Chromosomal-level genome of velvet bean (Mucuna pruriens) provides resources for L-DOPA synthetic research and development.

Mucuna pruriens, commonly called velvet bean, is the main natural source of levodopa (L-DOPA), which has been marketed as a psychoactive drug for the clinical management of Parkinson's disease and dopamine-responsive dystonia. Although velvet bean is a very important plant species for food and pharmaceutical manufacturing, the lack of genetic and genomic information about this species severely hinders further molecular research thereon and biotechnological development. Here, we reported the first velvet bean genome, with a size of 500.49 Mb and 11 chromosomes encoding 28,010 proteins. Genomic comparison among legume species indicated that velvet bean speciated ∼29 Ma from soybean clade, without specific genome duplication. Importantly, we identified 21 polyphenol oxidase coding genes that catalyse l-tyrosine to L-DOPA in velvet bean, and two subfamilies showing tandem expansion on Chr3 and Chr7 after speciation. Interestingly, disease-resistant and anti-pathogen gene families were found contracted in velvet bean, which might be related to the expansion of polyphenol oxidase. Our study generated a high-quality genomic reference for velvet bean, an economically important agricultural and medicinal plant, and the newly reported L-DOPA biosynthetic genes could provide indispensable information for the biotechnological and sustainable development of an environment-friendly L-DOPA biosynthesis processing method.

The complete chloroplast genome of a shrub species, Smilax glabra (Smilacaceae) from Guangdong, China.

Smilax glabra is a perennial woody scandent shrub, of which the dried aerial tuber has been used as Chinese medicine. Here, we sequenced S. glabra and assembled its complete chloroplast (cp) genome. The genome is 157,889 bp in length and has a typical quadripartite structure. We annotated 131 genes, of which 84 were protein-coding genes, 37 were tRNAs and 8 were rRNA genes. Phylogenetic analysis of this genome with 26 representatives Liliales fully resolved S. glabra in a clade with S. china. The phylogenetic tree we constructed is largely consistent with recently published phylogenetic trees using both complete chloroplast genomes and marker gene sequences.

Chromosome-level genome of Himalayan yew provides insights into the origin and evolution of the paclitaxel biosynthetic pathway.

Taxus, commonly known as yew, is a well-known gymnosperm with great ornamental and medicinal value. In this study, by assembling a chromosome-level genome of the Himalayan yew (Taxus wallichiana) with 10.9 Gb in 12 chromosomes, we revealed that tandem duplication acts as the driving force of gene family evolution in the yew genome, resulting in the main genes for paclitaxel biosynthesis, i.e. those encoding the taxadiene synthase, P450s, and transferases, being clustered on the same chromosome. The tandem duplication may also provide genetic resources for the nature to sculpt the core structure of taxoids at different positions and subsequently establish the complex pathway of paclitaxel by neofunctionalization. Furthermore, we confirmed that there are two genes in the cluster encoding isoenzymes of a known enzyme in the paclitaxel biosynthetic pathway. The reference genome of the Himalayan yew will serve as a platform for decoding the complete biosynthetic pathway of paclitaxel and understanding the chemodiversity of taxoids in gymnosperms.

Draft Genomes and Comparative Analysis of Seven Mangrove Rhizosphere-Associated Fungi Isolated From Kandelia obovata and Acanthus ilicifolius.

Mangroves are one of the most productive and biologically diverse ecosystems, with unique plants, animals, and microorganisms adapted to the harsh coastal environments. Although fungi are widely distributed in the mangrove ecosystem and they are playing an important role in the decomposition of organic matter, their genomic profiles are still poorly understood. In this study, we isolated seven Ascomycota fungi (Westerdykella dispersa F012, Trichoderma lixii F014, Aspergillus tubingensis F023, Penicillium brefeldianum F032, Neoroussoella solani F033, Talaromyces fuscoviridis F034, and Arthrinium marii F035) from rhizospheres of two mangroves of Kandelia obovata and Acanthus ilicifolius. We sequenced and assembled the whole genome of these fungi, resulting in size ranging from 29 to 48 Mb, while contig N50 from 112 to 833 Kb. We generated six novel fungi genomes except A. tubingensis, and the gene completeness and genome completeness of all seven genomes are higher than 94%. Comparing with non-mangrove fungi, we found Carbohydrate-Binding Modules (CBM32), a subfamily of carbohydrate active enzymes, only detected in two mangrove fungi. Another two subfamilies, Glycoside Hydrolases (GH6) and Polysaccharide Lyases (PL4), were significantly different in gene copy number between K. obovata and A. ilicifolius rhizospheres (P-value 0.041 for GH6, 0.047 for PL4). These findings may indicate an important influence of mangrove environments or hosts on the ability of decomposition in rhizosphere fungi. Secondary metabolite biosynthesis gene clusters were detected and we found the mangrove fungi averagely contain 18 Type I Polyketide (t1pks) synthase, which was significantly higher than 13 in non-mangrove fungi (P-value 0.048), suggesting their potential roles in producing bioactive compounds that important for fungi development and ecology. We reported seven mangrove-associated fungal genomes in this study and compared their carbohydrate active enzymes and secondary metabolites (SM) genes with those of non-mangrove fungi, and the results suggest that there are differences in genetic information among fungi in different habitats.