Revealing the hidden burden for lake management: the sediment phosphorus storage pools in Eastern Plain Lake Zone, China.

As one of the essential components in ecosystems, lakes play a major role in the global phosphorus (P) cycle. It is helpful for further understanding of the inside lake P geochemical cycle to research P pollution and storage in lakes, which is of positive significance for lake eutrophication restoration. In this study, we investigated the total phosphorus concentrations (TPC) of water and sediments from 37 lakes in the Eastern Plain Lake Zone (EPL) of China, evaluated the P pollution degree of lakes, and estimated P storage in lake sediments with quantitative data of lake area and number. The results indicate that the total phosphorus concentrations of water (TPCW) and total phosphorus concentrations of the surface sediments (0-1 cm, TPCSS) in EPL were high, the mean values were 0.11 mg·L-1 and 869.85 mg·kg-1 respectively, with obvious differences between urban and rural areas, as well as between different river basins. Over half (56.76% and 70.27% respectively) of the lakes reached severe pollution levels in water and surface sediments. There were 16224 lakes (> 0.01 km2) with a total area of 21662.37 km2 in the EPL, and the P storage in the lake sediments (0-30 cm) was about 4.87 ± 2.08 Tg (1 Tg = 1 × 1012 g), accounting for about 2.74% of the basin soil. TPCW and TPCSS of lakes in the EPL were significantly positively correlated, may suggest a close nutrient cycling relationship between the lake water and the sediment. During periods of high winds and waves, the stored P in the top sediments in the EPL may continue to participate in the internal P geochemical cycle and migrate to the overlying water, posing a potential pollution hazard. Therefore, it is crucial to take into account the sediment P pools when formulating effective lake phosphorus management strategies.

Phylogenomic analysis, cryptic species discovery, and DNA barcoding of the genus Cibotium in China based on plastome data.

Germplasm resources are the source of herbal medicine production. The cultivation of superior germplasm resources helps to resolve the conflict between long-term population persistence and growing market demand by consistently producing materials with high quality. The fern species Cibotium barometz is the original plant of cibotii rhizoma ("Gouji"), a traditional Chinese medicine used in the therapy of pain, weakness, and numbness in the lower extremities. Long-history medicinal use has caused serious wild population decline in China. Without sufficient understanding of the species and lineage diversity of Cibotium, it is difficult to propose a targeted conservation scheme at present, let alone select high-quality germplasm resources. In order to fill such a knowledge gap, this study sampled C. barometz and relative species throughout their distribution in China, performed genome skimming to obtain plastome data, and conducted phylogenomic analyses. We constructed a well-supported plastome phylogeny of Chinese Cibotium, which showed that three species with significant genetic differences are distributed in China, namely C. barometz, C. cumingii, and C. sino-burmaense sp. nov., a cryptic species endemic to NW Yunnan and adjacent regions of NE Myanmar. Moreover, our results revealed two differentiated lineages of C. barometz distributed on the east and west sides of a classic phylogeographic boundary that was probably shaped by monsoons and landforms. We also evaluated the resolution of nine traditional barcode loci and designed five new DNA barcodes based on the plastome sequence that can distinguish all these species and lineages of Chinese Cibotium accurately. These novel findings on a genetic basis will guide conservation planners and medicinal plant breeders to build systematic conservation plans and exploit the germplasm resources of Cibotium in China.

Sociodemographic and Health Correlates of Multiple Health Behavior Adherence among Cancer Survivors: A Latent Class Analysis.

The study aimed to (a) assess current levels of adherence to the National Comprehensive Cancer Network's multiple health behavior guidelines and (b) identify characteristics of cancer survivors associated with different adherence levels. Cancer survivors (N = 661) were identified through the state registry and completed questionnaires. Latent class analysis (LCA) was used to identify patterns of adherence. Associations between predictors with the latent classes were reported as risk ratios. LCA identified three classes: lower- (39.6%), moderate- (52.0%), and high-risk lifestyle (8.3%). Participants in the lower-risk lifestyle class had the highest probability of meeting most of the multiple health behavior guidelines compared to participants in the high-risk lifestyle class. Characteristics associated with membership in the moderate-risk lifestyle class included self-identifying as a race other than Asian/Asian American, being never married, having some college education, and having been diagnosed with later stage colorectal or lung cancer. Those in the high-risk lifestyle class were more likely to be male, never married, have a high school diploma or less, diagnosed with colorectal or lung cancer, and diagnosed with pulmonary comorbidities. Study findings can be used to inform development of future interventions to promote multiple health behavior adherence among higher risk cancer survivors.

Folate Intake and Ovarian Cancer Risk among Women with Endometriosis: A Case-Control Study from the Ovarian Cancer Association Consortium.

BACKGROUND: Although folate intake has not been associated with an increased risk of ovarian cancer overall, studies of other cancer types have suggested that high folate intake may promote carcinogenesis in precancerous lesions. Women with endometriosis (a potential precancerous lesion) have an increased risk of developing ovarian cancer; however, whether high folate intake increases risk in this group is unknown. METHODS: We conducted a pooled analysis of six case-control studies from the Ovarian Cancer Association Consortium to investigate the association between folate intake and risk of ovarian cancer among women with and without self-reported endometriosis. We included 570 cases/558 controls with and 5,171/7,559 without endometriosis. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals for the association between folate intake (dietary, supplemental, and total) and ovarian cancer risk. Finally, we used Mendelian randomization (MR) to evaluate our results using genetic markers as a proxy for folate status. RESULTS: Higher dietary folate intake was associated with an increased risk of ovarian cancer for women with endometriosis [OR, 1.37 (1.01-1.86)] but not for women without endometriosis. There was no association between supplemental folate intake and ovarian cancer risk for women with or without endometriosis. A similar pattern was seen using MR. CONCLUSIONS: High dietary folate intake may be associated with an increased risk of ovarian cancer among women with endometriosis. IMPACT: Women with endometriosis with high folate diets may be at increased risk of ovarian cancer. Further research is needed on the potential cancer-promoting effects of folate in this group.

Spirituality and financial toxicity among Hispanic breast cancer survivors in New Jersey.

OBJECTIVE: Cancer survivors often incur significant out-of-pocket costs; this can result in financial toxicity, defined as the adverse financial impact of cancer due to direct or indirect costs related to the disease. There has been little research on whether spirituality is associated with the experience of financial toxicity. In this study, we tested the hypothesis that spirituality would be inversely associated with financial toxicity. METHODS: We evaluated these associations in a cross-sectional study of Hispanic breast cancer survivors (n = 102) identified through the New Jersey State Cancer Registry. Participants completed the FACIT-Sp-12, which has two spirituality subscales (meaning/peace; faith). Financial toxicity was assessed using the 11-item COST measure; lower scores suggest worse toxicity. In multivariable linear regression analyses, we examined the associations between spirituality scores and financial toxicity, adjusting for age, race, education, household income, and insurance status. RESULTS: The spirituality total score (ß = 0.49, 95% confidence interval (CI): 0.17, 0.8), meaning/peace subscale score (ß = 0.71, 95% CI: 0.12, 1.31), and faith (ß = 0.71, 95% CI: 0.2, 1.21) subscale score were all inversely associated with financial toxicity. CONCLUSIONS: Spirituality may be an important factor in ameliorating the detrimental effects of financial toxicity among Hispanic breast cancer survivors and should be considered in interventions for financial toxicity in this population.

Integrative transcriptional characterization of cell cycle checkpoint genes promotes clinical management and precision medicine in bladder carcinoma.

Background: The aberrant regulation of cell cycle is significantly correlated with cancer carcinogenesis and progression, in which cell cycle checkpoints control phase transitions, cell cycle entry, progression, and exit. However, the integrative role of cell cycle checkpoint-related genes (CRGs) in bladder carcinoma (BC) remains unknown. Methods: The transcriptomic data and clinical features of BC patients were downloaded from The Cancer Genome Atlas (TCGA), used to identify CRGs correlated with overall survival (OS) by univariate Cox regression analysis. Then, the multivariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses further developed a prognostic CRG signature, which was validated in three external datasets retrieved from Gene Expression Omnibus (GEO). The receiver operating characteristic curve (ROC) analysis was conducted for evaluating the performance of the CRG signature in prognosis prediction. RNA sequencing (RNA-Seq) was performed to explore the expression difference in the identified CRGs between tumor and normal tissue samples from 11 BC patients in the local cohort. Ultimately, genomic profiles and tumor microenvironment (TME), and the Genomics of Drug Sensitivity in Cancer (GDSC) were investigated to guide precision treatment for BC patients with different CRG features. Results: The novel constructed 23-CRG prognostic signature could stratify BC patients into high-risk and low-risk groups with significantly different outcomes (median OS: 13.64 vs. 104.65 months). Notably, 19 CRGs were the first to be identified as being associated with BC progression. In three additional validation datasets (GSE13507, GSE31684, and GSE32548), higher CRG scores all indicated inferior survival, demonstrating the robust ability of the CRG signature in prognosis prediction. Moreover, the CRG signature as an independent prognostic factor had a robust and stable risk stratification for BC patients with different histological or clinical features. Then, a CRG signature-based nomogram with a better performance in prognostic prediction [concordance index (C-index): 0.76] was established. Functional enrichment analysis revealed that collagen-containing extracellular matrix (ECM), and ECM-related and MAPK signaling pathways were significantly associated with the signature. Further analysis showed that low-risk patients were characterized by particularly distinctive prevalence of FGFR3 (17.03% vs. 6.67%, p < 0.01) and POLE alterations (7.97% vs. 2.50%, p < 0.05), and enrichment of immune infiltrated cells (including CD8+ T cells, CD4+ naïve T cells, follicular helper T cells, Tregs, and myeloid dendritic cells). RNA-seq data in our local cohort supported the findings in the differentially expressed genes (DEGs) between tumor and normal tissue samples, and the difference in TME between high-risk and low-risk groups. Additionally, CRG signature score plus FGFR3 status divided BC patients into four molecular subtypes, with distinct prognosis, TME, and transcriptomic profiling of immune checkpoint genes. Of note, CRG signature score plus FGFR3 status could successfully distinguish BC patients who have a higher possibility of response to immunotherapy or chemotherapy drugs. Conclusions: The CRG signature is a potent prognostic model for BC patients, and in combination with FGFR3 alterations, it had more practical capacity in the prediction of chemotherapy and immunotherapy response, helping guide clinical decision-making.

Biomarkers for Predicting Abiraterone Treatment Outcome and Selecting Alternative Therapies in Castration-Resistant Prostate Cancer.

Approximately one-third of patients with metastatic castration-resistant prostate cancer (CRPC) exhibited primary abiraterone resistance. To identify alternative treatment for abiraterone nonresponders, we performed drug discovery analyses using the L1000 database using differentially expressed genes identified in tumor biopsies and patient-derived xenograft (PDX) tumors between abiraterone responders and nonresponders enrolled in PROMOTE trial. This approach identified 3 drugs, including topoisomerase II (TOP2) inhibitor mitoxantrone, CDK4/6 inhibitor palbociclib, and pan-CDK inhibitor PHA-793887. These drugs significantly suppressed the growth of abiraterone-resistant cell lines and PDX models. Moreover, we identified 11 genes targeted by all 3 drugs that were associated with worse outcomes in both the PROMOTE and Stand Up To Cancer cohorts. This 11-gene panel might also function as biomarkers to select the 3 alternative therapies for this subgroup of patients with CRPC, warranting further clinical investigation.

The complete chloroplast genome of Tetrastigma planicaule, one important folk medicinal plant in China.

We announce here the first complete chloroplast genome sequence of Tetrastigma planicaule, one important Chinese folk medicinal plant. This complete chloroplast genome is 160,323 bp in length. In total, 131 genes were identified, including 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The results of phylogenetic analysis indicated that Tetrastigma is a separate genus and is closely related to Vitis.

Intake of vitamin D and calcium, sun exposure, and risk of breast cancer subtypes among black women.

BACKGROUND: The randomized placebo-controlled Vitamin D and Omega-3 Trial suggested a possible benefit of vitamin D on cancer incidence among black individuals. However, data are limited regarding the impact of vitamin D on breast cancer subtypes among African-American/black women, who tend to develop more aggressive forms of breast cancer. OBJECTIVES: We hypothesize that more vitamin D exposure (through diet, supplements, and sunlight) and higher intake of calcium are associated with decreased risk of estrogen receptor (ER)+ and ER- breast cancer, and of triple-negative breast cancer (TNBC) among black women. METHODS: This study was conducted among 1724 black cases and 1233 controls in the Women's Circle of Health Study (WCHS) and WCHS2. Polytomous logistic regressions were used to estimate ORs and 95% CIs of ER+ and ER- breast cancer; logistic regressions were used for TNBC. The ORs from each study were pooled using an inverse-variance-weighted random-effects model. RESULTS: Dietary vitamin D and calcium intake were not associated with risk of breast cancer subtypes in the pooled analysis. For supplemental vitamin D, we observed possible inverse associations between intake of ≤800 IU/d (compared with nonuse) and risk of several subtypes, with effects that appeared strongest for TNBC (OR: 0.58; 95% CI: 0.35, 0.94); no association was found for >800 IU/d. More daylight hours spent outdoors in a year was associated with lower risk of ER+, ER-, and TNBC (e.g., highest compared with lowest quartile: TNBC OR: 0.53; 95% CI: 0.31, 0.91; P-trend = 0.02). CONCLUSIONS: Moderate supplemental vitamin D intake was associated with decreased risk of TNBC, and increased sun exposure was associated with reduced risk of ER+, ER-, and TNBC among black women.

Therapeutic observation of cranial suture acupuncture in treating depression / 针灸推拿医学（英文版）

Objective:To observe the clinical efficacy and safety of cranial suture acupuncture plus paroxetine in treating depression,and to discuss the action mechanism of this acupuncture method.Methods:One hundred depression patients were allocated to an observation group and a control group according to the random number table,with 50 cases in each group.The control group was intervened by oral administration of paroxetine tablets,20 mg each time,once a day for successive 6 weeks;the observation group was additionally given cranial suture acupuncture,once a day for 6 weeks.They were scored by Hamilton depression scale-17 (HAMD-17) before the treatment and respectively after 1-week,2-week,4-week and 6-week treatment.The clinical efficacy and safety were also observed.Results:After 6-week treatment,the total effective rate was 94.0％ in the observation group versus 78.0％ in the control group,and the between-group difference was statistically significant (P＜0.01).The HAMD-17 scores respectively after 1-week,2-week,4-week and 6-week treatment were significantly lower than the score before the treatment in the observation group (all P＜0.05);the HAMD-17 scores respectively after 2-week,4-week and 6-week treatment were significantly different from the score before the treatment in the control group (all P＜0.05).There were significant differences in the HAMD-17 score between the two groups respectively after 4-week and 6-week treatment (both P＜0.05).Conclusion:Cranial suture acupuncture plus paroxetine can ease the symptoms of depression,with faster onset and more significant therapeutic efficacy compared with paroxetine alone.

Intake of niacin, folate, vitamin B-6, and vitamin B-12 through young adulthood and cognitive function in midlife: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

Background: Epidemiologic evidence regarding niacin, folate, vitamin B-6, and vitamin B-12 intake in relation to cognitive function is limited, especially in midlife.Objective: We hypothesize that higher intake of these B vitamins in young adulthood is associated with better cognition later in life.Design: This study comprised a community-based multicenter cohort of black and white men and women aged 18-30 y in 1985-1986 (year 0, i.e., baseline) from the Coronary Artery Risk Development in Young Adults (CARDIA) study (n = 3136). We examined participants' CARDIA diet history at years 0, 7, and 20 to assess nutrient intake, including dietary and supplemental B vitamins. We measured cognitive function at year 25 (mean ± SD age: 50 ± 4 y) through the use of the Rey Auditory Verbal Learning Test (RAVLT) for verbal memory, the Digit Symbol Substitution Test (DSST) for psychomotor speed, and a modified Stroop interference test for executive function. Higher RAVLT and DSST scores and a lower Stroop score indicated better cognitive function. We used multivariable-adjusted linear regressions to estimate mean differences in cognitive scores and 95% CIs.Results: Comparing the highest quintile with the lowest (quintile 5 compared with quintile 1), cumulative total intake of niacin was significantly associated with 3.92 more digits on the DSST (95% CI: 2.28, 5.55; P-trend < 0.01) and 1.89 points lower interference score on the Stroop test (95% CI: -3.10, -0.68; P-trend = 0.05). Total folate was associated with 2.56 more digits on the DSST (95% CI: 0.82, 4.31; P-trend = 0.01). We also found that higher intakes of vitamin B-6 (quartile 5 compared with quartile 1: 2.62; 95% CI: 0.97, 4.28; P-trend = 0.02) and vitamin B-12 (quartile 5 compared with quartile 1: 2.08; 95% CI: 0.52, 3.65; P-trend = 0.02) resulted in better psychomotor speed measured by DSST scores.Conclusion: Higher intake of B vitamins throughout young adulthood was associated with better cognitive function in midlife.

Supplemental Selenium May Decrease Ovarian Cancer Risk in African-American Women.

Background: To our knowledge, no previous study has evaluated the associations of antioxidant intake with the risk of ovarian cancer in African-American women, who are known to have high mortality from the disease.Objective: We sought to evaluate these associations among 406 ovarian cancer cases and 632 age- and site-matched controls of African-American descent recruited from AACES (African American Cancer Epidemiology Study), a population-based, case-control study in 11 geographical areas within the United States.Methods: Multivariable logistic regression models were used to estimate ORs and 95% CIs adjusted for a wide range of potentially confounding factors, including age, region, education, parity, oral contraceptive use, menopause, tubal ligation, family history, body mass index (BMI), smoking status, total energy, and physical activity.Results: Women with the highest intakes of supplemental selenium (>20 µg/d) had an ∼30% lower risk of ovarian cancer than those with no supplemental intake (OR: 0.67; 95% CI: 0.46, 0.97; P-trend = 0.035). This inverse association was stronger in current smokers (OR: 0.13; 95% CI: 0.04, 0.46; P-trend = 0.001). There was no association with dietary selenium. The associations with carotenoid intakes were weak and nonsignificant (P = 0.07-0.60). We observed no association with dietary or supplemental intake of vitamin C or vitamin E. There were no appreciable differences in results between serous and nonserous tumors.Conclusions: These findings provide the first insights, to our knowledge, into the potential association between antioxidants and ovarian cancer in African-American women, indicating potential inverse associations with supplemental selenium.

[Effect of pushing manipulation on Qiaogong acupoint on hemodynamics in cynomolgus monkeys with mild carotid atherosclerotic plaques].

OBJECTIVE: To explore the hemodynamic changes in cynomolgus monkeys with mild carotid atherosclerotic (CAS) plaques after therapy with pushing manipulation on Qiaogong acupoint (MPQ). METHODS: Nine cynomolgus monkeys were equally randomized into MPQ group, mild CAS model group and blank control group. Mild CAS models were established in the monkeys in MPQ and model groups, and the monkeys in MPQ group received treatment with MPQ intervention after the modeling. The conditions of the carotid artery and the hemodynamic changes in the 3 groups were evaluated after the treatment. RESULTS: Formation of CAS plaques was detected in monkeys in both MPQ and model groups. The vascular cross?sectional area, plaque cross?sectional area and stenosis rate of the plaques in the two groups all differed significantly from those in the blank control group (P<0.05), but these parameters were similar between MPQ group and the model group (P>0.05). Compared with those in the blank control group, the hemodynamic parameters showed significant changes in MPQ and the model groups (P<0.05) but remained similar between the latter two groups (P>0.05). CONCLUSION: CAS plaques can cause changes in hemodynamic parameters. Short?term therapy with MPQ does not affect the stability of the plaques or cause adverse effects on hemodynamics in cynomolgus monkeys with mild CAS plaques.

Flavoniods from aerial parts of Astragalus hoantchy.

Four new flavonoids, astragaisoflavans A-D (1-4), along with thirteen known ones (5-17) were isolated from the aerial parts of Astragalus hoantchy. Their structures were established by the extensive spectroscopic analyses including one- and two-dimensional NMR, HRESIMS, IR, and UV results. The absolute configurations of 1-4 were deduced based on circular dichroism. Compounds 1-3 all possessed a rare modified A-ring and compound 4 was a dimeric isoflavan. Compound 5 was first identified from genus Astragalus and 6-17 were found from A. hoantchy for the first time. Compound 1 and 4 were evaluated for their antifungal activity against Alternaria solani (a phytopathogenic fungus), with the result that 1 failed to exhibit significant antifungal activity at the testing concentration of 100µg/mL and the IC50 value of 4 was 173.3µg/mL.

Allelochemicals from the Rhizosphere Soil of Cultivated Astragalus hoantchy.

Astragalus hoantchy, a widely cultivated medicinal plant species in traditional Chinese and Mongolian medicine, has been often hampered by replant failure during cultivation, like many other herbs of the genus Astragalus. Root aqueous extracts of Astragalus herbs were reported to exhibit allelopathic activity against other plants and autotoxic activity on their own seedlings, but the allelochemicals released by Astragalus plants have not been specified so far. Ten compounds were isolated from the rhizosphere soil extract of cultivated A. hoantchy and elucidated by spectroscopic analysis. Compounds 1-6 observably showed allelopathic activity against Lactuca sativa seedlings and autotoxic activity against A. hoantchy seedlings. The isolated compounds were further confirmed and quantified by high-performance liquid chromatography (HPLC) in the rhizosphere soil, with a total concentration of 9.78 µg/g (dry weight). These results specify and verify the allelochemicals released by cultivated A. hoantchy into the soil environment, which may provide new insights into the allelopathic mechanisms of this medicinal plant and probably assist in clarifying the replant problems of Astragalus plants.

Seven-day triple therapy is a better choice for Helicobacter pylori eradication in regions with low antibiotic resistance.

AIM: To investigate whether 7-d triple therapies are still valid in populations with low levels of resistance. METHODS: A total of 1106 Helicobacter pylori (H. pylori)-positive patients were divided into three groups, each of which received one type of 7-d triple therapy. Therapeutic outcomes of the patients were assessed by the (13)C-urea breath test at 8 wk after treatment. The susceptibility of H. pylori to antibiotics was determined by an agar-dilution method. Data analysis was performed by χ(2) tests. RESULTS: The eradication rates in groups A, B and C were 90.71% (332/366), 90.46% (313/346) and 90.87% (189/208), respectively (P = 0.986). The resistance rates were 8.91% for clarithromycin, 14.78% for levofloxacin and 0% for amoxicillin. The eradication rate was significantly different between clarithromycin- and levofloxacin-resistant patients (P < 0.05) in group A. Patients whose treatment failed in group A also had a higher clarithromycin resistance rate than did successive patients (P = 0.034). However, levofloxacin resistance had no obvious influence on the eradication rate. Furthermore, three main antibiotics (clarithromycin, levofloxacin and amoxicillin) had lower DID (defined daily dose per 1000 inhabitants per day) in this city. CONCLUSION: Clarithromycin resistance is the main reason for the failure of 7-d triple therapy. In populations with low levels of resistance, a 7-d triple therapy is a viable choice. The choice of therapy should not be influenced by conditions in high antibiotic resistance regions.

Isolation, Identification, and Autotoxicity Effect of Allelochemicals from Rhizosphere Soils of Flue-Cured Tobacco.

Autotoxicity, defined as a deleterious allelopathic effect among individuals of the same plant species, is considered as one of the factors that contributes to replant failure. Tobacco, as an important cultured and economic crop over the world, has been often hampered by replant failure. In view of the seriousness of this problem, the allelochemicals of flue-cured tobacco and their allelopathic effects were investigated. The extracts of rhizosphere soil exhibited phytotoxic activities against Lactuca sativa and autotoxic activities against tobacco itself. Bioassay-guided fractionation of the extract led to the isolation of six compounds, the structures of which were elucidated by spectroscopic analysis. Among them, ß-cembrenediol (1), di-n-hexyl phthalate (2), and bis(2-propylheptyl) phthalate (3) showed observably phytotoxic activities against L. sativa seedlings and autotoxic activities on tobacco. The allelochemicals were then verified in the root zone soils of flue-cured tobacco by high-performance liquid chromatography (HPLC). These results provide new insights into the allelopathic mechanisms involved in the replant failure of flue-cured tobacco.

Phylogenic diversity and tissue specificity of fungal endophytes associated with the pharmaceutical plant, Stellera chamaejasme L. revealed by a cultivation-independent approach.

The fungal endophytes associated with medicinal plants have been demonstrated as a reservoir with novel natural products useful in medicine and agriculture. It is desirable to explore the species composition, diversity and tissue specificity of endophytic fungi that inhabit in different tissues of medicinal plants. In this study, a culture-independent survey of fungal diversity in the rhizosphere, leaves, stems and roots of a toxic medicinal plant, Stellera chamaejasme L., was conducted by sequence analysis of clone libraries of the partial internal transcribed spacer region. Altogether, 145 fungal OTUs (operational taxonomic units), represented by 464 sequences, were found in four samples, of these 109 OTUs (75.2 %) belonging to Ascomycota, 20 (13.8 %) to Basidiomycota, 14 (9.7 %) to Zygomycota, 1 (0.7 %) to Chytridiomycota, and 1 (0.7 %) to Glomeromycota. The richness and diversity of fungal communities were strongly influenced by plant tissue environments, and the roots are associated with a surprisingly rich endophyte community. The endophyte assemblages associated with S. chamaejasme were strongly shaped by plant tissue environments, and exhibited a certain degree of tissue specificity. Our results suggested that a wide variety of fungal assemblages inhabit in S. chamaejasme, and plant tissue environments conspicuously influence endophyte community structure.

Isolation and characterization of bacteria from the rhizosphere and bulk soil of Stellera chamaejasme L.

This study is the first to describe the composition and characteristics of culturable bacterial isolates from the rhizosphere and bulk soil of the medicinal plant Stellera chamaejasme L. at different growth stages. Using a cultivation-dependent approach, a total of 148 isolates showing different phenotypic properties were obtained from the rhizosphere and bulk soil. Firmicutes and Actinobacteria were the major bacterial groups in both the rhizosphere and bulk soil at all 4 growth stages of S. chamaejasme. The diversity of the bacterial community in the rhizosphere was higher than that in bulk soil in flowering and fruiting stages. The abundance of bacterial communities in the rhizosphere changed with the growth stages and had a major shift at the fruiting stage. Dynamic changes of bacterial abundance and many bacterial groups in the rhizosphere were similar to those in bulk soil. Furthermore, most bacterial isolates exhibited single or multiple biochemical activities associated with S. chamaejasme growth, which revealed that bacteria with multiple physiological functions were abundant and widespread in the rhizosphere and bulk soil. These results are essential (i) for understanding the ecological roles of bacteria in the rhizosphere and bulk soil and (ii) as a foundation for further evaluating their efficacy as effective S. chamaejasme growth-promoting rhizobacteria.

Mechanism of artemisinin phytotoxicity action: induction of reactive oxygen species and cell death in lettuce seedlings.

Artemisinin has been recognized as an allelochemical that inhibits growth of several plant species. However, its mode of action is not well clarified. In this study, the mechanism of artemisinin phytotoxicity on lettuce seedlings was investigated. Root and shoot elongation of lettuce seedlings were inhibited by artemisinin in a concentration-dependent manner. The compound effectively arrested cell division and caused loss of cell viability in root tips of lettuce. Overproduction of reactive oxygen species (ROS) was induced by artemisinin. Lipid peroxidation, proline overproduction and reduction of chlorophyll content in lettuce seedlings were found after treatments. These results suggested that artemisinin could induce ROS overproduction, which caused membrane lipids peroxidation and cell death, and impacted mitosis and physiological processes, resulting in growth inhibition of receptor plants.