and Verbascum thapsus used medicinally by peoples of North America.Leaves, stems, and roots were analyzed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and partial least squares-discriminant analysis (PLS-DA) was performed in MetaboAnalyst 3.0 after processing the datasets in Progenesis QI.Comparison of the datasets revealed significant and differential accumulation of iridoid and phenylethanoid/phenylpropanoid glycosides in the tissues of the endemic Scrophularia species and Verbascum thapsus.Our investigation identified several species of pharmacological interest as good sources for harpagoside and other important anti-inflammatory metabolites.

Nutrient deprivation causes significant stress to the unicellular microalga, Chlamydomonas reinhardtii, which responds by significantly altering its metabolic program. Following N deprivation, the accumulation of starch and triacylglycerols (TAGs) is significantly altered following massive reprogramming of cellular metabolism. One protein that was found to change dramatically and early to this stress was TAB2, a photosystem I (PSI) translation initiation factor, whose transcript and protein levels increased significantly after only 30 min of N deprivation. A detailed physiological and omics-based analysis of an insertional mutant of Chlamydomonas with reduced TAB2 function was conducted to determine what role the functional PSI plays in regulating the cellular response to N deprivation.The tab2 mutant displayed increased acetate assimilation and elevated starch levels during the first 6 h of N deprivation, followed by a shift toward altered amino acid synthesis, reduced TAG content and altered fatty acid profiles. These results suggested a central role for PSI in controlling cellular metabolism and its implication in regulation of lipid/starch partitioning. Time course analyses of the tab2 mutant versus wild type under N-deprived versus N replete conditions revealed changes in the ATP/NADPH ratio and suggested that TAG biosynthesis may be associated with maintaining the redox state of the cell during N deprivation. The loss of ability to accumulate TAG in the tab2 mutant co-occurred with an up-regulation of photo-protective mechanisms, suggesting that the synthesis of TAG in the wild type occurs not only as a temporal energy sink, but also as a protective electron sink.By exploiting the tab2 mutation in the cells of C. reinhardtii cultured under autotrophic, mixotrophic, and heterotrophic conditions during nitrogen replete growth and for the first 8 days of nitrogen deprivation, we showed that TAG accumulation and lipid/starch partitioning are dynamically regulated by alterations in PSI function, which concomitantly alters the immediate ATP/NADPH demand. This occurs even without removal of nitrogen from the medium, but sufficient external carbon must nevertheless be available. Efforts to increase lipid accumulation in algae such as Chlamydomonas need to consider carefully how the energy balance of the cell is involved in or affected by such efforts and that numerous layers of metabolic and genetic regulatory control are likely to interfere with such efforts to control oil biosynthesis. Such knowledge will enable synthetic biology approaches to alter the response to the N depletion stress, leading to rewiring of the regulatory networks so that lipid accumulation could be turned on in the absence of N deprivation, allowing for the development of algal production strains with highly enhanced lipid accumulation profiles.

Lipophilic flavones with several methoxyl residues occur in various clades of land plants, from liverworts to core eudicots. Their chemodiversity is mediated by the manifold combinations of oxygenation and methoxylation patterns. In the Lamiaceae, Asteraceae, and Rutaceae, (poly)methoxylated flavones are thought to be produced by secretory tissues and stored externally or in oil cavities. They exhibit an array of bioactivities in vitro and in vivo, and may constitute part of the plants’ chemical defense mechanisms and represent promising natural lead molecules for the development of potent antiproliferative, antidiabetic, or anti-inflammatory drugs. The biosynthesis of (poly)methoxylated flavones in sweet basil (Ocimum basilicum L.) has been largely elucidated in the past few years. The knowledge obtained in those studies can be used for enzymatic semi-synthesis of these flavones as well as for further cell biological and physiological studies of basil trichome metabolism. In addition, these findings create an excellent starting point for investigations into (poly)methoxylated flavone metabolism in more and less distantly related taxa, which would shed light on the evolution of this biosynthetic capacity.

Turmeric (Curcuma longa L.) is a rhizomatous species belonging to the Zingiberaceae and known both for its culinary and medicinal uses. Based on an efficient tissue culture and somatic embryogenesis system that we established, we have developed a reliable Agrobacterium-mediated transformation protocol for this species. Calli derived from turmeric inflorescences were used as source tissues for transformation. Factors affecting transformation and regeneration efficiency were evaluated, including callus induction and culture conditions, Agrobacterium strains, co-cultivation conditions, selection agent sensitivity and bacterial elimination, and transformant selection. Optimized transformation conditions were identified, including: use of Agrobacterium strain EHA105 with plasmid pBISN1 for infection; a modified B5 medium system for callus induction, subculture, co-culture and selection; and MS media for transformant regeneration. Transgenic plants and their vegetative (clonal) progeny stably expressed the transgene as indicated by GUS assay, PCR and Southern blot analysis. In addition, a transient gene expression system was developed that involves Agrobacterium infiltration of young turmeric leaves followed by in vitro regeneration of plantlets. This approach established that a MADS-box-GFP fusion protein was localized to the nucleus of turmeric cells. The stable transformation and transient expression systems described herein offer opportunities for assaying gene function in turmeric and for improving turmeric properties.

•An hydroxycinnamoyl-CoA double bond reductase was identified from apple.•The recombinant reductase catalyzed the formation of dihydroxycinnamoyl-CoAs.•The reductase may play a crucial role in the biosynthesis of dihydrochalcones.The apple tree (Malus sp.) is an agriculturally and economically important source of food and beverages. Many of the health beneficial properties of apples are due to (poly)phenolic metabolites that they contain, including various dihydrochalcones. Although many of the genes and enzymes involved in polyphenol biosynthesis are known in many plant species, the specific reactions that lead to the biosynthesis of the dihydrochalcone precursor, p-dihydrocoumaroyl-CoA (3), are unknown. To identify genes involved in the synthesis of these metabolites, existing genome databases of the Rosaceae were screened for apple genes with significant sequence similarity to Arabidopsis alkenal double bond reductases. Herein described are the isolation and characterization of a Malus hydroxycinnamoyl-CoA double bond reductase, which catalyzed the NADPH-dependent reduction of p-coumaroyl-CoA and feruloyl-CoA to p-dihydrocoumaroyl-CoA and dihydroferuloyl-CoA, respectively. Its apparent Km values for p-coumaroyl-CoA, feruloyl-CoA and NADPH were 96.6, 92.9 and 101.3 μM, respectively. The Malus double bond reductase preferred feruloyl-CoA to p-coumaroyl-CoA as a substrate by a factor of 2.1 when comparing catalytic efficiencies in vitro. Expression analysis of the hydroxycinnamoyl-CoA double bond reductase gene revealed that its transcript levels showed significant variation in tissues of different developmental stages, but was expressed when expected for involvement in dihydrochalcone formation. Thus, the hydroxycinnamoyl-CoA double bond reductase appears to be responsible for the reduction of the α,β-unsaturated double bond of p-coumaroyl-CoA, the first step of dihydrochalcone biosynthesis in apple tissues, and may be involved in the production of these compounds.Proposed biosynthetic pathway leading to p-dihydrocoumaroyl-CoA and dihydrochalcones. The NADPH-dependent reduction of p-coumaroyl-CoA to p-dihydro-coumaroyl-CoA is highlighted.

•Characterization of two potential flavone 8-O-methyltransferases from sweet basil.•Analysis of correlation between their gene expression and 8-substituted flavones.•Two possible paths to nevadensin, via 7-O-demethylation or 8-O-methylation as last step.Regioselective 6-,7-,8-,3′-, and 4′-O-methylations underlie the structural diversity of lipophilic flavones produced in the trichomes of sweet basil (Ocimum basilicum L.). The positions 6, 7, and 4′ are methylated by a recently described set of cation-independent enzymes. The roles of cation-dependent O-methyltransferases still require elucidation. Here, the basil trichome EST database was used to identify a Mg2+-dependent O-methyltransferase that was likely to accept flavonoids as substrates. The recombinant protein was found to be active with a wide range of o-diphenols, and methylated the 8-OH moiety of the flavone backbone with higher catalytic efficiency than the 3′-OH group of candidate substrates. To further investigate flavone 8-O-methylation, the activity of a putative cation-independent flavonoid 8-O-methyltransferase from the same EST collection was assessed with available substrate analogs. Notably, it was strongly inhibited by gardenin B, one of its expected products. The catalytic capacities of the two studied proteins suggest that two alternative routes to nevadensin, a major flavone in some basil cultivars, might exist. Correlating the expression of the underlying genes with the accumulation of 8-substituted flavones in four basil lines did not clarify which is the major operating pathway in vivo, yet the combined data suggested that the biochemical properties of flavone 7-O-demethylase could play a key role in determining the reaction order.Characterization of two candidate flavone 8-O-methyltransferases, analysis of underlying genes’ expression and accumulation of relevant flavones in four basil lines suggest two alternative routes to nevadensin in basil trichomes.

A UPLC–MS method was developed for quantifying huperzine A (HupA), an anti-Alzheimer’s disease (AD) drug candidate from the traditional Chinese medicine Qian Ceng Ta (Huperzia serrata), in samples of 11 Huperzia genus plants. The highest content of HupA was found in Huperzia pinifolia. The accumulation of various Lycopodium alkaloids was monitored in these tissues using high resolution Q-IMS-TOFMS analysis. Tissue culture of various Huperzia species has been achieved and production of HupA has been confirmed in the callus of H. pinifolia. Furthermore, it was established that the major alkaloid produced by the naturally grown plant and the callus of H. pinifolia changed dramatically from HupA to nankakurine B.Graphical abstractLC–IMS–MS analysis of Huperzia species grown under controlled conditions sheds light on the regulation of Lycopodium alkaloid biosynthesis. H. pinifolia callus produces nankakurine B instead of huperzine A.Highlights► Huperzia species vary greatly in Lycopodium alkaloid composition and content. ► Controlled growth conditions are important for evaluating alkaloid variation. ► Genetics and the environment play important roles in controlling HupA production. ► H. pinifolia switched from HupA to nankakurine production when callus was induced. ► UPLC–IMS-TOFMS is ideally suited for rapid quantification of Lycopodium alkaloids.

Rhizomes are underground stems that serve various purposes including vegetative propagation, invasion of new territory, and bioactive compound synthesis and storage. An important rhizomatous plant is sacred lotus (Nelumbo nucifera), which is prized in Asia as a medicine and a food. RNA-seq and total transcriptome analysis of rhizomes and other lotus tissues was applied to identify genes involved in rhizome growth, development and metabolism. Root, petiole, rhizome internode, and leaf tissues were used for single-read RNA-seq analysis. Two whole transcriptome paired-end read libraries from rhizome apical tip and elongation zone tissues were also generated in order to survey gene expression profiles. In this analysis, 22,803 genes were expressed: 20,476 in rhizome apical meristem and elongation zone, 17,171 in rhizome internode, 16,656 in leaf, 19,457 in root, and 16,845 in petiole. Gene ontology (GO) analysis indicated that “other membrane”, “nucleotide binding”, and “other cellular processes” were highly represented in the expressed genes. A total of 231 genes displayed rhizome-specific expression including several transcription factors, protein kinases, cytochromes P450 and a sulfate transporter. GOseq analysis showed that genes in the “molecular function” GO category and several genes related to cell proliferation based on KEGG IDs were preferentially up-regulated in rhizome tissue. In addition, 1,251 possible exon-skipping events were observed in 1,149 gene models. These results provide valuable insight into gene expression profiles and regulation in sacred lotus, and the identified rhizome-specific genes provide insight into important processes involved in the biology and development of sacred lotus rhizomes.