Project description:The Lamiaceae family contains numerous diterpenoids, offering a valuable model system for the study of diterpenoid chemical diversity. In this study we report that the ent-kaurene diterpenoids in I. rubescens have the largest diTPS gene family identified in Lamiaceae. Three genes are predicted to be involved in ent-kaurene diterpenoid synthesis while another two KSL genes are functional enzymes utilizing ent-CPP as a substrate. We also showed the presence of a normal-CPP mediated biosynthesis pathway in I. rubescens and that three KSL genes possessing different domain architectures are involved in this pathway. This study provides new information regarding the understanding of diterpenoid chemical diversity and this compounds’ evolution in the Lamiaceae family.
Project description:Next to their essential roles in plant growth and development, phytohormones play a central role in plant immunity against pathogens. In this study we examined the role of hormones in the antagonism of the plant-pathogenic oomycete Pythium arrhenomanes against the root-knot nematode Meloidogyne graminicola in rice roots. Hormone measurements and gene expression analyses showed that the jasmonate (JA) pathway is induced early upon P. arrhenomanes infection. Exogenous application of methyl-jasmonate (MeJA) on the plant confirmed that JA is needed for basal defence against both P. arrhenomanes and M. graminicola in rice. Whereas M. graminicola suppresses root JA levels to increase host susceptibility, Pythium inoculation boosts JA accumulation up to levels that can no longer be repressed by the nematode in double-inoculated plants. Exogenous MeJA supply phenocopied the defence-inducing capacity of P. arrhenomanes against the root-knot nematode, whereas the antagonism was weakened in JA-insensitive mutants. Transcriptome analysis confirmed upregulation of JA biosynthesis and signalling genes upon P. arrhenomanes infection, and additionally revealed induction of genes involved in biosynthesis of diterpenoid phytoalexins, consistent with strong activation of the gene encoding the JA-inducible transcriptional regulator DITERPENOID PHYTOALEXIN FACTOR. Next to that, our results provide evidence for induced expression of genes encoding ERF83, and related PR proteins, as well as auxin depletion in P. arrhenomanes infected rice roots, which potentially further contributes to the reduced nematode susceptibility seen in double-infected plants.
Project description:Chinese cedar (<i>Cryptomeria fortunei</i>) is a tree species with important ornamental, medicinal, and economic value. Terpenoids extracted from the essential oil of <i>C. fortunei</i> needles have been considered valuable ingredients in the pharmaceutical and cosmetic industries. However, the possible gene regulation mechanisms that limit terpenoid biosynthesis in this genus are poorly understood. Here, we adopted integrated metabolome analysis, transcriptome, small-RNA (sRNA), and degradome sequencing to analyze the differences in terpenoid regulatory mechanisms in two different overwintering <i>C. fortunei</i> phenotypes (wild-type and an evergreen mutant). A total of 1447/6219 differentially synthesized metabolites (DSMs)/unigenes (DEGs) were detected through metabolome/transcriptome analyses, and these DSMs/DEGs were significantly enriched in flavonoid and diterpenoid biosynthesis pathways. In <i>C. fortunei</i> needles, 587 microRNAs (miRNAs), including 67 differentially expressed miRNAs (DERs), were detected. Among them, 8346 targets of 571 miRNAs were predicted using degradome data, and a 72-miRNA-target regulatory network involved in the metabolism of terpenoids and polyketides was constructed. Forty-one targets were further confirmed to be involved in terpenoid backbone and diterpenoid biosynthesis, and target analyses revealed that two miRNAs (i.e., aly-miR168a-5p and aof-miR396a) may be related to the different phenotypes and to differential regulation of diterpenoid biosynthesis. Overall, these results reveal that <i>C. fortunei</i> plants with the evergreen mutation maintain high terpenoid levels in winter through miRNA-target regulation, which provides a valuable resource for essential oil-related bioengineering research.
Project description:Tanshinones are the bioactive nor-diterpenoid constituents of the Chinese medicinal herb Danshen (Salvia miltiorrhiza). A lot of studies have testified that biosynthesis of tanshinones were regulated by transcription factors. However, the upstream regulating mechanism of tanshinones biosynthesis was still not completely uncovered. In this study, the kinase which involved in tanshinones biosynthesis was identified through proteomic approach. The downstream targeted transcription factors were screened out through phosphorproteomics
Project description:The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) of S. mutans upon the treatment of three types of diterpenoid
