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1.
《Journal of Asia》2020,23(2):260-268
Eggplant (Solanum melongena L.) is the leading vegetable grown and consumed in the Philippines, and the eggplant leafhopper is one of its most important insect pests. Nine local populations of leafhopper infesting eggplants were collected from major eggplant growing areas in Luzon Island to determine if these populations are constituted singly or by different species and to assess the level of variability among them. Morphological analysis of the adult male abdominal and genital traits and partial mitochondrial COI gene sequence identified the eggplant leafhopper populations in Luzon Island as belonging to Amrasca (=Sundapteryx) biguttula (Ishida) (Hemiptera:Cicadelliae). Observed male specimens exhibited modifications in the pregenital abdominal tergites VII and VIII that were previously reported to not be found in other Amrasca species. Principal Component Analysis of four morphometric genital traits revealed high similarity among the leafhopper populations regardless of eggplant production areas. Partial COI sequence analysis idenfitied 11 sequence variants (haplotypes), with one predominant haplotype. Overall, the leafhopper populations from Luzon Island exhibited moderate haplotype diversity and low nucleotide diversity, indicating low genetic diversity. Topologies from a maximum likelihood tree indicate all eleven haplotypes cluster in a single clade with other A. biguttula infesting cotton and potato in India, but the Philippine population forms a separate subgroup although with weak bootstrap support. Further analysis with the Generalized Mixed Yule Coalescent (GMYC) method classified the different haplotypes into a single GMYC entity.  相似文献   

2.
ObjectiveTo explore the relationship between thyroid dysfunction, thyroid-stimulating hormone (TSH) levels, and risks of atrial fibrillation (AF) in studies and conduct a dose-response meta-analysis on the correlation between the TSH levels and risk of AF.MethodsThirteen studies from 5 databases with 649 293 subjects (mean age, 65.1 years) were included. The dose-response meta-analysis was conducted by comparing the risk ratios (RRs) and 95% confidence intervals (CIs) for incident AF associated with different levels of TSH (vs TSH level of 0 mU/L) across studies. Data were collected until October 25, 2021.ResultsSubclinical hyperthyroidism, subclinical hypothyroidism, and clinical hyperthyroidism were associated with an increased risk of AF (RR, 1.70; 95% CI, 1.11-2.62; RR, 1.23; 95% CI, 1.05-1.44; and RR, 2.35; 95% CI, 1.07-5.16, respectively), whereas clinical hypothyroidism was not associated with the significantly increased risk of AF (RR, 1.20; 95% CI, 0.72-1.99). A nonlinear relationship was observed in 2 models (crude model, Pnonlinear < .001; adjusted model, Pnonlinear = .0391) between the TSH levels and risks of AF.ConclusionsOur study indicated that subclinical hyperthyroidism, subclinical hypothyroidism, clinical hyperthyroidism were associated with the risk of AF, and the results for the TSH levels and risk of AF were mixed, which showed a U-shaped relationship.  相似文献   

3.
Oral and gut Bacteroidetes produce unique classes of serine-glycine lipodipeptides and glycine aminolipids that signal through host Toll-like receptor 2. These glycine lipids have also been detected in human arteries, but their effects on atherosclerosis are unknown. Here, we sought to investigate the bioactivity of bacterial glycine lipids in mouse models of atherosclerosis. Lipid 654 (L654), a serine-glycine lipodipeptide species, was first tested in a high-fat diet (HFD)-fed Ldlr?/? model of atherosclerosis. Intraperitoneal administration of L654 over 7 weeks to HFD-fed Ldlr?/? mice resulted in hypocholesterolemic effects and significantly attenuated the progression of atherosclerosis. We found that L654 also reduced liver inflammatory and extracellular matrix gene expression, which may be related to inhibition of macrophage activation as demonstrated in vivo by lower major histocompatibility complex class II gene expression and confirmed in cell experiments. In addition, L654 and other bacterial glycine lipids in feces, liver, and serum were markedly reduced alongside changes in Bacteroidetes relative abundance in HFD-fed mice. Finally, we tested the bioactivities of L654 and related lipid 567 in chow-fed Apoe?/? mice, which displayed much higher fecal glycine lipids relative to HFD-fed Ldlr?/? mice. Administration of L654 or lipid 567 for 7 weeks to these mice reduced the liver injury marker alanine aminotransferase, but other effects seen in Ldlr?/? were not observed. Therefore, we conclude that conditions in which gut microbiome-derived glycine lipids are lost, such as HFD, may exacerbate the development of atherosclerosis and liver injury, whereas correction of such depletion may protect from these disorders.  相似文献   

4.
《Endocrine practice》2021,27(12):1225-1231
ObjectiveBone health in older individuals with HIV infection has not been well studied. This study aimed to compare bone mineral density (BMD), trabecular bone score (TBS), and bone markers between HIV-infected men and age- and body mass index (BMI)-matched HIV-uninfected men aged ≥60 years. We investigated the associations of risk factors related to fracture with BMD, TBS, and bone markers in HIV-infected men.MethodsThis cross-sectional study included 45 HIV-infected men receiving antiretroviral therapy and 42 HIV-uninfected men. Medical history, BMD and TBS measurements, and laboratory tests related to bone health were assessed in all the participants. HIV-related factors known to be associated with bone loss were assessed in the HIV-infected men.ResultsThe mean BMD, TBS, and osteopenia or osteoporosis prevalence were similar among the cases and controls. The HIV-infected men had significantly higher mean N-terminal propeptide of type 1 procollagen and C-terminal cross-linking telopeptide of type I collagen levels. Stepwise multiple linear regression analysis demonstrated that low BMI (lumbar spine, P = .015; femoral neck, P = .018; and total hip, P = .005), high C-terminal cross-linking telopeptide of type I collagen concentration (total hip, P = .042; and TBS, P = .010), and low vitamin D supplementation (TBS, P = .035) were independently associated with low BMD and TBS.ConclusionIn older HIV-infected men with a low fracture risk, the mean BMD and TBS were similar to those of the age- and BMI-matched controls. The mean bone marker levels were higher in the HIV group. Traditional risk factors for fracture, including low BMI, high C-terminal cross-linking telopeptide of type I collagen level, and low vitamin D supplementation, were significant predictors of low BMD and TBS.  相似文献   

5.
Mexico hosts the highest species richness of pines (Pinus, Pinaceae) worldwide; however, the priority areas for their conservation in the country are unknown. In this study, the ecological niche of the 50 native pine species was modeled. Then, through a multi-criteria analysis, the priority areas for the conservation of the genus Pinus were identified according to the spatial patterns of richness, geographic rareness, irreplaceability, the level of vulnerability of their habitat and the status of legal protection. The results revealed that the regions with high species richness differed from those with high endemism. Also, most pine species have undergone processes of habitat degradation, having been the endemic species the most affected. The priority areas covered regions with high species richness, high endemism, and highly degraded forests, located at mountainous portions of the Baja California Peninsula, the Sierra Madre Occidental, the Sierra Madre Oriental, the Trans-Mexican Volcanic Belt, and the Sierra Madre del Sur. A low proportion of priority areas overlapped with protected areas or terrestrial regions considered priorities for biological conservation. These results suggest that conservation efforts for this genus should be focused beyond regions with high species richness and current protected areas. Besides, the priority areas identified in this study can be the basis to create biological corridors and new protected areas, which could contribute significantly to the conservation of this genus in Mexico.  相似文献   

6.
Poly(ethylene terephthalate) (PET) is the most abundantly consumed synthetic polyester and accordingly a major source of plastic waste. The development of chemocatalytic approaches for PET depolymerization to monomers offers new options for open-loop upcycling of PET, which can leverage biological transformations to higher-value products. To that end, here we perform four sequential metabolic engineering efforts in Pseudomonas putida KT2440 to enable the conversion of PET glycolysis products via: (i) ethylene glycol utilization by constitutive expression of native genes, (ii) terephthalate (TPA) catabolism by expression of tphA2IIA3IIBIIA1II from Comamonas and tpaK from Rhodococcus jostii, (iii) bis(2-hydroxyethyl) terephthalate (BHET) hydrolysis to TPA by expression of PETase and MHETase from Ideonella sakaiensis, and (iv) BHET conversion to a performance-advantaged bioproduct, β-ketoadipic acid (βKA) by deletion of pcaIJ. Using this strain, we demonstrate production of 15.1 g/L βKA from BHET at 76% molar yield in bioreactors and conversion of catalytically depolymerized PET to βKA. Overall, this work highlights the potential of tandem catalytic deconstruction and biological conversion as a means to upcycle waste PET.  相似文献   

7.
《Endocrine practice》2021,27(11):1072-1076
ObjectiveThere is a direct bidirectional link between parathyroid hormone (PTH) and the renin-angiotensin-aldosterone system (RAAS), but few studies evaluated the RAAS in patients with primary hyperparathyroidism (PHPT), mainly biased from concomitant antihypertensive treatment.MethodsWe retrospectively evaluated a consecutive series of 130 normotensive patients with PHPT comparing aldosterone (ALD) levels and plasma renin activity (PRA) with the demographic, biochemical, or clinical features of PHPT.ResultsNo correlation was found between ALD and PRA, and the demographic, biochemical, and bone densitometry parameters in patients with PHPT without hypertension, with the exception of a negative correlation between age and serum PRA. Moreover, there was no significant correlation between PTH and ALD levels even in patients whose PTH level was >100 ng/L (P = .088).ConclusionIn our normotensive patients with PHPT, the ALD, PRA, and aldosterone/renin ratio were not correlated to PTH and calcium levels. In addition, they were neither related to PHPT clinical presentation nor renal function, vitamin D status, bone mass loss, or the presence of comorbidities such as diabetes and obesity. Further studies are needed to clarify the complex interplay between PTH and the RAAS in the modern PHPT presentation.  相似文献   

8.
PurposeThe aim of this study is to assess baseline mean leukocyte telomere length (TL) as a potential predictive factor for chemotherapy toxicity and a prognostic marker for long-term outcome in early breast cancer (BC) patients.Methods445 BC patients were selected, diagnosed between 2007 and 2010 with early BC and treated with (neo)adjuvant fluorouracil, epirubicin and cyclophosphamide (FEC) or with FEC and Docetaxel (FEC-D). RT-qPCR was performed on germline DNA samples collected at diagnosis before any treatment, to measure mean leukocyte TL. Uni- and multivariable logistic regression or Cox proportional hazard regression analyses were carried out to assess correlation between baseline TL and toxicity parameters (derived from the medical chart) or longer-term outcome.ResultsBaseline TL correlated with age as expected (p = 0.005), but not with febrile neutropenia (n = 97), left ventricular ejection fraction >10% decrease (n = 17) nor other toxicity endpoints measured (all p > 0.05). TL was neither associated with overall survival, breast cancer specific survival or distant disease-free survival (all p > 0.05).ConclusionsBaseline TL is not associated with chemotherapy-related toxicity nor long-term outcome in BC patients.  相似文献   

9.
Duckweed is recognized as a phytoremediation aquatic plant due to the production of large biomass and a high level of tolerance in stressed conditions. A laboratory experiment was conducted to investigate antioxidant response and mechanism of copper and mercury tolerance of S. polyrhiza (L.) Schleid. To understand the changes in chlorophyll content, MDA, proline, and activities of ROS-scavenging enzymes (SOD, CAT, GPOD) during the accumulation of Cu+2 and Hg+2, S. polyrhiza were exposed to various concentrations of Cu+2 (0.0–40 μM) and Hg+2 (0.0–0.4 μM). antioxidant activity initially indicated enhancing trend with application of 10 μM Cu+2; 0.2 μM Hg+2 (SOD), of 20 μM Cu+2; 0.2 μM Hg+2 (CAT) and of 10 μM Cu+2;0.2 μM Hg+2 (GPOD) and then decreased consistently up to 40 μM Cu+2 and 0.4 μM Hg+2. In the experiment chlorophyll and frond multiplication initially showed increasing tendency and decreased gradually with the application of increased metal concentration. Application of heavy metal has constantly enhanced proline and MDA content while the maximum increase was observed with the application of 40 μM Cu; 0.4 μM Hg for proline and MDA respectively. The upregulation of antioxidant enzymes and proline reveals that S. polyrhiza has strong biochemical strategies to deal with the heavy metal toxicity induced by the accumulation of Cu+2 and Hg+2.  相似文献   

10.
Delonix regia (Bojer ex Hook.) Raf., Cassia fistula L. and Lagerstroemia speciosa L. are three ornamental plants that produce colorful flowers. The present study aimed to evaluate the phytochemicals and bioactivities of methanolic extracts of flowers from Delonix regia (DrFME), Cassia fistula (CfFME), and Lagerstroemia speciosa (LsFME). The presence of ten different chemical classes in varying degrees was confirmed while qualitatively screened. During quantitative determination, LsFME possesses the highest amount of total phenolic (418.0 mg/g), flavonoid (50.8 mg/g), and tannin (256.3 mg/g) contents. The extracts showed excellent antioxidant capacity in a concentration-dependent manner with the lowest IC50 value (41.51 μg/mL) displayed by LsFME. LsFME paralyzed the experimental worms at 2.95 min and killed at 3.96 min. DrFME was found to be more effective in thrombolytic (35.5% clot lysis) and anticoagulant activities. Negligible hemolytic activity (IC50 > 200 μg/mL) found for all extracts which suggest their less potential toxicity. The in vivo experiments revealed that the CfFME has the highest analgesic (64.34% pain inhibition) activity while LsFME has the highest antidiarrheal (70.27% inhibition) and antihyperglycemic (46.94% inhibition) activities at 400 mg/kg of body weight doses. This study has shown the presence of phytochemicals and potential bioactivities which indicates the possibility of these flowers to be used as a source of phytochemicals as well as safe and effective natural medicine.  相似文献   

11.
The actinomycete Amycolatopsis japonicum is the producer of the chelating compound [S,S]-ethylenediamine-disuccinc acid (EDDS). [S,S]-EDDS is an isomer of ethylenediamine-tetraacetic acid (EDTA), an economically important chelating compound that suffers from an extremely poor degradability. Frequent use of the persistent EDTA in various industrial and domestic applications has caused an accumulation of EDTA in soil as well as in aqueous environments. As a consequence, EDTA is the highest concentrated anthropogenic compound present in water reservoirs. The [S,S]-form of EDDS has chelating properties similar to EDTA, however, in contrast to EDTA it is readily biodegradable. In order to compete with the cost-effective chemical synthesis of EDTA, we aimed to optimize the biotechnological production of [S,S]-EDDS in A. japonicum by using metabolic engineering approaches. Firstly, we integrated several copies of the [S,S]-EDDS biosynthetic genes into the chromosome of A. japonicum and replaced the native zinc responsive promoter with the strong synthetic constitutive promoter SP44*. Secondly, we increased the supply of O-phospho-serine, the direct precursor of [S,S]-EDDS. The combination of these approaches together with the optimized fermentation process led to a significant improvement in [S,S]-EDDS up to 9.8 g/L with a production rate of 4.3 mg/h/g DCW.  相似文献   

12.
Histone modifying enzymes have vital roles in the growth and survival of both parasites and humans. Targeting the epigenome can be a new strategy for the treatment of parasitic diseases. Compounds modulating histone acetylation/deacetylation have recently been reported hampering Plasmodium, Schistosoma, Leishmania, and Trypanosoma infections. Beside new histone deacetylase inhibitors, PfGCN5 and bromodomain inhibitors have been recently described to inhibit Plasmodium proliferation. Sm histone deacetylase 8 and SmSIRT2, as well as Leishmania and Trypanosoma sirtuins (SIR2rps), seem to be the most reliable targets to effectively fight the related protozoan infections. The selectivity toward parasite over mammalian cells is still an open question, and significant optimization efforts of epidrugs are still required to improve potency/selectivity and decrease toxicity. Recent reports on the alteration of cellular signaling pathways provoked by parasite infection through changes in the host acetylation/deacetylation status at gene promoters may suggest novel therapeutic strategies to treat these diseases.  相似文献   

13.
《Endocrine practice》2023,29(6):491-497
ObjectiveTo review evidence of existing and new pharmacological therapies for lowering lipoprotein(a) (Lp[a]) concentrations and their impact on clinically relevant outcomes.MethodsWe searched for literature pertaining to Lp(a) and pharmacological treatments in PubMed. We reviewed articles published between 1963 and 2020.ResultsWe found that statins significantly increased Lp(a) concentrations. Therapies that demonstrated varying degrees of Lp(a) reduction included ezetimibe, niacin, proprotein convertase subtilisin/kexin type 9 inhibitors, lipoprotein apheresis, fibrates, aspirin, hormone replacement therapy, antisense oligonucleotide therapy, and small interfering RNA therapy. There was limited data from large observational studies and post hoc analyses showing the potential benefits of these therapies in improving cardiovascular outcomes.ConclusionThere are multiple lipid-lowering agents currently being used to treat hyperlipidemia that also have a Lp(a)-lowering effect. Two RNA therapies specifically targeted to lower Lp(a) are being investigated in phase 3 clinical trials and, thus far, have shown promising results. However, evidence is lacking to determine the clinical relevance of reducing Lp(a). At present, there is a need for large-scale, randomized, controlled trials to evaluate cardiovascular outcomes associated with lowering Lp(a).  相似文献   

14.
《Endocrine practice》2022,28(11):1113-1117
ObjectiveTo assess the incidence of hyperkalemia in transgender women using spironolactone.MethodsThis was a retrospective chart review of transgender women who received gender-affirming hormone therapy that included spironolactone between January 2000 and September 2018. Forty-four participants who had paired potassium concentrations documented and were on spironolactone were included and analyzed. Study outcomes included the incidence of hyperkalemia (serum potassium concentrations > 5.0 mmol/L), the relationship between the duration of treatment and degree of hyperkalemia, and difference between serum potassium concentrations at the beginning of spironolactone treatment versus last serum potassium concentrations.ResultsThe median age of the participants was 36.5 years. The cohort was predominantly non-Hispanic White (32/44). No serum potassium concentration was >5.5 mmol/L, and all participants had serum creatinine level of <2 mg/dL. Median duration of treatment was 25 months (range 2-92 months) and 140 potassium measurements were available. The mean potassium concentration (3.87 mmol/L) before the initiation of spironolactone was lower than the mean potassium concentration (4.03 mmol/L) while on spironolactone (mean difference, 0.16 mmol/L, P = .013). The regression β, that is, the average change in potassium concentration per 1 additional month of treatment duration, was ?.001 (95% CI [?.004, .001]; P = .255) signifying no relation between treatment duration and spironolactone use.ConclusionNo participant had laboratory evidence of significant hyperkalemia (K > 5.5 mmol/L) after initiation of spironolactone. Frequent measurement of potassium concentrations might be unnecessary in transgender women taking spironolactone in patients with serum creatinine levels of <2 mg/dL.  相似文献   

15.
ObjectiveCalcium and parathyroid hormone (PTH) values are believed to have a linear relationship in patients with primary hyperparathyroidism and correlate with parathyroid gland size, with higher values predicting single-gland disease. In this modern series, these preoperative values were correlated with operative findings to determine their utility in predicting the gland involvement at parathyroid exploration.MethodsTwo thousand consecutive patients who underwent initial surgery for sporadic primary hyperparathyroidism from 2000 to 2014 were reviewed. All patients underwent a 4-gland exploration. Relationships between preoperative calcium and PTH values with the total gland volume of each patient were examined and stratified using the number of involved glands: single adenoma (SA), double adenoma (DA), and hyperplasia (H).ResultsThere were 1274 (64%) SA, 359 (18%) DA, and 367 (18%) H cases. There was a poor correlation between preoperative calcium and PTH values (R = 0.37) and both poorly correlated with the total gland volume (R < 0.40). Similarly, subgroup analysis using the number of involved glands showed poor correlation. The mean total gland volume was similar among all subgroups (SA = 1.28 cm3, DA = 1.43 cm3, and H = 1.27 cm3; P = .52), implying that individual glands were smaller in multigland disease. SA was found in 271 (53%) of patients with calcium levels of ≤10.5 mg/dL and 122 (78%) with levels of ≥12 mg/dL (P < .001).ConclusionThis is the largest series correlating preoperative calcium and PTH values with operative findings of gland size and number of diseased glands. Although a lower calcium value predicts somewhat more multigland disease, the overall poor correlation should make the parathyroid surgeon aware that gland size and multigland disease cannot be predicted by preoperative laboratory testing.  相似文献   

16.
17.
《Genomics》2022,114(4):110400
Endive (Cichorium endivia L.) is a leafy vegetable in the Asteraceae family. Sesquiterpene lactones (STLs) in endive leaves bring a bitter taste that varies between varieties. Despite their importance in breeding varieties with unique flavours, sesquiterpenoid biosynthesis pathways in endive are poorly understood. We assembled a chromosome-scale endive genome of 641 Mb with a contig N50 of 5.16 Mb and annotated 46,711 protein-coding genes. Several gene families, especially terpene synthases (TPS) genes, expanded significantly in the C. endivia genome. STLs biosynthesis-related genes and TPS genes in more bitter varieties have shown a higher level of expression, which could be attributed to genomic variations. Our results penetrate the origin and diversity of bitter taste and facilitate the molecular breeding of endive varieties with unique bitter tastes. The high-quality endive assembly would provide a reference genome for studying the evolution and diversity of Asteraceae.  相似文献   

18.
In the present study, 30 potential germplasm of oat (Avena sativa L.) were subjected to proximate, elemental, and HPLC analysis to provide a scientific basis to genetic diversity present among them. The extracts of the selected germplasms were also evaluated for their antioxidant potentials through DPPH and ABTS assays. Proximate analysis showed protein contents to be in the range 8.35–17.72% with the highest protein contents in the accession line 22,365 (17.72 ± 0.38%). The genotype-725 showed the highest carbohydrate, and dry matter (53.35 ± 0.01 and 93.50 ± 0.07% respectively) contents whereas, the germplasm-830 contained the highest fat (7.88 ± 0.12%) contents while the highest moisture contents were there in germplasm-22348 (11.95 ± 0.06%). The crude fiber contents (19.67 ± 0.19%) were found high in germplasm-832. The mentioned contents were also correlated to each other where a negative (?0.431*) correlation was noted for crude protein and carbohydrate while ash content to crude protein has a positive (0.38*) correlation. A positive and a negative correlation were there in Crude fats/crude protein (0.30*) and crude fats/moisture contents (?0.39*) respectively. Principal component analysis showed an Eigenvalue of 0.76 with a total variation of 85.01% when applied to proximate components. Based on cluster analysis to proximate composition all the oat germplasms were divided into 5 sub-clusters, where accession numbers 769 and 817 were found to be the most diverse genotypes. The elemental analysis confirmed the presence of magnesium (2.89–7.62 mg/L), sodium (3.71–8.03 mg/L), manganese (0.93–3.71 mg/L), copper (0.35–3.36 mg/L), iron (2.15–6.82 mg/L), zinc (1.30–3.37 mg/L), chromium (0.37–3.34 mg/L), and potassium (50.70–59.60 mg/L) in the selected germplasms. Principal component analysis for elemental composition showed the total variation of 73.75% with the Eigenvalue of 0.97. Cluster analysis on an elemental basis divided all the oat germplasms into 7 sub-clusters where accession numbers 769 and 22,350 were found to be the most diverse germplasm. Phytochemical analysis performed through HPLC resulted in the identification of nine possible compounds (malic acid, epigallocatechin gallate, quercetin, morin, ellagic acid, catechin hydrate, rutin, pyrogallol, and mandelic acid) in various germplasm of oat. A concentration-dependent antioxidant response was recorded when extracts were tested as an inhibitor of DPPH and ABTS free radicals. The results revealed that oat grains are a good source of nutrients, minerals, and phytochemicals that can be used as nutraceuticals and as food. The genetic differences revealed that this plant can be grown under varied environmental conditions.  相似文献   

19.
Foxtail millet (Pennisetum glaucum L.) is a vital crop that is planted as food and fodder crop around the globe. There is only limited information is present for abiotic stresses on the physiological responses to atrazine. A field experiment was conducted to investigate the effects of different atrazine dosages on the growth, fluorescence and physiological parameters i.e., malonaldehyde (MDA) and reactive oxygen species (ROS) (H2O2 and O2) in the leaves to know the extent of atrazine on oxidative damage of foxtail millet. Our experiment consisted of 0, 2.5, 12.5, 22.5 and 32.5 (mg/kg) of labeled atrazine doses on 2 foxtaill millet varieties. High doses of atrazine significantly enhanced ROS and MDA synthesis in the plant leaves. Enzymes activities like ascorbate peroxidase (APX) and peroxidase (POD) activities enhanced, while catalase (CAD) and superoxide dismutase (SOD) activities reduced with increasing atrazine concentrations. Finally atrazine doses at 32.5 mg/kg reduced chlorophyll contents, while chlorophyll (a/b) ratio also enhanced. Biomass, plant height, chlorophyll fluorescence parameters, minimal and maximal fluorescence (Fo, Fm), maximum and actual quantum yield, photochemical quenching coefficient, and electron transport rate are decreased with increasing atrazine doses.  相似文献   

20.
Legionella pneumophila, an environmental bacterium that parasitizes protozoa, causes Legionnaires’ disease in humans that is characterized by severe pneumonia. This bacterium adopts a distinct biphasic life cycle consisting of a nonvirulent replicative phase and a virulent transmissive phase in response to different environmental conditions. Hence, the timely and fine-tuned expression of growth and virulence factors in a life cycle–dependent manner is crucial for survival and replication. Here, we report that the completion of the biphasic life cycle and bacterial pathogenesis is greatly dependent on the protein homeostasis regulated by caseinolytic protease P (ClpP)-dependent proteolysis. We characterized the ClpP-dependent dynamic profiles of the regulatory and substrate proteins during the biphasic life cycle of L. pneumophila using proteomic approaches and discovered that ClpP-dependent proteolysis specifically and conditionally degraded the substrate proteins, thereby directly playing a regulatory role or indirectly controlling cellular events via the regulatory proteins. We further observed that ClpP-dependent proteolysis is required to monitor the abundance of fatty acid biosynthesis–related protein Lpg0102/Lpg0361/Lpg0362 and SpoT for the normal regulation of L. pneumophila differentiation. We also found that the control of the biphasic life cycle and bacterial virulence is independent. Furthermore, the ClpP-dependent proteolysis of Dot/Icm (defect in organelle trafficking/intracellular multiplication) type IVB secretion system and effector proteins at a specific phase of the life cycle is essential for bacterial pathogenesis. Therefore, our findings provide novel insights on ClpP-dependent proteolysis, which spans a broad physiological spectrum involving key metabolic pathways that regulate the transition of the biphasic life cycle and bacterial virulence of L. pneumophila, facilitating adaptation to aquatic and intracellular niches.  相似文献   

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