From single- to multi-omics: future research trends in medicinal plants.

Medicinal plants are the main source of natural metabolites with specialised pharmacological activities and have been widely examined by plant researchers. Numerous omics studies of medicinal plants have been performed to identify molecular markers of species and functional genes controlling key biological traits, as well as to understand biosynthetic pathways of bioactive metabolites and the regulatory mechanisms of environmental responses. Omics technologies have been widely applied to medicinal plants, including as taxonomics, transcriptomics, metabolomics, proteomics, genomics, pangenomics, epigenomics and mutagenomics. However, because of the complex biological regulation network, single omics usually fail to explain the specific biological phenomena. In recent years, reports of integrated multi-omics studies of medicinal plants have increased. Until now, there have few assessments of recent developments and upcoming trends in omics studies of medicinal plants. We highlight recent developments in omics research of medicinal plants, summarise the typical bioinformatics resources available for analysing omics datasets, and discuss related future directions and challenges. This information facilitates further studies of medicinal plants, refinement of current approaches and leads to new ideas.

Secondary metabolites from the fungus Cladosporium xylophilum.

A new cladosporol derivative xylophilum A (1), together with 10 known compounds (2-11), were isolated from the rice fermentation of the fungus Cladosporium xylophilum. Their structures were established by extensive spectroscopic methods and comparison of their NMR data with literatures. The antimicrobial activity of compound 1 against 11 kinds of pathogenic microbial was evaluated, but no significant activity was found (MIC >100 µg/ml).

Rho2 involved in development, stress response and pathogenicity of Fusarium oxysporum.

Rho GTPases regulate the activity of cell wall biosynthesis, actin assembly and polar cell secretion. However, the function of Rho GTPase in filamentous fungi is poorly understood. To understand the role of Rho2 GTPase in Fusarium oxysporum, which is one of root rot pathogens of Panax notoginseng, △rho2 mutant was constructed. Phenotypes of △rho2, including conidiation, germination of spores, stresses (osmotic-, cell membrane-, cell wall disturbing-, metal-, and high temperature-) tolerance and pathogenicity were analyzed. The results showed that the growth of △rho2 was destroyed under cell wall disturbing stress and high temperature stress, suggesting that Rho2 regulated the response of F. oxysporum to cell wall synthesis inhibitors and high temperature stress. Germination of spores and pathogenicity to P. notoginseng were reduced in △rho2 mutant. Western blot results showed that rho2 deletion increased the phosphorylation level of Mpk1. To identify genes regulated by Rho2, transcriptome sequencing was carried out. 2477 genes were identified as upregulated genes and 2177 genes were identified as downregulated genes after rho2 was deleted. These genes provide clues for further study of rho2 function.

[Physiological and biochemical mechanisms of brassinosteroid in improving anti-cadmium stress ability of Panax notoginseng].

In this study, the effect of brassinosteroid(BR) on the physiological and biochemical conditions of 2-year-old Panax notoginseng under the cadmium stress was investigated by the pot experiments. The results showed that cadmium treatment at 10 mg·kg~(-1) inhibited the root viability of P. notoginseng, significantly increased the content of H_2O_2 and MDA in the leaves and roots of P. noto-ginseng, caused oxidative damage of P. notoginseng, and reduced the activities of SOD and CAT. Cadmium stress reduced the chlorophyll content of P. notoginseng, increased leaf F_o, reduced F_m, F_v/F_m, and PIABS, and damaged the photosynthesis system of P. notoginseng. Cadmium treatment increased the soluble sugar content of P. notoginseng leaves and roots, inhibited the synthesis of soluble proteins, reduced the fresh weight and dry weight, and inhibited the growth of P. notoginseng. External spray application of 0.1 mg·L~(-1) BR reduced the H_2O_2 and MDA content in P. notoginseng leaves and roots under the cadmium stress, alleviated cadmium-induced oxidative damage to P. notoginseng, improved the antioxidant enzyme activity and root activity of P. notoginseng, increased the content of chlorophyll, reduced the F_o of P. notoginseng leaves, increased F_m, F_v/F_m, and PIABS, alleviated the cadmium-induced damage to the photosynthesis system, and improved the synthesis ability of soluble proteins. In summary, BR can enhance the anti-cadmium stress ability of P. notoginseng by regulating the antioxidant enzyme system and photosynthesis system of P. notoginseng under the cadmium stress. In the context of 0.1 mg·L~(-1) BR, P. notoginseng can better absorb and utilize light energy and synthesize more nutrients, which is more suitable for the growth and development of P. notoginseng.

[Effects of propiconazole on physiological and biochemical properties of Panax notoginseng and dietary risk assessment].

To study the residue and dietary risk of propiconazole in Panax notoginseng and the effects on physiological and bioche-mical properties of P. notoginseng, we conducted foliar spraying of propiconazole on P. notoginseng in pot experiments. The physiolo-gical and biochemical properties studied included leaf damage, osmoregulatory substance content, antioxidant enzyme system, non-enzymatic system, and saponin content in the main root. The results showed that at the same application concentration, the residual amount of propiconazole in each part of P. notoginseng increased with the increase in the times of application and decreased with the extension of harvest interval. After one-time application of propiconazole according to the recommended dose(132 g·hm~(-2)) for P. ginseng, the half-life was 11.37-13.67 days. After 1-2 times of application in P. notoginseng, propiconazole had a low risk of dietary intake and safety threat to the population. The propiconazole treatment at the recommended concentration and above significantly increased the malondialdehyde(MDA) content, relative conductivity, and osmoregulatory substances and caused the accumulation of reactive oxygen species in P. notoginseng leaves. The propiconazole treatment at half(66 g·hm~(-2)) of the recommended dose for P. ginseng significantly increased the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) in P. notoginseng leaves. The propiconazole treatment at 132 g·hm~(-2) above inhibited the activities of glutathione reductase(GR) and glutathione S-transferase(GST), thereby reducing glutathione(GSH) content. Proconazole treatment changed the proportion of 5 main saponins in the main root of P. notoginseng. The treatment with 66 g·hm~(-2) propiconazole promoted the accumulation of saponins, while that with 132 g·hm~(-2) and above propiconazole significantly inhibited the accumulation of saponins. In summary, using propiconazole at 132 g·hm~(-2) to prevent and treat P. notoginseng diseases will cause stress on P. notoginseng, while propiconazole treatment at 66 g·hm~(-2) will not cause stress on P. notoginseng but promote the accumulation of saponins. The effect of propiconazole on P. notoginseng diseases remains to be studied.

De novo and comparative transcriptomic analysis explain morphological differences in Panax notoginseng taproots.

BACKGROUND: Panax notoginseng (Burk.) F. H. Chen (PN) belonging to the genus Panax of family Araliaceae is widely used in traditional Chinese medicine to treat various diseases. PN taproot, as the most vital organ for the accumulation of bioactive components, presents a variable morphology (oval or long), even within the same environment. However, no related studies have yet explained the molecular mechanism of phenotypic differences. To investigate the cause of differences in the taproot phenotype, de novo and comparative transcriptomic analysis on PN taproot was performed. RESULTS: A total of 133,730,886 and 114,761,595 paired-end clean reads were obtained based on high-throughput sequencing from oval and long taproot samples, respectively. 121,955 unigenes with contig N50 = 1,774 bp were generated by using the de novo assembly transcriptome, 63,133 annotations were obtained with the BLAST. And then, 42 genes belong to class III peroxidase (PRX) gene family, 8 genes belong to L-Ascorbate peroxidase (APX) gene family, and 55 genes belong to a series of mitogen-activated protein kinase (MAPK) gene family were identified based on integrated annotation results. Differentially expressed genes analysis indicated substantial up-regulation of PnAPX3 and PnPRX45, which are related to reactive oxygen species metabolism, and the PnMPK3 gene, which is related to cell proliferation and plant root development, in long taproots compared with that in oval taproots. Furthermore, the determination results of real-time quantitative PCR, enzyme activity, and H2O2 content verified transcriptomic analysis results. CONCLUSION: These results collectively demonstrate that reactive oxygen species (ROS) metabolism and the PnMPK3 gene may play vital roles in regulating the taproot phenotype of PN. This study provides further insights into the genetic mechanisms of phenotypic differences in other species of the genus Panax.

Melatonin functions in priming of stomatal immunity in Panax notoginseng and Arabidopsis thaliana.

Melatonin (MT) plays important roles in plant disease response, but the mechanisms are largely unknown. Here, we show that MT functions in stomatal immunity in Panax notoginseng and Arabidopsis thaliana. Biochemical analyses showed that MT-induced stomatal closure plays a prominent role in preventing invasion of bacteria Pseudomonas syringe pv. tomato (Pst) DC3000 via activation of mitogen-activated protein kinase (MAPK) and NADPH oxidase-mediated reactive oxygen species production in P. notoginseng. The first putative phytomelatonin receptor 1 (PMTR1) is a plasma membrane protein required for perceiving MT signaling in stomatal closure and activation of MAPK. Biochemical and genetic tests found PMTR1 is essential for flg22- and MT-induced MAPK activation in a heterotrimeric GTP-binding protein Gα subunit GPA1-independent manner. GPA1 functions in the same genetic pathways of FLS2/BAK1 (Flagellin Sensing 2/Brassinosteroid Insensitive 1-associated kinase 1)- as well as PMTR1-mediated flg22 and MT signaling in stomatal closure. The stomata in pmtr1 are insensitive to MT and flg22, but the application of MT induces stomatal closure and reduces the bacterial growth in fls2 and bak1 plants, indicating that PMTR1 might be a downstream signaling component in FLS2- and BAK1-mediated stomatal immunity. In summary, our results (i) demonstrate that phytomelatonin functions in the priming of stomatal immunity and (ii) provide insights into the phytomelatonin signaling transduction pathway.

Novel Deep Eutectic Solvent-Hydrogel Systems for Synergistic Transdermal Delivery of Chinese Herb Medicine and Local Treatments for Rheumatoid Arthritis.

In this study, a novel hydrogel system incorporating an amino acid-based deep eutectic solvent (DES) was prepared, and the skin-permeation enhancement of traditional Chinese herb medicine was evaluated using "sanwujiaowan" extract as the model formula. Briefly, a DES-extract complex was constructed by co-heating the herb formula extracts with the amino acid as the hydrogen receptor and citric acid as the hydrogen donor. The DES-extract complex demonstrated excellent dissolution and skin permeability of the complicated ingredients in the extracts. Consequently, the DES-extract complex was introduced to a hydrogel system, which showed better mechanical properties and viscoelasticity performance. Using a collagen-induced arthritis rat model, the DES-hydrogels exerted an enhanced therapeutic effect that significantly reduced the inflammatory response with systemic toxicity of the extracts. Therefore, our work suggests a novel strategy for synergistic transdermal delivery of Chinese herb medicine and local treatments for rheumatoid arthritis.

An MYB Transcription Factor Modulates Panax notoginseng Resistance Against the Root Rot Pathogen Fusarium solani by Regulating the Jasmonate Acid Signaling Pathway and Photosynthesis.

Root rot of Panax notoginseng, a precious Chinese medicinal plant, seriously impacts its sustainable production. However, the molecular regulatory mechanisms employed by P. notoginseng against root rot pathogens, including Fusarium solani, are still unclear. In this study, the PnMYB2 gene was isolated, and its expression was affected by independent treatments with four signaling molecules (methyl jasmonate, ethephon, salicylic acid, and hydrogen peroxide) as assessed by quantitative real-time PCR. Moreover, the PnMYB2 expression level was induced by F. solani infection. The PnMYB2 protein localized to the nucleus and may function as a transcription factor. When overexpressed in transgenic tobacco, the PnMYB2 gene conferred resistance to F. solani. Jasmonic acid (JA) metabolism and disease resistance-related genes were induced in the transgenic tobacco, and the JA content significantly increased compared with in the wild type. Additionally, transcriptome sequencing, Kyoto Encyclopedia of Genes and Genomes annotation enrichment, and metabolic pathway analyses of the differentially expressed genes in the transgenic tobacco revealed that JA metabolic, photosynthetic, and defense response-related pathways were activated. In summary, PnMYB2 is an important transcription factor in the defense responses of P. notoginseng against root rot pathogens that acts by regulating JA signaling, photosynthesis, and disease-resistance genes.

The remediation effects of microbial organic fertilizer on soil microorganisms after chloropicrin fumigation.

Soil fumigation with chloropicrin (CP) is an effective means of overcoming continuous cropping obstacles (CCO) in Panax notoginseng and improving its yield and quality. CP fumigation can change the microbial community of soil. Therefore, a key step after CP fumigation is the rapid restoration of soil microorganisms and the promotion of beneficial microorganism proliferation as the dominant flora. In this study, continuously cropped soil of P. notoginseng was fumigated with CP, and general organic fertilizer (GOF) or microbial organic fertilizer (MOF) was used to restore soil microorganisms after fumigation. Soil physical and chemical properties, soil microorganisms, and quality of P. notoginseng were investigated. The application of MOF and GOF after CP fumigation promoted increases in soil nitrogen (9.88% and 8.21%, respectively), phosphorus (21.39% and 11.57%, respectively), potassium (7.99% and 2.75%, respectively), and the quality of P. notoginseng; it also promoted the accumulation of saponins in the main roots (23.62% and 9.12%, respectively). Application of MOF and GOF can restore the diversity of microorganisms in the soil. MOF increased the relative abundance of the beneficial soil microorganisms Glomeromycota, Mortierellomycota, Humicola and Bacillus, thereby lowering the relative abundance of the harmful Ascomycota and Fusarium relative to GOF. In summary, CP fumigation reduces the diversity of microorganisms in the soil. The addition of organic fertilizer can promote microbial diversity and increase the relative abundance of beneficial species. Moreover, the promotion effect of MOF is better than that of GOF, thereby improving soil fertility and ultimately promoting the quality and yield of P. notoginseng.

Rapid determination and dietary intake risk assessment of 249 pesticide residues in Panax notoginseng.

UPLC-MS/MS and GC-MS/MS were used to establish a method to simultaneously determine various pesticide residues in Panax notoginseng. Results showed that the limits of detection of 249 pesticides were all 5-10 µg/kg. The detection rate of pesticides in 121 P. notoginseng samples was 93.39%, and 19 pesticides were detected. According to the US Code of Federal Regulations, the Chinese Pharmacopoeia recommended algorithm, and the Japanese "positive list system", the pass rates of pesticide residues were 100%, 99.17%, and 89.26%, respectively. The chronic risk quotient (ADI%) and acute risk quotient (ARfD%) of P. notoginseng were 0.00-0.12% and 0.00-0.15%, respectively. In summary, the detection method established in this study can be used for routine analysis of various P. notoginseng pesticide residues. The pesticide residues in the main root samples of P. notoginseng were at a safe level and unlikely pose health risks to consumers.

First report of a Panax notoginseng leaf disease caused by Alternaria alternata in China.

Panax notoginseng (Burk.) F. H. Chen is a perennial plant species in the family Araliaceae, and its roots and rhizome are precious materials for the production of traditional Chinese medicine. From April to June, 2018, new disease symptoms were detected on the mature leaves of 2- and 3-year-old Panax notoginseng (P. notoginseng) in Wenshan Autonomous Prefecture, Yunnan Province, China, and the disease incidence was about 10%-15% among the analyzed fields (3.6 ha, 23°49'46.99″ N, 104°06'12.99″ E, 1,631 m elevation). The diseased leaves had dark brown necrotic lesions (0.9-2.5 × 1.0-3.5 cm) and curled downward. As the disease progressed, the necrosis gradually spread along the vein to other leaf parts, eventually covering the whole leaf. In the late disease stage, the whole leaf was decayed and yellowed. For pathogen isolation, infected leaves (n=20) were surface sterilized in 1% sodium hypochlorite and washed with sterilized distilled water for 3 mins before being cut into smaller pieces (~1cm2), then placed onto potato dextrose agar (PDA) medium and incubated at 28°C under aseptic conditions for 3 days. The hypha around leaf discs were transferred onto the new PDA. A total of 20 colonies (SQ1~20) were obtained and purified by single spore culture for morphological characterization and molecular biological identification. The colonies of all isolates were nearly round, grayish white at the initial stage, and then turned to grayish brown. In addition, microscopic examination (100× magnification) of 20 isolates revealed dark, septate, and sparsely branched conidiophores as well as dark brown conidia with short conical beaks at their tip. Additionally, conidia (solitary or in short chains) were typically oval or club-shaped and had 0-2 longitudinal septa and 2-4 transverse septa (20-35 × 8-12 µm) (n = 50). Moreover, the conidia had a smooth or verrucose surface. Their morphological characteristics were similar to those descriptions given for members of section Alternaria by Lawrence et al. (2016). In order to further identify pathogenic species, genomic DNA was extracted from the colonies (SQ1~20) using a modified cetyltrimethylammonium bromide (CTAB) method (Loganathan et al. 2014). The sequences of internal transcribed spacer regions of ribosomal DNA (rDNA ITS) and partial RNA polymerase II second subunit gene (RPB2) were amplified by PCR using fungal universal primers ITS1/ITS4 (White et al. 1990) and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. The DNA sequencing shows that ITS sequences from 20 isolates were totally same, and so did the RPB2 sequences (supplementary material). BLASTN analysis of NCBI database indicated that the RPB2 and ITS sequences have the highest nucleotide homology to A. Alternata ITS (MW008974) and RPB2 (LC132700), respectively. These two gene sequences were submitted to GenBank [Accession numbers ON075466 (ITS) and OP572232 (RPB2)]. Phylogenetic trees based on the combined ITS and RPB2 sequences were constructed by maximum parsimony method. The referenced ITS and RPB2 sequences of Alternaria were from three published articles (Rama et al. 2020; Sun et al. 2021; Wee et al. 2006). Phylogenetic analysis revealed that this isolate was clustered with A. alternata. Therefore, the morphology-based preliminary identification was verified by the phylogenetic analysis, and the isolate from diseased P. notoginseng leaves was A. alternata. To confirm its pathogenicity, the fungal isolate was assessed with 40 1-year-old healthy P. notoginseng plants in a greenhouse. Among them, the leaves of 20 of P. notoginseng plants were wounded using a sterile needle (seven or eight wounds per leaf) and then inoculated with 1mL conidial suspension (1 × 106 conidia/mL) prepared from 7-day-old fungal cultures grown on PDA medium. The inoculated plants were covered with plastic bags at 25°C for 24 h to maintain humidity, and then transferred to the greenhouse maintained at 28°C with a 16-h day/8-h night cycle and continuous misting. The other 20 control plants were only wounded and sprayed with sterile water. Typical necrotic lesions were detected on all of the inoculated P. notoginseng leaves cultivated in the greenhouse for 1 week post-inoculation. As the disease continued to develop, the necrotic lesions enlarged, and the infected leaves turned yellow and withered. These symptoms were similar to those observed on the naturally infected P. notoginseng. In contrast, the mock-inoculated control plants remained healthy. Furthermore, the fungus re-isolated from the infected P. notoginseng leaves in the pot experiment had similar morphological characteristics as the original strain. In addition, its genomic DNA was extracted for PCR analysis of ITS and RPB2 sequences, and the following DNA sequencing shows that the two DNA sequences were same as those of isolates SQ1~20, which confirmed that the re-isolated fungus was A. alternata. To the best of our knowledge, this is the first report of A. alternata causing a P. notoginseng leaf disease in China.

Four New Sesquiterpenoids from the Rice Fermentation of Antrodiella albocinnamomea.

Albocimea B-E (1-4), four new sesquiterpenoids, and four known compounds, steperoxide A (5), dankasterone (6), 1H-indole-3-carboxylic acid (7), and (+)-formylanserinone B (8), were isolated from the rice fermentation of the fungus Antrodiella albocinnamomea. The structures of new compounds were elucidated by comprehensive spectroscopic techniques, the planar structures of new compounds were determined by comprehensive spectroscopic techniques, and their absolute configurations were confirmed via gauge-independent atomic orbital calculations (GIAO), calculation of the electronic circular dichroism (ECD), and optical rotation (OR). These were determined by spectroscopic data analysis.

Production of Minor Ginsenosides from Panax notoginseng Flowers by Cladosporium xylophilum.

Panax notoginseng flowers have the highest content of saponins compared to the other parts of Panax notoginseng, but minor ginsenosides have higher pharmacological activity than the main natural ginsenosides. Therefore, this study focused on the transformation of the main ginsenosides in Panax notoginseng flowers to minor ginsenosides using the fungus of Cladosporium xylophilum isolated from soil. The main ginsenosides Rb1, Rb2, Rb3, and Rc and the notoginsenoside Fa in Panax notoginseng flowers were transformed into the ginsenosides F2 and Rd2, the notoginsenosides Fd and Fe, and the ginsenoside R7; the conversion rates were 100, 100, 100, 88.5, and 100%, respectively. The transformation products were studied by TLC, HPLC, and MS analyses, and the biotransformation pathways of the major ginsenosides were proposed. In addition, the purified enzyme of the fungus was prepared with the molecular weight of 66.4 kDa. The transformation of the monomer ginsenosides by the crude enzyme is consistent with that by the fungus. Additionally, three saponins were isolated from the transformation products and identified as the ginsenoside Rd2 and the notoginsenosides Fe and Fd by NMR and MS analyses. This study provided a unique and powerful microbial strain for efficiently transformating major ginsenosides in P. notoginseng flowers to minor ginsenosides, which will help raise the functional and economic value of the P. notoginseng flower.

[Contributions and strategies of eco-agriculture of Chinese medicine services for carbon dioxide peaking and carbon neutrality].

Carbon dioxide peaking and carbon neutrality have become hot issues of political and economic activities in China and abroad. The structure and development of various industries in China will be profoundly affected in the process of accomplishing "Dual Carbon" goals. Eco-agriculture of Chinese medicine(EACM) highlights the balance and sustainable development of the ecosystem while producing high-quality medicinal materials. With chemically synthesized fertilizers, pesticides, and growth regulators prohibited, EACM emphasizes the recycling of agricultural and sideline products and the reduction of waste output, which results in the minimal negative impact on the ecological environment. Therefore, it is typical agriculture with low-carbon sources and high-carbon sinks. This study reviewed the mechanism and potential of EACM in carbon dioxide peaking and carbon neutrality, analyzed the specific ways of EACM in reducing carbon sources and increasing carbon sinks based on the typical ecological planting pattern, and proposed the point of view to strengthen EACM as well as the "Dual Carbon" theory and research methods, so as to direct low-carbon and efficient deve-lopment. Furthermore, this study advocated to comprehensively promote the transformation of Chinese medicine production from chemical agriculture to eco-agriculture to improve the comprehensive benefits of contribution rate of carbon neutrality, explore and establish carbon sink compensation mechanism to ensure the sustainable and healthy development of EACM, and strengthen the training of EACM and "Dual Carbon" theory and technologies to continuously improve the capacity of EACM in sustainable development. This study is expected to provide a reference for the development of ecological functions in EACM and the development of economic functions through ecological functions.

[Effects of chloropicrin fumigation on soil and growth and development of Panax notoginseng].

The continuous cropping obstacle of Panax notoginseng is serious, and effective control measures are lacking. Soil disinfection with chloropicrin(CP) has been proven to be effective in reducing the obstacles to continuous cropping of other crops. In order to ascertain the effect of CP in the continuous cropping of P. notoginseng, this paper explored the influences of CP at different treatment concentrations(0,30,40,50 kg/Mu, 1 Mu≈667 m~2) on soil macro-element nutrients, soil enzyme activity, growth and development of P. notoginseng, and the accumulation of medicinal components. The results showed that CP fumigation significantly increased the content of total nitrogen, alkali-hydrolyzable nitrogen, ammonium nitrogen, nitrate nitrogen, and available phosphorus in the soil, but it had no significant effect on potassium content. The soil protease activity showed a trend of first increasing and then decreasing with the prolonging of the treatment time. Both the soil urease and acid phosphatase activities showed a trend of first decreasing and then increasing with the prolonging of the treatment time. The higher the CP treatment concentration was, the lower the urease and acid phosphatase activities would be in the soil. The protease activity was relatively high after CP40 treatment, which was better than CP30 and CP50 treatments in promoting the nitrogen-phosphorus-potassium accumulation in P. notoginseng. The seedling survival rates after CP0, CP30, CP40, and CP50 tratments in October were 0, 65.56%, 89.44%, and 83.33%, respectively. Compared with the CP30 and CP50 treatments, CP40 treatment significantly facilitated the growth and development of P. notoginseng, the increase in fresh and dry weights, and the accumulation of root saponins. In summary, CP40 treatment accelerates the increase in soil nitrogen and phosphorus nutrients and their accumulation in P. notoginseng, elevates the seedling survival rate of P. notoginseng, enhances the growth and development of P. notoginseng, and promotes the accumulation of medicinal components. CP40 treatment is therefore recommended in production.

[Research progress on pesticide residues of Panax notoginseng].

Panax notoginseng is a perennial Chinese medicinal plant, which has serious continuous cropping obstacles and is prone to a variety of diseases and insect pests during the growth process. At present, the prevention and control of pests and diseases is mainly carried out through chemical pesticides, and the consequent pesticide residues of P. notoginseng have attracted much attention. This study reviewed the types and detection methods of pesticide residues in P. notoginseng from 1981 to 2021, and compared the limits of pesticide residues in P. notoginseng in China and abroad to provide a reference for rational application of pesticides in P. notoginseng and quality control of medicinal materials, thereby promoting the sustainable development of the P. notoginseng industry in China. Currently, there are only 40 published papers on pesticide residues of P. notoginseng, which is indicative of a serious problem of insufficient research. At present, hundreds of pesticide residues in P. notoginseng can be detected simultaneously by using chromatography-tandem mass spectrometry. The pesticides detected have gradually changed from early prohibited ones, such as dichlorodiphenyl trichloroethane(DDT), benzene hexachloride(BHC), and parathion, to low toxic ones(e.g., dimethomorph, procymidone, propicona-zole, and difenoconazole). The dietary risk from pesticide residues in P. notoginseng is low, which would not cause harm to consu-mers. This study concluded that in the future, the development of the quality standard for pesticide residues of P. notoginseng should be actively carried out. To increase the pesticides used in actual production in the quality standard based on the existing ones and to guide farmers to use pesticides scientifically will be the focus of future work.

Novel fluorescent nitrogen-doped carbon dots derived from Panax notoginseng for bioimaging and high selectivity detection of Cr6.

Carbon dots (CDs) and photoluminescent carbon dots (Pn-CDs) are promising nanomaterials due to their bioimaging applications and have attracted considerable attention because of their excellent stability, good biocompatibility, and low biotoxicity. Here, the Pn-CDs and highly fluorescent nitrogen-doped CDs (Pn N-CDs) derived from Panax notoginseng were successfully synthesized by a simple hydrothermal method. Pn N-CDs exhibit optical properties and stability superior to those of Pn-CDs and can be better used as fluorescent dyes and probes in biological imaging. The obtained Pn N-CDs can be effectively applied to the imaging of bacteria, fungi, plant cells, and protozoa. In addition, Pn N-CDs can perform specific staining on the membranes of all tested cells. The in vivo imaging of mice revealed that Pn N-CDs exhibit nontoxicity and good biocompatibility and biodistribution. Furthermore, Pn N-CDs can be utilized as fluorescent probes for the rapid and highly selective detection of Cr6+. Hence, a simple, cost-effective, scalable, and green synthetic approach based on traditional Chinese medicine-derived CDs can be used to develop biolabeling, membrane targeting, and optical sensing probes.

Potassium enhances cadmium resistance ability of Panax notoginseng by brassinolide signaling pathway-regulated cell wall pectin metabolism.

The mechanism of how potassium (K) attenuates cadmium (Cd)-induced demethylation and anabolism of cell wall (CW) pectin through the brassinolide (BR) signaling pathway was verified in Panax notoginseng (Burk.). The P. notoginseng pectin methylesterase gene (PnPME1) was cloned and functionally verified in tobacco. Pectin and BR metabolism, Cd content and the pectin methylation degree (PMD) were detected in response to K, 2,4-epibrassinolide (EBL), and brassinazole treatments of P. notoginseng and tobacco under Cd stress. Activity of the main root pectin methylesterase enzyme (PME) was promoted by 22.29% under the EBL treatment, and Cd content increased by 29.03% under Cd stress. Potassium reduced PME activity and Cd content in main root pectin by 61.03% and 50.73%, respectively, under the EBL and Cd co-treatment. Potassium inhibited the promoting effects of Cd stress on the expression of PnPME1 by 57.04%. Potassium also inhibited expression of BR synthesis genes PnDET2, PnROT3, PnCYP90A1, and PnBR6OX1 by 65.61%, 52.02%, 47.36%, and 55.16%, respectively, and reduced the accumulation of Cd. The PnPME1 was located in the CW. The activity of transgenic tobacco root PME was higher than that of the wild-type, while the PMD was significantly lower. The regulatory effects of K and EBL on tobacco root pectin metabolism were consistent with those in P. notoginseng. In conclusion, K downregulated the expression of BR synthesis genes in P. notoginseng roots under Cd stress and reduced the production of BRs, which inhibited PnPME1 expression. The reduction in PME activity increased the PMD, which reduced the accumulation of Cd.

The Intestinal Microbiota: Impacts of Antibiotics Therapy, Colonization Resistance, and Diseases.

Trillions of microbes exist in the human body, particularly the gastrointestinal tract, coevolved with the host in a mutually beneficial relationship. The main role of the intestinal microbiome is the fermentation of non-digestible substrates and increased growth of beneficial microbes that produce key antimicrobial metabolites such as short-chain fatty acids, etc., to inhibit the growth of pathogenic microbes besides other functions. Intestinal microbiota can prevent pathogen colonization through the mechanism of colonization resistance. A wide range of resistomes are present in both beneficial and pathogenic microbes. Giving antibiotic exposure to the intestinal microbiome (both beneficial and hostile) can trigger a resistome response, affecting colonization resistance. The following review provides a mechanistic overview of the intestinal microbiome and the impacts of antibiotic therapy on pathogen colonization and diseases. Further, we also discuss the epidemiology of immunocompromised patients who are at high risk for nosocomial infections, colonization and decolonization of multi-drug resistant organisms in the intestine, and the direct and indirect mechanisms that govern colonization resistance to the pathogens.