Comparative genomics analysis reveals gene family expansion and changes of expression patterns associated with natural adaptations of flowering time and secondary metabolism in yellow <Emphasis Type="Italic">Camellia</Emphasis>

Yellow-flowering species are unique in the genus Camellia not only for their bright yellow pigments but also the health-improving substances in petals. However, little is known regarding the biosynthesis pathways of pigments and secondary metabolites. Here, we performed comparative genomics studies in two yellow-flowered species of the genus Camellia with distinctive flowering periods. We obtained 112,190 and 89,609 unigenes from Camellia nitidissima and Camellia chuongtsoensis, respectively, and identified 9547 gene family clusters shared with various plant species and 3414 single-copy gene families. Global gene expression analysis revealed six comparisons of differentially expressed gene sets in different developmental stages of floral bud. Through the identification of orthologous pairs, conserved and specific differentially expressed genes (DEGs) between species were compared. Functional enrichment analysis suggested that the gibberellin (GA) biosynthesis pathway might be related to the alteration of flowering responses. Furthermore, the expression patterns of secondary metabolism pathway genes were analyzed between yellow- and red-flowered Camellias. We showed that the key enzymes involved in glycosylation of flavonoids displayed differential expression patterns, indicating that the direct glycosylation of flavonols rather than anthocyanins was pivotal to coloration and health-improving metabolites in the yellow Camellia petals. Finally, the gene family analysis of UDP-glycosyltransferases revealed an expansion of group C members in C. nitidissima. Through comparative genomics analysis, we demonstrate that changes of gene expression and gene family members are critical to the variation of natural traits. This work provides valuable insights into the molecular regulation of trait adaptations of floral pigmentation and flowering timing.     

Impact of traditional culture on <Emphasis Type="Italic">Camellia reticulata</Emphasis> in Yunnan,China

Background

Cha-hua (Camellia reticulata) is one of China’s traditional ornamental flowers developed by the local people of Yunnan Province. Today, more than 500 cultivars and hybrids are recognized. Many ancient camellia trees still survive and are managed by local peopl. A few records on cha-hua culture exist, but no studies expound the interaction between C. reticulata and traditional culture of ethnic groups. The contribution of traditional culture of different nationalities and regions to the diversity of Camellia reticulate is discussed.

Methods

Ethnobotanical surveys were conducted throughout Central and Western Yunnan to investigate and document the traditional culture related to Camellia reticulata. Five sites were selected to carry out the field investigation. Information was collected using participatory observation, semi-structured interviews, key informant interviews, focus group discussions, and participatory rural appraisal (PRA).

Results

Most of the ancient camellia trees were preserved or saved in the courtyards of old buildings and cultural or religious sites. Religion-associated culture plays an important role in C. reticulata protection. In every site we investigated, we found extensive traditional culture on C. reticulata and its management. These traditional cultures have not only protected the germplasm resources of C. reticulata, but also improved the diversity of Camellia cultivars.

Conclusions

There are abundant and diverse genetic resources of cha-hua, Camellia reticulata in Yunnan. Cha-hua is not only an ornamental flower but also has been endowed with rich spiritual connotation. The influence of traditional culture had improved the introduction and domestication of wild plants, breeding and selection of different varieties, and the propagation and dissemination of the tree in Yunnan. However, either some ancient cha-hua trees or their associated traditional culture are facing various threats. The old cha-hua trees and the ethnic camellia culture should be respected and protected since they have made great contributions in the history, and will make more contributions in the future.

     

Bioactivity,toxicity and detoxification assessment of <Emphasis Type="Italic">Dioscorea bulbifera</Emphasis> L.: a comprehensive review

Dioscorea bulbifera L. (Chinese: Huangdu, common name: air potato) is a traditional herbal medicine in China, and it is also one of the most widely consumed yam species, especially in West Africa. Studies have verified that D. bulbifera is effective in treating a wide range of diseases, such as pharyngitis, goitre, pyogenic skin infections, orchitis and cancer. However, more and more studies have also reported liver and kidney damage caused by D. bulbifera. To promote understanding of the bioactivity, toxicity and methods for detoxification of this medicinal and edible plant, the present article reviews the most valuable recent reports on its phytochemistry and pharmacological effects. The possible reasons for its toxicity include the toxic effects of diosbulbin B and D on hepatocytes, the inhibition of antioxidant enzymes in liver mitochondria, and inhibition of enzymes that ordinarily metabolize the herb’s components. Synergistic compatibility detoxification may help to reduce toxic effects and improve therapeutic effects. More clinical trials are also required to fully achieve its therapeutic potential.     

Low genetic differentiation among altitudes in wild <Emphasis Type="Italic">Camellia oleifera</Emphasis>, a subtropical evergreen hexaploid plant

Camellia oleifera is a subtropical evergreen plant. Cultivated C. oleifera is the most important woody oil crop in China. Wild C. oleifera is an essential genetic resource for breeding. The patterns of genetic differentiation among altitudes/latitudes in wild C. oleifera are still unknown. Camellia oleifera may be predominantly hexaploid. The characteristics of polyploidy may lead to considerable biases in estimates of genetic diversity and differentiation. Our study used C. oleifera as a case study for analysing genetic diversity, structure and differentiation in polyploid plants using simple sequence repeats (SSRs). Wild C. oleifera samples were collected at different altitudes on the Jinggang and Lu mountains of China. The ploidy levels were determined with flow cytometry analysis. Eight highly polymorphic SSRs were used to genotype the samples. Genetic diversity and structure were analysed. Various estimates of genetic differentiation were compared. The flow cytometry results indicated that wild C. oleifera samples were all hexaploid at various altitudes of the Jinggang and Lu mountains. High levels of genetic diversity were found on both the Jinggang and Lu mountains. Genetic structure analyses indicated clear genetic differentiation between the Jinggang and Lu mountains and lower genetic differentiation among altitudes within each mountain. Classical genetic differentiation estimates of F_st failed to discriminate genetic differentiation between and within mountains. The Rho statistic showed a moderate level of genetic differentiation between mountains and lower levels of genetic differentiation within each mountain. Our study demonstrates that Rho is the statistic of choice for estimating genetic differentiation in polyploids.     

Genus <Emphasis Type="Italic">Retama</Emphasis>: a review on traditional uses,phytochemistry, and pharmacological activities

Plants of the genus Retama (Fabaceae) are used in traditional medicine of the Mediterranean Basin as an emetic, purgative, and vermifuge. Certain Retama species are also employed to treat a multitude of disorders, including diabetes, hepatitis, jaundice, sore throat, skin diseases, joint pain, rheumatism, fever, and inflammation. This review deals with updated information on the distribution, botanical characteristics, ethnopharmacology, phytochemistry, pharmacological activities, and toxicity of the Retama species in order to support their therapeutic potential and to provide an input for future research prospects. The Retama species are mainly employed as ethnomedicinal remedies in Mediterranean countries, including Algeria, Egypt, Italy, Lebanon, Libya, Morocco, and Spain. Previous phytochemical studies show a complex composition, rich in carbohydrates (galactomannans), polyols (pinitol), fatty acids, phenolic compounds (genistein, daidzein) and alkaloids (retamine, lupanine). The pharmacological activity of their various extracts has been widely studied, revealing, among others, the anti-microbial, anti-inflammatory, and anti-diabetic effects of these species. The potential toxicity of these medicinal plants has also been discussed. Although recent experimental evidence confirms the pharmacological interest of this genus, further studies are necessary.     

<Emphasis Type="Italic">Origanum</Emphasis> spp.: an update of their chemical and biological profiles

The purpose of this review is to provide an overview of most recent studies about potential pharmaceutical applications of plants belonging to Origanum genus. Oregano is one of the most famous and economically important culinary herbs in the world. The genus Origanum includes more than 70 species mainly distributed around the Mediterranean region. The vernacular name “oregano” is attributed to a vast number of species. O. vulgare L. is the most variable species of the genus and the most commonly known as oregano in most countries. Today, it is generally accepted that oregano is a characteristic flavour produced by a number of plant species that yield carvacrol-rich essential oils. The genus Origanum is characterised by a large morphological and chemical diversity. Because of their several biological activities, such as antimicrobial, expectorant, antispasmodic and carminative, Origanum species have been used in traditional medicine to treat various diseases. The botany and chemotaxonomy of the species are thoroughly reported, along with chemical constituents. The in vitro and in vivo effects of Origanum extracts are presented and discussed.     

Acaricidal property of the essential oil from <Emphasis Type="Italic">Lippia gracilis</Emphasis> against <Emphasis Type="Italic">Tetranychus urticae</Emphasis> and a natural enemy, <Emphasis Type="Italic">Neoseiulus californicus</Emphasis>, under greenhouse conditions

The essential oil from the leaves of Lippia gracilis was investigated for fumigant and residual activity against Tetranychus urticae (Acari: Tetranychidae) and Neoseiulus californicus (Acari: Phytoseiidae). The results were compared to eugenol, Ortus^® and Azamax^®, as positive controls. Gas chromatography (GC) and GC/mass spectrometry analysis enabled the identification of 28 compounds, accounting for 99.1?±?0.6% of the essential oil. The major constituents were carvacrol (61%), p-cymene (11%) and thymol (11%). Mites were more susceptible to the oil in fumigant tests than in residual tests. Among the components, thymol and β-caryophyllene had the greatest fumigant and residual toxicity against T. urticae, respectively. The role of selected constituents (carvacrol, p-cymene, thymol, limonene, β-pinene, 1,8-cineole, terpinolene and β-caryophyllene) in the acaricidal properties of the L. gracilis essential oil is also discussed. Fumigant and residual effects of Lippia oil were more selective than eugenol with regard to a natural enemy of T. urticae, Neoseiulus californicus. Experiments under greenhouse conditions demonstrated greater toxicity of the Lippia oil in comparison to the positive control at 24, 48 and 72 h after treatment. The results suggest that Lippia oil is a good candidate for the formulation of a botanical acaricide for the integrated management of T. urticae.     

Metabolomics reveals immunomodulation as a possible mechanism for the antibiotic effect of <Emphasis Type="Italic">Persicaria capitata</Emphasis> (Buch.-Ham. ex D. Don) H.Gross

Introduction

In spite of advances in antibiotics, urinary tract infection (UTI) is still among the most common reasons for antibiotic medication worldwide. Persicaria capitata (Buch.-Ham. ex D. Don) H.Gross (P. capitata) is a herbal medicine used by the Miao people in China to treat UTI. However studies of its mechanism are challenging, owing to the complexity of P. capitata with multiple constituents acting on multiple metabolic pathways.

Objective

The objective of this study was to explore the working mechanism of P. capitata on urinary tract infection.

Methods

Relinqing® granule, which is solely made from aqueous extracts of the whole P. capitata plant, was used in this study. Urine metabolomics based on gas chromatography-mass spectroscopy was employed to assess the metabolic changes caused by administration of Relinqing® granule in a UTI mouse model. Female specific-pathogen-free Kunming mice were divided into control group (mock infection, saline treatment), model group (E.coli infection, saline treatment), Relinqing® group (E.coli infection, Relinqing® granule treatment), ciprofloxacin group (E.coli infection, ciprofloxacin treatment), and sham-Relinqing® group (no surgery, Relinqing® granule treatment).

Results

The results showed that after the treatments, urine levels of itaconic acid in Relinqing® group increased by 4.9 fold and 11.3 fold compared with model and ciprofloxacin groups respectively. Itaconic acid is an endogenous antibacterial metabolite produced by macrophages, which also functions as a checkpoint for metabolic reprogramming of macrophage.

Conclusion

Our findings suggest that this herbal medicine can cure urinary tract infection through modulation of immune system.

     

Extrafloral nectaries of four varieties of <Emphasis Type="Italic">Chamaecrista ramosa</Emphasis> (Vogel) H.S.Irwin &amp; Barneby (Fabaceae): anatomy,chemical nature,mechanisms of nectar secretion,and elimination

Considering the importance of extrafloral nectaries (EFNs) in Fabaceae, the objectives of this research were to analyze (1) the anatomical and histochemical characteristics of the EFNs of Chamaecrista ramosa var. ramosa, C. ramosa var. curvifoliola, C. ramosa var. parvifoliola, and C. ramosa var. lucida and (2) the ultrastructure of the EFNs of C. ramosa var. ramosa. Standard techniques in plant anatomy and transmission electron microscopy were used. The anatomical analyses confirmed the characteristics described for extrafloral nectaries, evidencing three well-defined regions: epidermis, nectariferous, and subnectariferous parenchymas. Carbohydrates, proteins, pectins/mucilages, and lipids were detected by histochemical analyzes in all varieties. The ultrastructure of the EFNs of C. ramosa var. ramosa allowed the observation of microchannels at the external periclinal cell walls of the epidermis covering the secretory region. The nectariferous and subnectariferous parenchyma cells have periplasmic spaces, large plastids containing starch grains and plastoglobules, mitochondria, developed endoplasmic reticulum, large vacuoles with electron-dense contents, and membrane residues may be associated with the vacuole, suggesting the occurrence of autophagic processes. The anatomical, histochemical, and ultrastructural patterns revealed characteristics that confirm the glands of C. ramosa as extrafloral nectaries and suggest the eccrine mechanism of secretion.     

Construction and characterization of a bacterial artificial chromosome library for <Emphasis Type="Italic">Camellia sinensis</Emphasis>

Tea is a popular and natural non-alcoholic beverage, and is produced from fresh leaves of Camellia sinensis. Tea leaves contain many bioactive compounds that have significant health benefits. We constructed a high quality bacterial artificial chromosome (BAC) library by using the fresh petals of C. sinensis “Shuchazao” for genome sequencing and improvement of genomic assembly. BAC library is still a significant tool for studies of functional genomes and preservation of precious genetic resources. The BAC library contains 161,280 clones with an average insert size of 113 kb, which represents approximately 6.2-fold coverage of haploid genome equivalents of C. sinensis. We characterized 20 complete BAC clones and 738 BAC end sequences (BESs) ranging from 105 to 917 bp. In addition, we predicted cis-regulatory elements of LAR (leucoanthocyanidin reductase), TCS (caffeine synthase), and TS (theanine synthetase) involved in tea characteristic metabolite synthesis and identified a larger number of light-responsive cis-acting elements in these three genes. Meanwhile, we analyzed alternative splicing of these three genes. Furthermore, 12 pairs of SSR primers were successfully amplified in tea plant DNA. The tea BAC library was a critical resource to accomplish de novo whole-genome sequencing, accelerate gene discovery and enhance molecular breeding of C. sinensis.     

Assessing the maternal origin in the polyploid complex of <Emphasis Type="Italic">Camellia reticulata</Emphasis> based on the chloroplast <Emphasis Type="Italic">rpl</Emphasis>16 intron sequences: implications for camellia cross breeding

Camellia reticulata is a well-known woody ornamental species endemic to Southwest China. It represents a polyploid complex with diploids, allotetraploids, and allohexaploids. The parentage of the allotetraploids and allohexaploids has been reported by genomic in situ hybridization, but the maternal parents still remain unknown. In this study, sequences of the chloroplast rpl16 intron of 105 cultivars of C. reticulata and 7 congeneric species were used to infer the maternal origin of the allopolyploids. The results showed that (1) the allotetraploids were derived from C. pitardii as the maternal parental species and the diploid C. reticulata as the paternal parental species; (2) the allohexaploid C. reticulata was derived from the allotetraploid C. reticulata as the maternal parent and C. saluenensis as the paternal parent; and (3) the C. reticulata cultivars were derived from hexaploid C. reticulata as the maternal parents. These results indicated that C. pitardii, the allotetraploid and allohexaploid C. reticulata may serve as good potential maternal parents for the cross breeding of Camellia.     

<Emphasis Type="Italic">Rhodiola rosea</Emphasis> L.: from golden root to green cell factories

Rhodiola rosea L. is a worldwide popular plant with adaptogenic activities that have been and currently are exploited in the traditional medicine of many countries, as well as, examined in a number of clinical trials. More than 140 chemical structures have been identified which belong to several natural product classes, including phenylpropanoid glycosides, phenylethanoids, flavonoids and essential oils, and are mainly stored in the rhizomes and the roots of the plant. A number of mechanisms contribute to the adaptogenic activities of R. rosea preparations and its phytochemical constituents. Among them, the intrinsic inducible mammalian stress responses and their effector proteins, such as heat shock protein 70 (Hsp70), are the most prominent. Due to its popular medicinal use, which has led to depletion of its natural habitats, R. rosea is now considered as endangered in most parts of the world. Conservation, cultivation and micropropagation are all implemented as potential preservation strategies. A number of in vitro systems of R. rosea are being developed as sources of pharmaceutically valuable secondary metabolites. These are greatly facilitated by advances in elucidation of the biosynthetic pathways and the enzymes, which catalyse the production of these secondary metabolites in the plant. In addition, biotechnological approaches show promise towards achieving sustainable production of R. rosea secondary metabolites.     

The genus <Emphasis Type="Italic">Lindera</Emphasis>: a source of structurally diverse molecules having pharmacological significance

Lindera plants not only have good ornamental and economic uses but also have great medicinal and therapeutic values. The genus Lindera consists of approximately 100 species that are widely distributed in tropical and subtropical areas throughout the world. This extensive geographical distribution allows Lindera plants to produce diverse secondary metabolites having novel structures. Phytochemical investigations have shown that Lindera plants produce 341 constituents, including sesquiterpenoids, alkaloids, butanolides, lucidones, flavonoids, and phenylpropanoids. Moreover, some Lindera plants show significant chemotaxonomic reference under family Lauraceae and tribe Litseae. Although Lindera plants have various pharmacological and biological properties, their anticancer, antihypertensive, anti-inflammatory, and analgesic properties have been focused in many studies. Butanolides and lucidones have shown great potential in developing anticancer agents while aporphine alkaloids have shown great potential in developing antiarthritic and antinociceptive agents. However, these compounds need to be assessed further by performing in-depth and systematic research.     

<Emphasis Type="Italic">Fusarium</Emphasis> Infection Causes Phenolic Accumulations and Hormonal Disorders in <Emphasis Type="Italic">Orobanche</Emphasis> spp.

The physiological effects of Fusarium oxysporum on in-root parasitic weed, Orobanche spp. (broomrape) with references to change in plant hormones and secondary plant constituents were investigated. The levels of IAA, GA, ABA and JA in the experimental group were significantly lower than those in the control group, while the level of SA was higher in the experimental group. In secondary metabolic studies, the quantities of various phenols were measured in the two groups and catechin, syringic acid and p-coumaric acid amounts were significantly higher in the experimental group than in the control group, unlike gallic acid which have a lower amount. Consequently, in the light of all data, it was concluded that Fusarium oxysporum (1) causes heavy hormonal disorder, (2) triggered only SA-mediated defense and (3) induced intensively accumulation of phenolic substances in orobanche. Fusarium oxysporum causes lethal physiological damage on Orobanche spp.     

HPLC fractionation and pharmacological assessment of green tea seed saponins for antimicrobial,anti-angiogenic and hemolytic activities

Herbal medicinal products have proven to be safe, economical and effective alternatives to synthetic chemical pharmaceuticals. The green tea plant (Camellia sinensis) is of profound medicinal value due to the presence of potent bioactive constituents. The purpose of the present work is to investigate saponins from green tea seeds for potential use as anti-angiogenic, antimicrobial, and hemolytic agents. Green tea seed saponins were separated into six fractions by reverse phase HPLC. The presence of three aglycone chains in the saponins of each fraction was confirmed by acid hydrolysis. Anti-angiogenic activity was evaluated using saponin fractions at concentrations in the range of 2.5 ~ 25 μg/mL. Antimicrobial activity was evaluated by thin-layer chromatography (TLC) using E. coli; S. mutans, a zoonotic Salmonella species and the fungal strain, A. niger. Saponin fractions were more potent against E. coli (gram negative bacteria) than against S. mutans (gram positive bacteria) and strongly inhibited six strains of zoonotic Salmonella. Green tea saponins also showed potent anti-angiogenic effects. All saponin fractions exhibited hemolytic activity. Our results confirm that green tea saponins have antimicrobial, anti-angiogenic, and hemolytic activities; indicating their potential as natural pharmaceutical products.