The research progresses and future prospects of Tetrastigma hemsleyanum Diels et Gilg: A valuable Chinese herbal medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Tetrastigma hemsleyanum Diels et Gilg, known as Sanyeqing in China, was an extensively used folk Chinese herbal medicine. This plant had been validated to be highly effective for treating high fever, pneumonia, hepatitis, gastritis, cervicitis, lymphatic tuberculosis, septicemia, and viral meningitis. AIM OF THE REVIEW: As a review in T. hemsleyanum, this article aims to provide a critical and comprehensive evaluation for future research as well as the development of new drugs. The possible uses and future research directions of this plant were also discussed. MATERIALS AND METHODS: A literature search was conducted on different scientific search engines, including Google Scholar, Science Direct, PubMed, Web of Science, and CNKI. Additional information was obtained from classic books about Chinese herbal medicine and scientific databases. RESULTS: T. hemsleyanum was a perennial herb climbing vine, which was mainly based on field cultivation. About 150 chemical compounds have been isolated from T. hemsleyanum, including flavonoids, phenolic acids, polysaccharides, triterpenoids, steroids, and organic acids. Studies on the physiological aspects of T. hemsleyanum have been focused on the effects of light and fertilizer on their growth, and few other studies have been conducted. The plant had widespread pharmacological effects on the immune system, as well as anti-tumor, anti-inflammatory, analgesic, and antipyretic. CONCLUSIONS: T. hemsleyanum was a valuable traditional Chinese medical herb with pharmacological activities that mainly affected the immune system. This review summarized its botanical description, cultivation techniques, physiology, ethnopharmacology, chemical components, and pharmacological functions. This information suggested that we should focus on the development of new drugs related to T. hemsleyanum. Meanwhile, it was important to emphasize the traditional use of T. hemsleyanum, avoiding over-harvesting that exerted a great impact on resource scarcity. And developing its new clinical usage and comprehensive utilize would augment the therapeutic potentials of T. hemsleyanum.

Evolutionary insights from comparative transcriptome and transcriptome-wide coalescence analyses in Tetrastigma hemsleyanum.

BACKGROUND: Tetrastigma hemsleyanum is of great medicinal importance and used as a model system to address the evolutionary history of warm-temperate evergreen (WTE) forest biomes in East Asia over Neogene time scales. However, further studies on the neutral and adaptive divergence processes of T. hemsleyanum are currently impeded by a lack of genomic resources. In this study, we de novo assembled and annotated a reference transcriptome for two cpDNA lineages (Central-South-East vs. Southwest) of T. hemsleyanum. We further used comparative genomic and multilocus coalescent approaches to investigate the tempo and mode of lineage diversification in T. hemsleyanum. RESULTS: A total of 52,838 and 65,197 unigenes with an N50 of 1,667 and 1,841 bp for Central-South-East (CSE) and Southwest (SW) lineages, respectively, were recovered, and 6,692 putative orthologs were identified between the two lineages. Estimation of Ka/Ks ratios for these orthologs revealed that ten genes had Ka/Ks values significantly greater than 0.5 (P < 0.05), whereas 2,099 (Ka/Ks < 0.5, P < 0.05) were inferred to be under purifying selection. Based on three bioinformatic strategies, we identified a total of 1,018 single-copy nuclear genes (SCNGs) from the orthologs. We successfully designed eight nuclear gene primer pairs with high intraspecific variation (e.g. hT = 0.923, πT = 1.68×10-3), when surveyed across a subset of T. hemsleyanum individuals. Concordant with the previous cpDNA data, the haplotype networks constructed for most nuclear gene loci clearly identified the two lineages. A multilocus coalescence analysis suggested that the separation between the two lineages appears to have occurred during the mid-Pliocene. Despite their ancient divergence, both lineages experienced expansion at rather localized scales and have continued to exchange genes at a low rate. CONCLUSIONS: This study demonstrated the utility of transcriptome sequencing as a basis for SCNG development in non-model species and the advantages of integrating multiple nuclear loci for phylogeographic and phylogenetic studies.

Self-discrimination in the tendrils of the vine Cayratia japonica is mediated by physiological connection.

Although self-discrimination has been well documented, especially in animals, self-discrimination in plants has been identified in only a few cases, such as self-incompatibility in flowers and root discrimination. Here, were port a new form of self-discrimination in plants: discrimination by vine tendrils. We found that tendrils of the perennial vine Cayratia japonica were more likely to coil around neighbouring non-self plants than neighbouring self plants in both experimental and natural settings. The higher level of coiling around a physiologically severed self plant compared with that around a physiologically connected self plant suggested that self-discrimination was mediated by physiological coordination between the tendril and the touched plant as reported for self-discrimination in roots. The results highlight the importance of self-discrimination for plant competition not only underground,but also above-ground.

Quantifying the attachment strength of climbing plants: a new approach.

In order to grow vertically, it is essential for climbing plants to firmly attach to their supporting structures. In climbing plants, different strategies for permanent attachment can be distinguished. Besides twining stems and tendrils, many plants use attachment pads or attachment roots for this purpose. Using a novel custom-built tensile testing setup, the mechanical properties of different permanent attachment structures of self-clinging plant species were investigated, namely the attachment pads of Boston ivy (Parthenocissus tricuspidata), the attachment roots of ivy (Hedera helix) and the clustered attachment roots of trumpet creeper (Campsis radicans). Force-displacement measurements of individual attachment pads as well as of complete structures consisting of several pads or roots were conducted for both natural and laboratory growth conditions. The shapes of the curves and the maximum forces determined indicate clear differences in the detachment process for the different plants and structures tested. Based on these findings, it is argued that the attachment structures are displacement-optimized rather than force-optimized.