Biosynthesis Of Bioactive Compounds Research Articles

Genome-wide characterization and comparative analysis of R2R3-MYB transcription factors shows the complexity of MYB-associated regulatory networks in Salvia miltiorrhiza.

BackgroundMYB is the largest plant transcription factor gene family playing vital roles in plant growth and development. However, it has not been systematically studied in Salvia miltiorrhiza, an economically important medicinal plant.ResultsHere we report the genome-wide identification and characterization of 110 R2R3-MYBs, the largest subfamily of MYBs in S. miltiorrhiza. The MYB domain and other motifs of SmMYBs are largely conserved with Arabidopsis AtMYBs, whereas the divergence of SmMYBs and AtMYBs also exists, suggesting the conservation and diversity of plant MYBs. SmMYBs and AtMYBs may be classified into 37 subgroups, of which 31 include proteins from S. miltiorrhiza and Arabidopsis, whereas 6 are specific to a species, indicating that the majority of MYBs play conserved roles, while others may exhibit species-specialized functions. SmMYBs are differentially expressed in various tissues of S. miltiorrhiza. The expression profiles are largely consistent with known functions of their Arabidopsis counterparts. The expression of a subset of SmMYBs is regulated by microRNAs, such as miR159, miR319, miR828 and miR858. Based on functional conservation of MYBs in a subgroup, SmMYBs potentially involved in the biosynthesis of bioactive compounds were identified.ConclusionsA total of 110 R2R3-MYBs were identified and analyzed. The results suggest the complexity of MYB-mediated regulatory networks in S. miltiorrhiza and provide a foundation for understanding the regulatory mechanism of SmMYBs.

The phenylalanine ammonia-lyase gene family in Salvia miltiorrhiza: genome-wide characterization, molecular cloning and expression analysis

Salvia miltiorrhiza Bunge is a well-known material of traditional Chinese medicine. Hydrophilic phenolic acids, such as rosmarinic acid and salvianolic acid B, are a group of pharmaceutically important compounds in S. miltiorrhiza. The biosynthesis of rosmarinic acid requires the coordination of the phenylpropanoid pathway and the tyrosine-derived pathway. Phenylalanine ammonia-lyase (PAL) is the first key enzyme of the phenylpropanoid pathway. Systematic analysis of the SmPAL gene family has not been carried out. We report here the identification of three SmPALs through searching the recently obtained working draft of the S. miltiorrhiza genome and full-length cDNA cloning. Bioinformatic and phylogenetic analyses showed that SmPAL1 and SmPAL3 clustered in a sub-clade of dicot PALs, whereas SmPAL2 fell into the other one. Some important cis-elements were conserved in three SmPAL promoters, whereas the others were not. SmPAL1 and SmPAL3 were highly expressed in roots and leaves of S. miltiorrhiza, but SmPAL2 were predominately expressed in stems and flowers. It indicates that SmPAL1 and SmPAL3 function redundantly in rosmarinic acid biosynthesis. All SmPALs were induced in roots treated with PEG and MeJA, but the time and degree of responses were different, suggesting the complexity of SmPAL-associated metabolic network in S. miltiorrhiza. This is the first comprehensive study dedicated to SmPAL gene family characterization. The results provide a basis for elucidating the role of SmPAL genes in the biosynthesis of bioactive compounds.

Effects of PAR and UV‐B Radiation on Herbal Yield, Bioactive Compounds and Their Antioxidant Capacity of Some Medicinal Plants Under Controlled Environmental Conditions

Photosynthetically active radiation (PAR) and Ultraviolet B (UV-B) radiation are among the main environmental factors acting on herbal yield and biosynthesis of bioactive compounds in medicinal plants. The objective of this study was to evaluate the influence of biologically effective UV-B light (280-315nm) and PAR (400-700nm) on herbal yield, content and composition, as well as antioxidant capacity of essential oils and polyphenols of lemon catmint (Nepeta cataria L. f. citriodora), lemon balm (Melissa officinalis L.) and sage (Salvia officinalis L.) under controlled greenhouse cultivation. Intensive UV-B radiation (2.5kJm(-2) d(-1) ) influenced positively the herbal yield. The essential oil content and composition of studied herbs were mainly affected by PAR and UV-B radiation. In general, additional low-dose UV-B radiation (1kJm(-2) d(-1) ) was most effective for biosynthesis of polyphenols in herbs. Analysis of major polyphenolic compounds provided differences in sensitivity of main polyphenols to PAR and UV-B radiation. Essential oils and polyphenol-rich extracts of radiated herbs showed essential differences in antioxidant capacity by the ABTS system. Information from this study can be useful for herbal biomass and secondary metabolite production with superior quality under controlled environment conditions.

Investigation of the biosynthetic potential of endophytes in traditional Chinese anticancer herbs.

Traditional Chinese medicine encompasses a rich empirical knowledge of the use of plants for the treatment of disease. In addition, the microorganisms associated with medicinal plants are also of interest as the producers of the compounds responsible for the observed plant bioactivity. The present study has pioneered the use of genetic screening to assess the potential of endophytes to synthesize bioactive compounds, as indicated by the presence of non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes. The total DNA extracts of 30 traditional Chinese herbs, were screened for functional genes involved in the biosynthesis of bioactive compounds. The four PCR screens were successful in targeting four bacterial PKS, six bacterial NRPS, ten fungal PKS and three fungal NRPS gene fragments. Analysis of the detected endophyte gene fragments afforded consideration of the possible bioactivity of the natural products produced by endophytes in medicinal herbs. This investigation describes a rapid method for the initial screening of medicinal herbs and has highlighted a subset of those plants that host endophytes with biosynthetic potential. These selected plants can be the focus of more comprehensive endophyte isolation and natural product studies.

Phytosymbiosis of aerobic methylobacteria: New facts and views

This review highlightsrecent findings on the phytosymbiosis of aerobic methylobacteria, including their biodiversity, occurrence, and their role in associations with plants, as well as the capacity for biosynthesis of bioactive compounds (auxins, cytokinins, and vitamin Bl2) and nitrogen fixation. Future research directions in phytosymbiosis of aerobic methylobacteria during the postgenomics era are discussed.

ChemInform Abstract: Hutchinson′s Legacy: Keeping on Polyketide Biosynthesis

AbstractReview: 93 refs.

Hutchinson's legacy: keeping on polyketide biosynthesis

Professor Charles Richard Hutchinson (Hutch) dedicated his research to the study of polyketide compounds, in particular, those produced by actinomycetes. Hutch principally centered his efforts to study the biosynthesis of bioactive compounds, antibiotic and antitumor drugs, and to develop new derivatives with improved therapeutic properties. After dedicating 40 years to the study of polyketides, Hutch leaves us, as legacy, the knowledge that he and his collaborators have accumulated and shared with the scientific community. The best tribute we can offer to him is keeping on the study of polyketides and other bioactive compounds, in an effort to generate more safer and useful drugs. In this review, the work on the polyketides, borrelidin, steffimycin and streptolydigin, performed at the laboratory of Professors Salas and Méndez at University of Oviedo (Spain) during the last 10 years, is summarized.

Comparison of 454-ESTs from Huperzia serrata and Phlegmariurus carinatus reveals putative genes involved in lycopodium alkaloid biosynthesis and developmental regulation

BackgroundPlants of the Huperziaceae family, which comprise the two genera Huperzia and Phlegmariurus, produce various types of lycopodium alkaloids that are used to treat a number of human ailments, such as contusions, swellings and strains. Huperzine A, which belongs to the lycodine type of lycopodium alkaloids, has been used as an anti-Alzheimer's disease drug candidate. Despite their medical importance, little genomic or transcriptomic data are available for the members of this family. We used massive parallel pyrosequencing on the Roche 454-GS FLX Titanium platform to generate a substantial EST dataset for Huperzia serrata (H. serrata) and Phlegmariurus carinatus (P. carinatus) as representative members of the Huperzia and Phlegmariurus genera, respectively. H. serrata and P. carinatus are important plants for research on the biosynthesis of lycopodium alkaloids. We focused on gene discovery in the areas of bioactive compound biosynthesis and transcriptional regulation as well as genetic marker detection in these species.ResultsFor H. serrata, 36,763 unique putative transcripts were generated from 140,930 reads totaling over 57,028,559 base pairs; for P. carinatus, 31,812 unique putative transcripts were generated from 79,920 reads totaling over 30,498,684 base pairs. Using BLASTX searches of public databases, 16,274 (44.3%) unique putative transcripts from H. serrata and 14,070 (44.2%) from P. carinatus were assigned to at least one protein. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology annotations revealed that the functions of the unique putative transcripts from these two species cover a similarly broad set of molecular functions, biological processes and biochemical pathways.In particular, a total of 20 H. serrata candidate cytochrome P450 genes, which are more abundant in leaves than in roots and might be involved in lycopodium alkaloid biosynthesis, were found based on the comparison of H. serrata and P. carinatus 454-ESTs and real-time PCR analysis. Four unique putative CYP450 transcripts (Hs01891, Hs04010, Hs13557 and Hs00093) which are the most likely to be involved in the biosynthesis of lycopodium alkaloids were selected based on a phylogenetic analysis. Approximately 115 H. serrata and 98 P. carinatus unique putative transcripts associated with the biosynthesis of triterpenoids, alkaloids and flavones/flavonoids were located in the 454-EST datasets. Transcripts related to phytohormone biosynthesis and signal transduction as well as transcription factors were also obtained. In addition, we discovered 2,729 and 1,573 potential SSR-motif microsatellite loci in the H. serrata and P. carinatus 454-ESTs, respectively.ConclusionsThe 454-EST resource allowed for the first large-scale acquisition of ESTs from H. serrata and P. carinatus, which are representative members of the Huperziaceae family. We discovered many genes likely to be involved in the biosynthesis of bioactive compounds and transcriptional regulation as well as a large number of potential microsatellite markers. These results constitute an essential resource for understanding the molecular basis of developmental regulation and secondary metabolite biosynthesis (especially that of lycopodium alkaloids) in the Huperziaceae, and they provide an overview of the genetic diversity of this family.