[Corythucha marmorata affects growth and quality of Artemisia argyi].

This study aims to investigate the impact of the invasive pest Corythucha marmorata on the growth and quality of Artemi-sia argyi. The signs of insect damage at the cultivation base of A. argyi in Huanggang, Hubei were observed. The pests were identified based on morphological and molecular evidence. The pest occurrence pattern and damage mechanism were investigated. Electron microscopy, gas chromatography-mass spectrometry(GC-MS), and high performance liquid chromatography(HPLC) were employed to analyze the microstructure, volatile oils, and flavonoid content of the pest-infested leaves. C. marmorata can cause destructive damage to A. argyi. Small decoloring spots appeared on the leaf surface at the initial stage of infestation. As the damage progressed, the spots spread along the leaf veins and aggregated into patches, causing yellowish leaves and even brownish yellow in the severely affected areas. The insect frequently appeared in summer because it thrives in hot dry conditions. After occurrence on the leaves, microscopic examination revealed that the front of the leaves gradually developed decoloring spots, with black oily stains formed by the black excrement attaching to the glandular hairs. The leaf flesh was also severely damaged, and the non-glandular hairs were broken, disor-ganized, and sticky. The content of neochlorogenic acid, cryptochlorogenic acid, isochlorogenic acids A and B, hispidulin, jaceosidin, and eupatilin at the early stage of infestation was significantly higher than that at the middle stage, and the content decreased at the last stage of infestation. The content of eucalyptol, borneol, terpinyl, and caryophyllin decreased in the moderately damaged leaves and increased in the severely damaged leaves. C. marmorata was discovered for the first time on A. argyi leaves in this study, and its prevention and control deserves special attention. The germplasm materials resistant to this pest can be used to breed C. marmorata-resis-tant A. argyi varieties.

[Prediction analysis of quality markers and resource evaluation of Artemisiae Argyi Folium based on chemical composition and network pharmacology].

This study is based on ultra-high-performance liquid chromatography(UPLC), gas chromatography-mass spectrometry(GC-MS), and network pharmacology methods to analyze and predict potential quality markers(Q-markers) of Artemisiae Argyi Folium. First, UPLC and GC-MS techniques were used to analyze the content of 12 non-volatile components and 8 volatile components in the leaves of 33 Artemisia argyi germplasm resources as candidate Q-markers. Subsequently, network pharmacology was employed to construct a "component-target-pathway-efficacy" network to screen out core Q-markers, and the biological activity of the markers was validated using molecular docking. Finally, cluster analysis and principal component analysis were performed on the content of Q-markers in the 33 A. argyi germplasm resources. The results showed that 18 candidate components, 60 targets, and 185 relationships were identified, which were associated with 72 pathways related to the treatment of 11 diseases and exhibited 5 other effects. Based on the combination of freedom and component specificity, six components, including eupatilin, cineole, ß-caryophyllene, dinatin, jaceosidin, and caryophyllene oxide were selected as potential Q-markers for Artemisiae Argyi Folium. According to the content of these six markers, cluster analysis divided the 33 A. argyi germplasm resources into three groups, and principal component analysis identified S14 as having the highest overall quality. This study provides a reference for exploring Q-markers of Artemisiae Argyi Folium, establishing a quality evaluation system, further studying its pharmacological mechanisms, and breeding new varieties.

Mechanisms governing the impact of nitrogen stress on the formation of secondary metabolites in Artemisia argyi leaves.

Nitrogen is a key factor in various physiological and metabolic processes in plants. Providing an adequate supply of nitrogen is essential for improving the total yield and quality of the medicinal plant Artemisia argyi (A. argyi), but the underlying mechanisms of how this nutrient alters the crop remains unclear. In this study, we conducted a series of pot experiments to investigate the agronomic traits and active components in the leaves of A. argyi plants under low and high nitrogen stress. Additionally, we used transcriptome analysis and RT-qPCR to explore the molecular pathways associated with nitrogen stress. Our results demonstrate a dramatic increase in the accumulation of phenolic acids and flavonoids in the low nitrogen (LN) stress group compared to the control (CK), with increases of 40.00% and 79.49%, respectively. Interestingly, plants in the high nitrogen (HN) stress group exhibited enhanced plant growth with larger leaves, thicker stems, and a 3% increase in volatile oil content compared to the CK. Moreover, A. argyi in the HN group displayed a 66% increase in volatile oil concentration compared to the LN group. Our combined transcriptome and q-PCR results indicate that LN stress promotes the expression of genes involved in flavonoid synthesis, while HN stress promotes the expression of genes related to terpene skeleton production and photosynthesis. Taken together, these findings suggest that different gene expression levels under LN and HN stress contribute to the photosynthesis capacity and the accumulation of active ingredients in A. argyi leaves. Our results elucidate the physiological and molecular mechanisms of nitrogen stress on A. argyi secondary metabolites and guide fertilization strategies for plant cultivation.

Effects of phosphorus stress on the growth and secondary metabolism of Artemisia argyi.

Phosphorus is essential in critical plant processes such as signaling, photosynthesis, energy metabolism, and enzyme activity during respiration. Phosphorus stress therefore has a significant impact on plant growth and metabolism. Here, we characterized the biochemical responses of Artemisia argyi Level. et Vant to low phosphorus (LP) and high phosphorus (HP) stress. Plants were treated with 0 g (LP), 1.5 g (control), or 3 g (HP) P per 10 kg of soil. The results demonstrated that CK encouraged the most plant growth, as quantified by leaf size and plant biomass. We also found that the total amounts of phenolic and flavonoid compounds (such as chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, cryptochlorogenic acid, neochlorogenic acid, hispidulin, jaceosidin, eupatilin, and casticin) were increased in the leaves of A. argyi plants exposed to LP stress compared to those raised under CK conditions. The levels of these compounds were inversely related to the amount of phosphorus added, and therefore peaked in plants treated with LP stress. Levels of terpenoids were also found to fluctuate under LP and HP stress compared to CK conditions. Furthermore, transcriptomic analyses showed up-regulation of several genes encoding key enzymes in the flavonoid and phenolic acid metabolic pathways under LP stress. There were also alterations in the expression levels of genes in the methylerythritol 4-phosphate and mevalonate pathways of terpene synthesis. This study contributes to a deeper understanding of the physiological and molecular mechanisms underlying phosphorus stress responses and their impacts on the growth and quality of the economically important species A. argyi.

Artemisia argyi allelopathy: a generalist compromises hormone balance, element absorption, and photosynthesis of receptor plants.

BACKGROUND: Allelopathy is expressed through the release of plant chemicals and is considered a natural alternative for sustainable weed management. Artemisia argyi (A. argyi) is widely distributed throughout Asia, and often dominates fields due to its strong allelopathy. However, the mechanism of A. argyi allelopathy is largely unknown and need to be elucidated at the physiological and molecular levels. RESULTS: In this study, we used electron microscopy, ionomics analysis, phytohormone profiling, and transcriptome analysis to investigate the physiological and molecular mechanisms of A. argyi allelopathy using the model plant rice (Oryza sativa) as receptor plants. A. argyi water extract (AAWE)-treated rice plants grow poorly and display root morphological anomalies and leaf yellowing. We found that AAWE significantly inhibits rice growth by destroying the root and leaf system in multiple ways, including the integrity of ultrastructure, reactive oxygen species (ROS) homeostasis, and the accumulation of soluble sugar and chlorophyll synthesis. Further detection of the hormone contents suggests that AAWE leads to indole-3-acetic acid (IAA) accumulation in roots. Moreover, ionomics analysis shows that AAWE inhibits the absorption and transportation of photosynthesis-essential mineral elements, especially Mg, Fe, and Mn. In addition, the results of transcriptome analysis revealed that AAWE affects a series of crucial primary metabolic processes comprising photosynthesis in rice plants. CONCLUSIONS: This study indicates that A. argyi realizes its strongly allelopathy through comprehensive effects on recipient plants including large-scale IAA synthesis and accumulation, ROS explosion, damaging the membrane system and organelles, and obstructing ion absorption and transport, photosynthesis and other pivotal primary metabolic processes of plants. Therefore, AAWE could potentially be developed as an environmentally friendly botanical herbicide due to its strong allelopathic effects.

Genome sequencing reveals chromosome fusion and extensive expansion of genes related to secondary metabolism in Artemisia argyi.

Artemisia argyi, as famous as Artemisia annua, is a medicinal plant with huge economic value in the genus of Artemisia and has been widely used in the world for about 3000 years. However, a lack of the reference genome severely hinders the understanding of genetic basis for the active ingredient synthesis of A. argyi. Here, we firstly report a complex chromosome-level genome assembly of A. argyi with a large size of 8.03 Gb, with features of high heterozygosity (2.36%), high repetitive sequences (73.59%) and a huge number of protein-coding genes (279 294 in total). The assembly reveals at least three rounds of whole-genome duplication (WGD) events, including a recent WGD event in the A. argyi genome, and a recent burst of transposable element, which may contribute to its large genome size. The genomic data and karyotype analyses confirmed that A. argyi is an allotetraploid with 34 chromosomes. Intragenome synteny analysis revealed that chromosomes fusion event occurred in the A. argyi genome, which elucidates the changes in basic chromosome numbers in Artemisia genus. Significant expansion of genes related to photosynthesis, DNA replication, stress responses and secondary metabolism were identified in A. argyi, explaining the extensive environmental adaptability and rapid growth characteristics. In addition, we analysed genes involved in the biosynthesis pathways of flavonoids and terpenoids, and found that extensive gene amplification and tandem duplication contributed to the high contents of metabolites in A. argyi. Overall, the reference genome assembly provides scientific support for evolutionary biology, functional genomics and breeding in A. argyi and other Artemisia species.

[Content of mineral elements in different Artemisia argyi germplasms and their relationship with quality properties].

To clarify the content characteristics of mineral elements in different Artemisia argyi germplasm resources and their relationship with the quality properties of Artemisiae Argyi Folium, this study measured the content of 10 mineral elements including nitrogen(N), phosphorus(P), potassium(K), calcium(Ca), magnesium(Mg), aluminum(Al), manganese(Mn), iron(Fe), copper(Cu), and zinc(Zn) in 100 Artemisia argyi germplasm samples. Besides, their relationship with the quality properties of Artemisiae Argyi Folium was explored by correlation analysis, path analysis, and cluster analysis. The results demonstrated that the variation coefficient of the 10 mineral elements in Artemisiae Argyi Folium ranged from 12.23% to 64.38%, and the genetic diversity index from 0.97 to 3.09. The genetic diversities of N, P, and Zn were obvious. As revealed by the correlation analysis, N, P, and K showed strong positive correlations with each other. Except that Mg and Al were negatively correlated, Ca, Mg, Al, Mn, Fe, Cu, and Zn were positively correlated. The correlation analysis of mineral elements with the quality properties of Artemisiae Argyi Folium proved the significant correlations of 17 pairs of characters. According to the path analysis, P, K, Ca, and Mn greatly affected the yield of Artemisiae Argyi Folium, P, K, and Mg the output rate of moxa, N, P, and K the content of total volatile oil, P and K the content of eucalyptol, and P, K, and Ca the content of eupatilin. The 100 germplasm samples were clustered into three groups. Specifically, in cluster Ⅰ, the enrichment capacity of P, K, and Mg elements was strong, and the comprehensive properties of mineral elements were better, implying good development potential. Ca, Mn, Fe, and Zn elements in cluster Ⅱ and N and Al in cluster Ⅲ displayed strong enrichment capacities. This study has provided new ideas for resource evaluation and variety breeding of A. argyi and also reference for fertilizer application.

[Analysis and evaluation of volatile oil content in leaves of different Artemisia argyi germplasm resources].

Volatile oil is the main effective component and an important quality indicator of Artemisia argyi leaves. In this study, 100 germplasm resources of A. argyi were collected from all the related habitats in China. The total volatile oils in A. argyi leaves were extracted by steam distillation and the content was determined by GC-MS. The result demonstrated that the content of total volatile oils was in the range of 0.53%-2.55%, with the average of 1.43%. A total of 39 chemical constituents were identified from the volatile oils, including 13 shared by the 100 germplasm resources. Clustering analysis of the 39 constituents showed that the 100 A. argyi samples were categorized into groups Ⅰ(9), Ⅱ(2), Ⅲ(66) and Ⅳ(23), and group Ⅲ had the most volatile medicinal components, with the highest content. Five principal components(PCs) were extracted from 13 shared constituents, which explained 73.454% of the total variance. PC1, PC2, and PC3 mainly reflected the pharmacological activity of volatile oils and the rest two the aroma information. The volatile oils identified in this study lay a foundation for variety breeding of and rational utilization of volatile oils in A. argyi leaves.

[Diversity of Artemisia argyi germplasm resources based on agronomic and leaf phenotypic traits].

In this study, in order to evaluate the phenotypic diversity of Artemisia argyi germplasm resources and improve its efficiency of cultivation and breeding, 100 accessions of A. argyi germplasm resources from 58 regions in China were collected, 20 agronomic traits and leaf phenotypic traits were observed and described. The data were used for phenotypic diversity analysis, correlation analysis, principal component analysis and cluster analysis. The result showed that the genetic diversity index of 20 traits ranged from 0.82 to 4.37, among which the largest was the base depth and the smallest was the leaf width; the coefficient of variation of the 12 quantitative traits ranged from 10.55% to 41.47%. the highest coefficient of variation was the height of dead leaves, and the smallest was the content of chlorophyll, except for the angle of branches, all the quantitative characters tended to be normal distribution. The correlation analysis showed that 28 pairs of traits had significant correlation(P<0.01), and 13 pairs had significant correlation(P<0.05). According to principal component analysis, 20 traits were simplified into 9 principal components, and the cumulative contribution rate was 73.414%, nine traits including plant height, dead leaves heigh, stem diameter, symmetry of leave base, stipule, leaf tip shape, depth of the first pair of lobes, depth of the second pair of lobes and leaf yield were selected as key indexes for evaluating agronomic traits and leaf phenotypic traits of A.argyi germplasm resources. With cluster analysis, 100 accessions of A.argyi were classified into 3 groups, the groupⅠincluded the dwarf plants with thick stem and large leaf, the groupⅡincluded high plants with wide leaf and high yield, the group Ⅲ included dwarf plants with thin stem and flat bottom shape of leaf, which could provide the basis for cultivation identification and variety breeding of A.argyi germplasm resources.

[Effect of mitochondrial DNA deletion on growth and invasiveness of human lymphoma Namalwa cells].

OBJECTIVE: To explore the effect of mitochondrial DNA (mtDNA) deletion on the growth and invasiveness of human lymphoma Namalwa cells. METHODS: ρ(0)-Namalwa cells with mtDNA deletion were generated by treating Namalwa cells with ethidium bromide and confirmed by selective ρ(0) test medium analysis, PCR and Western blotting. The growth of ρ(0)-Namalwa cells was evaluated by MTT assay and cell cycle analysis, and the cell migration and invasiveness were assessed with Transwell assay. Reactive oxygen species (ROS) production and cytosolic Ca(2+) were detected by flow cytometry. RESULTS: ρ(0)-Namalwa cells could grow and divide normally in selective medium supplemented with uridine and pyruvate but not in nonselective medium. PCR did not yield the products of mtDNA, nor was COXII expression detected in ρ(0)-Namalwa cells. ρ(0)-Namalwa cells showed an obvious attenuation of cell proliferation and migration abilities with significantly lowered ROS production and cytosolic Ca(2+). CONCLUSION: The suppressed growth and migration of ρ(0)-Namalwa cells may be the result of decreased ROS production and cytosolic Ca(2+).

[Grape seed extract inhibit proliferation of breast cancer cell MCF-7 and decrease the gene expression of survivin].

OBJECTIVE: To observe the effect of grape seed extract (GSE) on breast cancer cell MCF-7 about the of proliferation and the gene expression of survivin, and to investigate the molecular biological mechanism of inhibition by GSE. METHOD: MTT was used to measure the role of proliferated inhibition of GSE at the dosage of 40, 80, 120, 160, 200 mg x L(-1) with different time. To calculate the IC50 of GSE and to select the suitable concentration and treatment time. The change of cell cycle was detected by flow cytometry. mRNA expression of Survivin was observed by RT-PCR. Luciferase kit was used to observe the change of core promoter of survivin which was inserted in the flourescence report vector. And further to analyse the bind side of transcription factor on the sequence of core promoter of survivin was further analysed by using the microsoft of bioinformatics. RESULT: GSE could inhibit the proliferation of breast cancer cell MCF-7 with time and dosage-dependent (P < 0.05). GSE could arrest the cell cycle in S periods (P < 0.05) and also inhibit the mRNA expression of survivin effectively (P < 0.01); GSE could down-regulate the activity of core promoter of survivin significantly (P < 0.01). CONCLUSION: GSE can inhibit the proliferation of breast cancer cell MCF-7 through arresting the cell cycle in S periods. The mechanism may be that GSE regulate the activity of transcription factor which are related to the activity of core promoter of survivin and decrease the gene expression of survivin.