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Dioscorea zingiberensis (Dioscoreceae) is the main plant source of diosgenin (steroidal sapogenins), the precursor for the production of steroid hormones in the pharmaceutical industry. Despite its large economic value, genomic information of the genus Dioscorea is currently unavailable. Here, we present an initial survey of the D. zingiberensis genome performed by next-generation sequencing technology together with a genome size investigation inferred by flow cytometry. The whole genome survey of D. zingiberensis generated 31.48 Gb of sequence data with approximately 78.70x coverage. The estimated genome size is 800 Mb, with a high level of heterozygosity based on K-mer analysis. These reads were assembled into 334 288 contigs with a N50 length of 1079 bp, which were further assembled into 92 163 scaffolds with a total length of 173.46 Mb. A total of 4935 genes, 81 tRNAs, 69 rRNAs, and 661 miRNAs were predicted by the genome analysis, and 263 484 repeated sequences were obtained with 419 372 simple sequence repeats (SSRs). Among these SSRs, the mononucleotide repeat type was the most abundant (up to 54.60% of the total SSRs), followed by the dinucleotide (29.60%), trinucleotide (11.37%), tetranucleotide (3.53%), pentanucleotide (0.65%), and hexanucleotide (0.25%) repeat types. The 1C-value of D. zingiberensis was calibrated against Salvia miltiorrhiza and calculated as 0.87 pg (851 Mb) by flow cytometry, which was very close to the result of the genome survey. This is the first report of genome-wide characterization within this taxon. Key words: Dioscorea zingiberensis, genome survey sequencing, genome analysis. Le Dioscorea zingiberensis (Dioscoreceae) est la principale source végétale de la diosgénine (saponigénines stéroïdiennes), le précurseur de la production d'hormones stéroïdiennes dans l'industrie pharmaceutique. En dépit de sa grande valeur économique, l'information génomique au sein du genre Dioscorea est présentement indisponible. Dans ce travail, les auteurs présentent le fruit d'un survol initial du génome du D. zingiberensis au moyen d'une approche de séquençage de nouvelle génération et d'une investigation de la taille du génome par cytométrie en flux. Le séquençage du génome du D. zingiberensis a généré 31,48 Gb de données, soit une couverture d'environ 78,70x. La taille estimée du génome est de 800 Mb, avec un degré élevé d'hétérozygotie sur la base de l'analyse des k-mers. Les courtes séquences ont été assemblées en 334 288 contigs avec un N50 de 1079 pb, lesquels ont été ensuite assemblés en 92 163 supercontigs dont la taille totalisait 173,46 Mb. Au total, 4935 gènes, 81 ARNt, 69 ARNr et 661 miARN ont été prédits suite à l'analyse du génome et 263 484 séquences répétées ont été obtenues incluant 419 372 microsatellites (SSR). Parmi ces SSR, les répétitions mononucléotidiques étaient les plus abondantes (jusqu'à 54,60% de tous les SSR), suivies des répétitions dinucléotidiques (29,60%), trinucléotidiques (11,37%), tétranucléotidiques (3,53%), pentanucléotidiques (0,65%) et hexanucléotidiques (0,25%). [Traduit par la Rédaction] Mots-clés: Dioscorea zingiberensis, séquençage génomique superficiel, analyse du génome., Introduction Dioscorea zingiberensis is an important and widely used medicinal herb in Traditional Chinese Medicine (TCM). It has been applied for the treatment of various diseases, such as cough, anthrax, [...]

WRKY, named for its special heptapeptide conserved sequence WRKYGOK, is one of the largest transcription factor families in plants and is widely involved in plant responses to biotic, abiotic, and hormonal stresses, especially the important regulatory function in response to drought stress. However, there is no complete comprehensive analysis of this family in H. perforatum, which is one of the most extensively studied plants and is probably the best-known herbal medicine on the market today, serving as an antidepressant, neuroprotective, an antineuralgic, and an antiviral. Here, we identified 86 HpWRKY genes according to the whole genome database of H. perforatum, and classified them into three groups through phylogenetic analysis. Gene structure, conserved domain, motif, cis-elements, gene ontology, and expression profiling were performed. Furthermore, it was found that HpWRKY85, a homologous gene of AtWRKY75, showed obvious responses to drought treatment. Subcellular localization analysis indicated that this protein was localized in the nucleus by the Arabidopsis protoplasts transient transfection. Meanwhile, HpWRKY85-overexpressing Arabidopsis plants showed a stronger ability of root growth and scavenging endogenous reactive oxygen species. The results provide a reference for further understanding the role of HpWRKY85 in the molecular mechanism of drought resistance of H. perforatum. [ABSTRACT FROM AUTHOR]

Scutellaria baicalensis Georgi is an annual herb from the Scutellaria genus that has been extensively used as a traditional medicine for over 2000 years in China. Baicalin and other flavonoids have been identified as the principal bioactive ingredients. The biosynthetic pathway of baicalin in S. baicalensis has been elucidated; however, the specific functions of R2R3-MYB TF, which regulates baicalin synthesis, has not been well characterized in S. baicalensis to date. Here, a S20 R2R3-MYB TF (SbMYB12), which encodes 263 amino acids with a length of 792 bp, was expressed in all tested tissues (mainly in leaves) and responded to exogenous hormone methyl jasmonate (MeJA) treatment. The overexpression of SbMYB12 significantly promoted the accumulation of flavonoids such as baicalin and wogonoside in S. baicalensis hairy roots. Furthermore, biochemical experiments revealed that SbMYB12 is a nuclear-localized transcription activator that binds to the SbCCL7-4, SbCHI-2, and SbF6H-1 promoters to activate their expression. These results illustrate that SbMYB12 positively regulates the generation of baicalin and wogonoside. In summary, this work revealed a novel S20 R2R3-MYB regulator and enhances our understanding of the transcriptional and regulatory mechanisms of baicalin biosynthesis, as well as sheds new light on metabolic engineering in S. baicalensis. [ABSTRACT FROM AUTHOR]