Phenolic Acid Derivatives from Ficus esquiroliana Levl. and Their Anti-Inflammatory Effects.

One new mesomer, ficusnaph A (1), two new phenolic acid derivatives, ficusnaphs B and C (2 and 3) together with three known biogenetically related polysubstituted naphthalene derivatives (4-6) were isolated from the stems of Ficus esquiroliana Levl. The structures of these compounds were elucidated using comprehensive spectroscopic methods. Compounds 1-6 were evaluated the inhibitory activities against the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in mouse macrophage RAW264.7 cells in vitro. Compounds 1 and 2 showed significant inhibitory activity with the IC50 value of 3.12±0.14 and 7.66±0.18 µM, respectively.

Fluoride absorption, transportation and tolerance mechanism in Camellia sinensis, and its bioavailability and health risk assessment: a systematic review.

Tea is the one of the most popular non-alcoholic caffeinated beverages in the world. Tea is produced from the tea plant (Camellia sinensis (L.) O. Kuntze), which is known to accumulate fluoride. This article systematically analyzes the literature concerning fluoride absorption, transportation and fluoride tolerance mechanisms in tea plants. Fluoride bioavailability and exposure levels in tea infusions are also reviewed. The circulation of fluoride within the tea plantation ecosystems is in a positive equilibrium, with greater amounts of fluoride introduced to tea orchards than removed. Water extractable fluoride and magnesium chloride (MgCl2 ) extractable fluoride in plantation soil are the main sources of absorption by tea plant root via active trans-membrane transport and anion channels. Most fluoride is readily transported through the xylem as F- /F-Al complexes to leaf cell walls and vacuole. The findings indicate that tea plants employ cell wall accumulation, vacuole compartmentalization, and F-Al complexes to co-detoxify fluoride and aluminum, a possible tolerance mechanism through which tea tolerates higher levels of fluoride than most plants. Furthermore, dietary and endogenous factors influence fluoride bioavailability and should be considered when exposure levels of fluoride in commercially available dried tea leaves are interpreted. The relevant current challenges and future perspectives are also discussed. © 2020 Society of Chemical Industry.

Risk factors affecting prognosis in metachronous liver metastases from WHO classification G1 and G2 gastroenteropancreatic neuroendocrine tumors after initial R0 surgical resection.

BACKGROUND: Here we describe the treatments and prognosis for metachronous metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) after initial R0 surgical resection at a large center in China. METHODS: The clinicopathological data and survival outcomes for 108 patients (median age, 54.0 years) with metachronous hepatic metastatic GEP-NETs disease who were initially treated using R0 surgical resection between August 2003 and July 2014 were analyzed using one-way comparisons, survival analysis, and a predictive nomogram. RESULTS: Fifty-five (50.9%) patients had pancreatic NETs and 92 (85.2%) had G2 primary tumors. For treatment of the hepatic metastases, 48 (44.4%) patients received liver-directed local treatment (metastasectomy, radiofrequency ablation, transcatheter arterial chemoembolization, etc.), 15 (13.9%) received systemic treatment (interferon, somatostatin analogs, etc.), and 45 (41.7%) received both treatments. Multivariable analyses revealed that OS was associated with hepatic tumor number (P < 0.001), treatment modality (P = 0.045), and elevated Ki-67 index between the metastatic and primary lesions (P = 0.027). The predictive nomogram C-index was 0.63. CONCLUSIONS: A higher Ki-67 index in metastases compared to primary tumor was an independent factor for poor prognosis. Local treatment was associated with prolonged survival of hepatic metastatic GEP-NET patients. Optimal treatment strategies based on clinicopathological characteristics should be developed.

Low birth weight contributed to increased serum IL-6 levels in infantile respiratory syncytial virus infection.

BACKGROUND: To evaluate the role of serum cytokines in the pathogenesis of respiratory syncytial virus (RSV) infection in infants with low birth weight (LBW). METHODS: A prospective observational study was performed, and hospitalized children with lower respiratory tract infection (LRTI) were recruited. Three hundred fifty-eight patients < 1 year met the inclusion criteria: 116 patients had only RSV infection (RSV group); 242 patients had no RSV or other specific pathogen (non-RSV group). Serum interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were detected through flow cytometry. RESULTS: No significant differences in serum IL-2, 4, 6, 10, and IFN-γ levels were observed between the RSV and non-RSV groups. For RSV infected infants with or without wheezing, delivery mode had no obvious effect on the changes of serum cytokine levels. However, the level of IL-6 in the RSV-infected infants with LBW was significantly higher than that in infants with normal birth weight. CONCLUSIONS: Serum IL-6 level was significantly increased in RSV infected infants with LBW. It is likely that the specific serum cytokine pattern will contribute to our understanding of the pathogenesis of RSV infections, especially in RSV-infected infants with LBW.

Serum cytokine profile contributes to discriminating M. pneumoniae pneumonia in children.

BACKGROUND: To evaluate the role of serum cytokines in discriminating M. pneumoniae infection in children with community-acquired pneumonia (CAP). METHODS: A prospective observational study was conducted. 385 hospitalized patients with CAP had only M. pneumoniae (MP group) infection; 321 hospitalized patients with CAP had no M. pneumoniae and other specific pathogen (control group) infections. Serum interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were detected by flow cytometry. RESULTS: In children younger than 5years, serum IL-6, TNF-α, and IFN-γ levels from MP group were significantly higher than those from control group. However in children 5-15years, serum IL-6, IL-10, and IFN-γ levels from MP group were significantly higher than those from control group. In the final multivariate logistic regression model for serum cytokine, moderately elevated IL-6, IL-10, and IFN-γ shows a higher prediction of development of M. pneumoniae pneumonia among CAP patients. CONCLUSIONS: A specific cytokine pattern showed a higher prediction of M. pneumoniae pneumonia among CAP patients, further suggesting that serum cytokine pattern might be useful in differentiating infectious causative agents in children.

Identification of intralocus recombinants for the mating loci of Lentinula edodes.

Mating type analysis was carried out for progeny of 13 strains of Lentinula edodes. Out of the 13 strains, one strain HL01 was found with an exceptional phenotype, in that the proportion of incompatibility to compatibility of 132 random pairings of monokaryons derived from the dikaryon was 82:50. This value differs significantly (Chi-square = 11) from the expected 3:1 ratio. The mating types of 189 monokaryons derived from the same sporocarp of HL01 were identified using four standard tester strains. Of the 189 spore monokaryons, 161 monokaryons could be classified into one of four normal mating types (A(1)B(1), A(2)B(2), A(1)B(2), and A(2)B(1)), and the other 28 monokaryons could be classified into another four groups. By crossing in all pairwise combinations, the mating types of the 28 monokaryons were further analyzed. The results indicated that intralocus recombination occurred in both A and B mating loci (matA and matB), at frequencies of 8.5 and 11.6%, respectively. The matA is composed of at least two subloci while the matB may be composed of more than two subloci. The subsequent fruiting test revealed that all compatible pairings which contained at least one of the recombinants had the ability to produce fruiting bodies.

[Relationship between expression of endothelial nitric oxide synthase and NADPH oxidase in lungs of mice exposed to chronic hypoxia].

OBJECTIVE: To explore the relationship between the expression of endothelial nitric oxide synthase (eNOS) and NADPH oxidase (NOX) in the lungs of mice treated by chronic hypoxic exposure. METHODS: Thirty male wild-type (WT) C57Bl/6 mice and thirty male eNOS-knockout (KO) C57BL/6 mice were randomly divided into normoxic groups (exposed to normoxia for 7 days or 21 days), hypoxic groups (exposed to 10% oxygen for 7 days or 21 days), and treatment groups (exposed to 10% oxygen and orally administrated 10 mmol/L 4-hydroxy TEMPO in drinking water for 7 days or 21 days) (n=6 in each group). The remodeling of the small pulmonary arteries was evaluated by the percentage of media wall thickness (MT%). The weight ratio of right ventricle to left ventricle plus septum (RV/[LV+S]) was calculated to evaluate the hypertrophy of right ventricle. Real-time PCR was used to measure the mRNA expression of NOX2, NOX4, and eNOS in mouse lungs. ELISA was used to determine the concentration of reactive oxygen species (ROS) in mouse lungs. RESULTS: In WT mice and KO mice, the hypoxic groups had significantly increased pulmonary vascular remodeling and RV/[LV+S] compared with the normoxic and treatment groups (P<0.05), but there were no significant differences between the normoxic and treatment groups (P>0.05). In WT mice, the hypoxic and treatment groups had significantly lower ROS concentrations than the normoxic group (P<0.05), but there were no significant differences between the hypoxic and treatment groups (P>0.05). In WT mice, the mRNA expression of eNOS, NOX2, and NOX4 was significantly higher in the hypoxic group than in the normoxic group (P<0.05), and 4-hydroxy TEMPO reversed their over-expression. In the normoxic group, the KO mice had significantly higher NOX2 and NOX4 mRNA expression than the WT mice (P<0.05); in KO mice, the hypoxic group showed no significant changes in NOX4 mRNA expression (P>0.05), but had significantly reduced NOX2 mRNA expression (P<0.05), as compared with the normoxic group; the treatment group had reduced expression of NOX2 mRNA expression and increased NOX4 mRNA expression (P<0.05), as compared with the hypoxic group. CONCLUSIONS: eNOS plays a key role in the regulation of expression of NOX2 and NOX4 in the lungs exposed to hypoxia. It suggests that NOX and eNOS may physically interact with one another in pulmonary vascular remodeling induced by chronic hypoxia.

Epigenetics of hyper-responsiveness to allergen challenge following intrauterine growth retardation rat.

BACKGROUND: Epidemiological studies have revealed that intrauterine growth retardation (IUGR) or low birth weight is linked to the later development of asthma. Epigenetic regulatory mechanisms play an important role in the fetal origins of adult disease. However, little is known regarding the correlation between epigenetic regulation and the development of asthma following IUGR. METHODS: An IUGR and ovalbumin (OVA)-sensitization/challenge rat model was used to study whether epigenetic mechanisms play a role in the development of asthma following IUGR. RESULTS: Maternal nutrient restriction increased histone acetylation levels of the endothelin-1 (ET-1) gene promoter in lung tissue of offspring, but did not cause significant alterations of DNA methylation. The effect was maintained until 10 weeks after birth. Furthermore, these epigenetic changes may have induced IUGR individuals to be highly sensitive to OVA challenge later in life, resulting in more significant changes related to asthma. CONCLUSIONS: These findings suggest that epigenetic mechanisms might be closely associated with the development of asthma following IUGR, providing further insight for improved prevention of asthma induced by environmental factors.

Effect of low birth weight on childhood asthma: a meta-analysis.

BACKGROUND: Low birth weight is strongly correlated with an increased risk of adult diseases. Additionally, low birth weight might be a risk factor for asthma later in life. METHODS: A systematic literature search of the PubMed database from 1966 to November 2013 was conducted. The criteria for inclusion of papers were as follows: case-control or cohort studies; the odds ratio (OR) or risk ratio (RR) estimates with the corresponding 95% confidence intervals (CIs) were presented, or there were sufficient data for calculation; and studies were published in English up to October 2013. Random-effect and fixed-effect meta-analyses, meta-regression, and cumulative meta-analysis were conducted. RESULTS: Thirteen cohort studies and 1,105,703 subjects were included. The overall pooled RRs (95% CIs) of asthma risk for low birth weight were 1.162 (fixed-effects model, 95% CI, 1.128-1.197) and 1.152 (random-effects model, 95% CI, 1.082-1.222). In stratified analyses, the effect of low birth weight on childhood asthma was strong, particularly in studies conducted in Europe, those with a small sample size, and those published recently. A meta-regression analysis did not find significant determinants. CONCLUSIONS: This meta-analysis shows that low birth weight significantly increases the risk of childhood asthma.

Three new indole alkaloid derivatives from Fissistigma oldhamii Levl. and their anti-inflammatory effects.

Three new indole alkaloid derivatives, fissindoalkas A-C (1-3) together with one known biogenetically related polysubstituted indole alkaloid (4) were isolated from the roots of Fissistigma oldhamii (Hemsl.) Merr. The structures of compounds 1-4 were elucidated using comprehensive spectroscopic methods. The inhibitory activities of compounds 1-4 against nitric oxide (NO) production induced by lipopolysaccharide (LPS) were evaluated in vitro using mouse macrophage RAW264.7 cells. Compounds 2 and 3 showed potent inhibitory activities on NO production with IC50 values of 2.52 ± 0.18 and 2.33 ± 0.16 µM. These results indicate that the discovery of indole alkaloid derivatives, from the roots of F. oldhamii, which show significant anti-inflammatory properties, could be of great importance to the research and for the development of novel natural anti-inflammatory agents.

Decreased Kv1.5 expression in intrauterine growth retardation rats with exaggerated pulmonary hypertension.

Chronic hypoxia pulmonary hypertension (CH-PHT) in adulthood is likely to be of fetal origin following intrauterine growth retardation (IUGR). Oxygen (O2)-sensitive voltage-gated potassium channels (Kv channels) in resistance pulmonary artery smooth muscle cells (PASMCs) play an important role in scaling pulmonary artery (PA) pressure. Expression and functional changes of Kv channels are determined, in part, by embryonic development. We hypothesized that O2-sensitive Kv channels play an important role in exaggerated CH-PHT following IUGR. We established a rat model of IUGR by restricting maternal food during the entire pregnancy and exposed IUGR rats and their age-matched controls aged 12 wk to hypoxia for 2 wk. We found that hypoxia exposure significantly induced increased PA pressure and thicker smooth muscle layer in the IUGR group relative to controls. We compared the constriction of the resistance PA to inhibitors of K⁺ channels, 4-aminopyridine (4-AP), tetraethylammonium, and BaCl2. Despite the thickness of the smooth muscle layer, the constriction to 4-AP was significantly reduced in the IUGR group exposed to hypoxia. Consistent with these changes in pulmonary vascular reactivity, 2 wk of hypoxia induced weaker 4-AP-sensitive Kv currents in a single IUGR PASMC. Moreover, after 2 wk of hypoxia, Kv1.5 expression in resistance PAs decreased significantly in the IUGR group. Overexpression of Kv1.5 in cultured PASMCs could offset hypoxia-induced cell proliferation and hypoxia-inhibited Kv currents in the IUGR group. These results suggest that the inhibited expression of Kv1.5 in PASMCs contribute to the development of exaggerated CH-PHT in IUGR rats during adulthood.

Epigenetics of hypoxic pulmonary arterial hypertension following intrauterine growth retardation rat: epigenetics in PAH following IUGR.

BACKGROUND: Accumulating evidence reveals that intrauterine growth retardation (IUGR) can cause varying degrees of pulmonary arterial hypertension (PAH) later in life. Moreover, epigenetics plays an important role in the fetal origin of adult disease. The goal of this study was to investigate the role of epigenetics in the development of PAH following IUGR. METHODS: The IUGR rats were established by maternal undernutrition during pregnancy. Pulmonary vascular endothelial cells (PVEC) were isolated from the rat lungs by magnetic-activated cell sorting (MACS). We investigated epigenetic regulation of the endothelin-1 (ET-1) gene in PVEC of 1-day and 6-week IUGR rats, and response of IUGR rats to hypoxia. RESULTS: The maternal nutrient restriction increased the histone acetylation and hypoxia inducible factor-1α (HIF-1α) binding levels in the ET-1 gene promoter of PVEC in IUGR newborn rats, and continued up to 6 weeks after birth. These epigenetic changes could result in an IUGR rat being highly sensitive to hypoxia later in life, causing more significant PAH or pulmonary vascular remodeling. CONCLUSIONS: These findings suggest that epigenetics is closely associated with the development of hypoxic PAH following IUGR, further providing a new insight for improved prevention and treatment of IUGR-related PAH.

Heterologous functional analysis of the Malus xiaojinensis MxIRT1 gene and the His-box motif by expression in yeast.

Malus xiaojinensis is an important, iron-efficient rootstock germplasm. Iron uptake is an elaborately controlled process in plant roots, involving specialized transporters. MxIRT1, a Fe(II) transporter gene of M. xiaojinensis, is homologous to other iron transporters at the amino acid level. In the current study, the plasmid pYES2.0-MxIRT1, containing MxIRT1 cDNA, was constructed and transformed into yeast mutants. The results indicated that it could reverse the phenotype of yeast strain DEY1453, an iron uptake mutant. Complementation tests suggested that it might not be a specific transporter, as it was able to restore the phenotypes of other yeast mutant strains, including Mn, Cu and Zn uptake mutants. The functions of the critical histidine residues in the His-box of MxIRT1 were tested by transforming mutant yeast strain DEY1453 with different His residues altered by directed mutagenesis. The His-box of MxIRT1 was found to be necessary for iron transport, with different histidine residues (H(1-4)) playing different roles in the transport.

Different mechanisms lead to convergence of reproductive strategies in two lacertid lizards (Takydromus wolteri and Eremias argus).

Life history traits may vary within and among species. Rarely, however, are both variations examined concurrently to identify the life history adaptation. We found that female body size, offspring number and size, and incubation period showed convergent evolution in two lacertid lizards (Takydromus wolteri and Eremias argus) that occur sympatrically in high-latitude and low-latitude localities. Females from the high-latitude population were larger and produced larger clutches than those from the low-latitude population. In both species, the incubation period was shorter for the high-latitude population than for the low-latitude population. However, the physiological mechanism underlying the shorter incubation period differed between the species. These results suggest that: (1) sympatric lizards may adopt similar reproductive strategies in response to their common environments, and (2) embryonic development of the two species follows different pathways for adaptation to low temperatures. This study highlights the importance of understanding the adaptive evolution of life history in response to environmental changes at the embryonic life stages.

Rational design of wettability-patterned microchips for high-performance attomolar surface-enhanced Raman detection.

Recent progress in wettability-patterned microchips has facilitated the development of ultra-trace detection in multiple biomedical and food safety fields. The existence of a superhydrophilic trap can realize targeted deposition of the analyte. However, the wetting transition from the Cassie-Baxter state to the Wenzel state usually occurs during evaporation and leads to a larger deposition footprint, which has a strong impact on the detection sensitivity and uniformity. In this paper, we report an integrated design, fabrication, and evaporation strategy to avoid the transition for high-performance attomolar surface-enhanced Raman scattering (SERS) detection. An improved force balance model was proposed to design the microstructures of wettability-patterned microchips, which were fabricated by nanosecond laser direct writing and surface fluorination. The microchips were composed of superhydrophobic micro-grooves and superhydrophilic traps, by which the targeted deposition of Au nanoparticles and rhodamine 6G (R6G) onto a minimal area of ∼70 × 70 µm2 was realized after a two-step heated evaporation. Accordingly, the detection limit was down to the attomolar level (5 × 10-18 M) with SERS enhancement factors (EFs) exceeding 1010. More importantly, the Raman signals showed good uniformity (RSD of 11.5%) for the concentration of 2 × 10-17 M. A good linear relationship was obtained in the quantitative concentration range of 10-12 M to 5 × 10-18 M with a high correlation coefficient (R2) of 0.996. These wettability-patterned microchips exhibit high performance (that is, both good sensitivity and good uniformity) in the detection of ultra-trace molecules in aqueous solutions, avoiding the need for expensive equipment and considerable skill in operations. The proposed strategy could also be applied to other microfluidic devices for rapid and simple analyte pre-concentration.

Induction of root Fe(lll) reductase activity and proton extrusion by iron deficiency is mediated by auxin-based systemic signalling in Malus xiaojinensis.

Iron is a critical cofactor for a number of metalloenzymes involved in respiration and photosynthesis, but plants often suffer from iron deficiency due to limited supplies of soluble iron in the soil. Iron deficiency induces a series of adaptive responses in various plant species, but the mechanisms by which they are triggered remain largely unknown. Using pH imaging and hormone localization techniques, it has been demonstrated here that root Fe(III) reductase activity and proton extrusion upon iron deficiency are up-regulated by systemic auxin signalling in a Fe-efficient woody plant, Malus xiaojinensis. Split-root experiments demonstrated that Fe-deprivation in a portion of the root system induced a dramatic increase in Fe(III) reductase activity and proton extrusion in the Fe-supplied portion, suggesting that the iron deficiency responses were mediated by a systemic signalling. Reciprocal grafting experiments of M. xiaojinensis with Malus baccata, a plant with no capability to produce the corresponding responses, indicate that the initiation of the systemic signalling is likely to be determined by roots rather than shoots. Iron deficiency induced a substantial increase in the IAA content in the shoot apex and supplying exogenous IAA analogues (NAA) to the shoot apex could mimic the iron deficiency to trigger the corresponding responses. Conversely, preventing IAA transport from shoot to roots blocked the iron deficiency responses. These results strongly indicate that the iron deficiency-induced physiological responses are mediated by systemic auxin signalling.

Microbulbifer marinus sp. nov. and Microbulbifer yueqingensis sp. nov., isolated from marine sediment.

Two Gram-negative, aerobic strains, Y215(T) and Y226(T), were isolated from sediment from Yueqing Bay, Zhejiang Province, China. The two novel strains were both positive for oxidase activity, nitrate reduction, and aesculin and casein decomposition, but negative for gelatin and tyrosine decomposition. Catalase activity, and starch and Tween 80 decomposition differed between the two strains. Cells of both novel strains were rod-shaped in young cultures and ovoid in older cultures. Optimum NaCl concentration and pH range for growth of both strains were 2.0-3.0% (w/v) and 7.0-8.0, respectively, whereas the optimum growth temperature for strain Y215(T) (25-30 °C) was lower than that for strain Y226(T) (30-37 °C). The genomic DNA G+C contents of strains Y215(T) and Y226(T) were 54.0 and 56.7 mol%, respectively. The major fatty acids in both isolates were iso-C(15:0) and iso-C(17:1)ω9c, which was also the case in the reference strains apart from Microbulbifer salipaludis, which possessed C(18:1)ω7c as the predominant fatty acid. The predominant isoprenoid quinone was Q-8 and the major polar lipids of both strains were phosphatidylethanolamine, phosphatidylglycerol and an unknown glycolipid. Both strains had highest 16S rRNA gene sequence similarity to members of the genus Microbulbifer. Strain Y215(T) was closely related to the type strains of Microbulbifer maritimus (97.6%) and Microbulbifer donghaiensis (97.5%), whereas strain Y226(T) was closely related to the type strain of M. salipaludis (97.6%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strains Y215(T) and Y226(T) fell into two separate clusters. The DNA-DNA relatedness values of strain Y215(T) with M. maritimus TF-17(T) and M. donghaiensis CN85(T) were 34.1 and 32.8%, respectively, whereas that between strain Y226(T) and M. salipaludis SM-1(T) was 38.0%; these values are significantly lower than the threshold value for the delineation of bacterial species. On the basis of their distinct taxonomic characteristics, the two isolates represent two novel species of the genus Microbulbifer, for which the names Microbulbifer marinus sp. nov. and Microbulbifer yueqingensis sp. nov. are proposed; the type strains are Y215(T) (=CGMCC 1.10657(T)=JCM 17211(T)) and Y226(T) (=CGMCC 1.10658(T)=JCM 17212(T)), respectively.

Efficient isolation and purification of tissue-specific protoplasts from tea plants (Camellia sinensis (L.) O. Kuntze).

BACKGROUND: Plant protoplasts constitute unique single-cell systems that can be subjected to genomic, proteomic, and metabolomic analysis. An effective and sustainable method for preparing protoplasts from tea plants has yet to be established. The protoplasts were osmotically isolated, and the isolation and purification procedures were optimized. Various potential factors affecting protoplast preparation, including enzymatic composition and type, enzymatic hydrolysis duration, mannitol concentration in the enzyme solution, and iodixanol concentration, were evaluated. RESULTS: The optimal conditions were 1.5% (w/v) cellulase and 0.4-0.6% (w/v) macerozyme in a solution containing 0.4 M mannitol, enzymatic hydrolysis over 10 h, and an iodixanol concentration of 65%. The highest protoplast yield was 3.27 × 106 protoplasts g-1 fresh weight. As determined through fluorescein diacetate staining, maximal cell viability was 92.94%. The isolated protoplasts were round and regularly shaped without agglomeration, and they were less than 20 µm in diameter. Differences in preparation, with regard to yield and viability in the tissues (roots, branches, and leaves), cultivars, and cultivation method, were also observed. CONCLUSIONS: In summary, we reported on a simple, efficient method for preparing protoplasts of whole-organ tissue from tea plant. The findings are expected to contribute to the rapid development of tea plant biology.

Metabolics and ionomics responses of tea leaves (Camellia sinensis (L.) O. Kuntze) to fluoride stress.

Tea plant (Camellia sinensis (L.) O. Kuntze) is known to accumulate high concentrations of fluoride (F) in its leaves; however, the underlying mechanism of F accumulation remains unclear. The main objective of this study was to investigate the homeostatic self-defense mechanisms of tea leaves to F supplementation (0, 5, 20, and 50 mgL-1) by metabolomics and ionomics. We identified a total of 96 up-regulated and 40 down-regulated metabolites in tea leaves treated with F. Of these different compounds, minor polypeptides, carbohydrates and amino acids played valuable roles in the F-tolerating mechanism of tea plant. After F treatments, the concentrations of sodium (Na), ferrum (Fe), manganese (Mn), and molybdenum (Mo) were significantly increased in tea leaves, whereas the aluminum (Al) was decreased. These findings suggest that the ionic balance and metabolites are attributable to the development of F tolerance, providing new insight into tea plant adaptation to F stress.

Natural variations in a pectin acetylesterase gene, MdPAE10, contribute to prolonged apple fruit shelf life.

Room-temperature shelf life is a key factor in fresh market apple (Malus domestica Borkh.) quality and commercial value. To investigate the genetic and molecular mechanism underlying apple shelf life, quantitative trait loci (QTL) were identified using bulked segregant analysis via sequencing (BSA-seq). Ethylene emission, flesh firmness, or crispness of apple fruit from 1,273 F1 plants of M. asiatica Nakai 'Zisai Pearl' × M. domestica 'Golden Delicious' were phenotyped prior to and during 6 wk of room-temperature storage. Segregation of ethylene emission and the flesh firmness or crispness traits was detected in the population. Thirteen QTL, including three major ones, were identified on chromosome 03, 08, and 16. A candidate gene encoding pectin acetylesterase, MdPAE10, from the QTL Z16.1 negatively affected fruit shelf life. A 379-bp deletion in the coding sequence of MdPAE10 disrupted its function. A single nucleotide polymorphism (SNP) in the MdPAE10 promoter region reduced its transcription activity. These findings provided insight into the genetic control of fruit shelf life and can be potentially used in apple marker-assisted selection.