Metabolome and transcriptome profiling reveal regulatory network and mechanism of flavonoid biosynthesis during color formation of Dioscorea cirrhosa L.

Dioscorea cirrhosa is a plant that is used as a dye as well as in medicine. Many metabolites with pharmacological activity exist in the tubers of D. cirrhosa. However, little is known about the mechanism regulating biosynthesis in these metabolites. In this study, transcriptome and metabolome profiling were performed in four color tubers. A total of 531 metabolites, including 62 flavonoids, were identified. Epicatechin and proanthocyanin B2 were the key metabolites that exhibited high content levels in the four tubers. These metabolites were divided into nine classes with distinct change patterns. A total of 22,865 differentially expressed genes (DEGs) were identified by transcriptome analysis. Among these DEGs, we identified 67 candidate genes related to the flavonoid biosynthesis pathway and three genes that played pivotal roles in proanthocyanin (PA) synthesis. A weighted gene co-expression network analysis (WGCNA) revealed that the two modules, "MEblue" and "MEblack," were two key gene sets strongly associated with phenylpropanoid and flavonoid biosynthesis. We also found that the plant hormone signal transduction biological process exhibited activity in the late stage of tuber color formation. Additionally, we identified 37 hub transcript factors related to flavonoid biosynthesis, of which 24 were found to be highly associated with flavonoid pathway genes. In addition to the MYB-bHLH-WD40 (MBW) genes, we found that the plant hormone gene families exhibited high expression levels. This study provides a reference for understanding the synthesis of D. cirrhosa tuber metabolites at the molecular level and provides a foundation for the further development of D. cirrhosa related plant pigments as well as its further use in the pharmaceutical industry.

Nomenclature and taxonomic identities of Prunuszappeyana and P.zappeyanavar.subsimplex (Rosaceae).

The original specimens of both Prunuszappeyana and P.zappeyanavar.subsimplex were found to belong to more than one taxon. In addition, P.zappeyanavar.subsimplex was found to be invalid because, when the name was published, two separate descriptions were given to two cited collections, but not to the taxon, making the name unaccompanied with a description or diagnosis of this taxon (Art. 38.1 (a)). Therefore, a lectotype of P.zappeyana was designated under Art. 9.11 of ICN, by which P.zappeyana was placed in the synonymy of P.veitchii.

Tigridiopalma exalata, a new and endangered species of Melastomataceae from China.

A new species of the genus Tigridiopalma, formerly considered monotypic, is here described as T. exalata and illustrated based on molecular and morphological evidence. It is morphologically similar to T. magnifica in having a short stem, huge basal leaves, scorpioid cymes, and 5-merous flowers, but differs in having ribbed and pale yellow puberulent petioles, purple petals with a small white apical patch, connectives of longer stamens with a distinct dorsal short spur at their base, and wingless capsules. Due to the restricted distribution, small populations and horticultural potential of this new species, it should be categorized as an Endangered species (EN).

The use of medicinal plants to prevent COVID-19 in Nepal.

BACKGROUND: Medicinal plants are the fundamental unit of traditional medicine system in Nepal. Nepalese people are rich in traditional medicine especially in folk medicine (ethnomedicine), and this system is gaining much attention after 1995. The use of medicinal plants has increased during the COVID-19 pandemic as a private behavior (not under the control of government). A lot of misinterpretations of the use of medicinal plants to treat or prevent COVID-19 have been spreading throughout Nepal which need to be managed proactively. In this context, a research was needed to document medicinal plants used, their priority of use in society, their cultivation status, and the source of information people follow to use them. This study aimed to document the present status of medicinal plant use and make important suggestion to the concerned authorities. METHODS: This study used a web-based survey to collect primary data related to medicinal plants used during COVID-19. A total of 774 respondents took part in the survey. The study calculated the relative frequencies of citation (RFC) for the recorded medicinal plants. The relationship between plants recorded and different covariates (age, gender education, occupation, living place, and treatment methods) was assessed using Kruskal-Wallis test and Wilcoxon test. The relationship between the information sources people follow and the respondent characteristics was assessed using chi-square test. RESULTS: The study found that the use of medicinal plants has increased during COVID-19 and most of the respondents recommended medicinal plants to prevent COVID-19. This study recorded a total of 60 plants belonging to 36 families. The leaves of the plants were the most frequently used. The Zingiber officinale was the most cited species with the frequency of citation 0.398. Most of the people (45.61%) were getting medicinal plants from their home garden. The medicinal plants recorded were significantly associated with the education level, location of home, primary treatment mode, gender, and age class. The information source of plants was significantly associated with the education, gender, method of treatment, occupation, living with family, and location of home during the lockdown caused by COVID-19. CONCLUSIONS: People were using more medicinal plants during COVID-19 claiming that they can prevent or cure COVID-19. This should be taken seriously by concerned authorities. The authorities should test the validity of these medicinal plants and control the flow of false information spread through research and awareness programs.

The identity of Prunusdielsiana (Rosaceae).

The valid publication date of Prunusdielsiana was found to be later than that of P.rufoides, which has been considered a synonym of P.dielsiana. Prunusdielsiana is therefore reduced to a synonym of P.rufoides, instead of the reverse. In addition, all previously named varieties of Prunusdielsiana, including var. abbreviata, var. conferta, and var. laxa, as well as P.carcharias are also listed as synonyms of P.rufoides in the present paper.

Taxonomic reconsideration of Prunusveitchii (Rosaceae).

Prunusveitchii was published in 1912 and was treated as a synonym of P.serrulatavar.pubescens. The information about this taxon is relatively scarce. When consulting specimens of Prunus L., type materials of Prunusveitchii were found to belong to three taxa and P.veitchii, P.concinna, P.japonicavar.zhejiangensis, C.jingningensis and C.xueluoensis were found to be conspecific. The taxonomic status of P.veitchii is reconsidered in the present paper. Morphometric analyses were performed to evaluate the significance of differences between P.veitchii and P.serrulatavar.pubescens. The results show that the leaves of P.veitchii are significantly smaller and narrower than the leaves of P.serrulatavar.pubescens and the peduncle and pedicels are shorter. According to the results of morphometric analyses, P.veitchii should be treated as a separate species. To address these results, a lectotype of P.veitchii is designated here and P.concinna, Cerasusjingningensis and C.xueluoensis are here designated as synonyms of P.veitchii.

Genetic variability and population structure of Disanthus cercidifolius subsp. longipes (Hamamelidaceae) based on AFLP analysis.

Disanthus cercidifolius subsp. longipes is an endangered species in China. Genetic diversity and structure analysis of this species was investigated using amplified fragments length polymorphism (AFLP) fingerprinting. Nei's gene diversity ranged from 0.1290 to 0.1394. The AMOVA indicated that 75.06% of variation was distributed within populations, while the between-group component 5.04% was smaller than the between populations-within-group component 19.90%. Significant genetic differentiation was detected between populations. Genetic and geographical distances were not correlated. PCA and genetic structure analysis showed that populations from East China were together with those of the Nanling Range. These patterns of genetic diversity and levels of genetic variation may be the result of D. c. subsp. longipes restricted to several isolated habitats and "excess flowers production, but little fruit set". It is necessary to protect all existing populations of D. c. subsp. longipes in order to preserve as much genetic variation as possible.