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1.
J Nanosci Nanotechnol ; 20(4): 2351-2358, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492247

RESUMO

In this study, the ordered mesoporous jar structure ZnO particles have been synthesized by template method. The cetyltrimethylammonium bromide (CTMAB) was used as the template agent, and zinc acetate dihydrate was used as zinc sources. The prepared material has ordered mesoporous on the surface. The prepared ordered mesoporous ZnO particles showed the hexagonal prisms hollow jar structure, the hexagonal prisms average diameter was about 150 nm, the average length was about 200 nm, and the jar average diameter was about 100 nm. The prepared materials were used as a gas sensor to test the toxic gas. The ordered mesoporous ZnO material showed more excellent gas sensing performances than the imporous ZnO material which was prepared without template agent by the same method. In particular, the ordered mesoporous ZnO showed a higher response to NOx, the detection limit reached to 0.5 ppm, the sensitivity reached to 66.92, and the response time was 1.08 s to 100 ppm NOx at 193 °C. The prepared material will be an excellent gas sensing matrix materials, and have a wide application prospect in gas sensors field.

2.
Psychol Med ; : 1-12, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31685046

RESUMO

BACKGROUND: The microbiota-gut-brain axis, especially the microbial tryptophan (Trp) biosynthesis and metabolism pathway (MiTBamp), may play a critical role in the pathogenesis of major depressive disorder (MDD). However, studies on the MiTBamp in MDD are lacking. The aim of the present study was to analyze the gut microbiota composition and the MiTBamp in MDD patients. METHODS: We performed shotgun metagenomic sequencing of stool samples from 26 MDD patients and 29 healthy controls (HCs). In addition to the microbiota community and the MiTBamp analyses, we also built a classification based on the Random Forests (RF) and Boruta algorithm to identify the gut microbiota as biomarkers for MDD. RESULTS: The Bacteroidetes abundance was strongly reduced whereas that of Actinobacteria was significantly increased in the MDD patients compared with the abundance in the HCs. Most noteworthy, the MDD patients had increased levels of Bifidobacterium, which is commonly used as a probiotic. Four Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologies (KOs) (K01817, K11358, K01626, K01667) abundances in the MiTBamp were significantly lower in the MDD group. Furthermore, we found a negative correlation between the K01626 abundance and the HAMD scores in the MDD group. Finally, RF classification at the genus level can achieve an area under the receiver operating characteristic curve of 0.890. CONCLUSIONS: The present findings enabled a better understanding of the changes in gut microbiota and the related Trp pathway in MDD. Alterations of the gut microbiota may have the potential as biomarkers for distinguishing MDD patients form HCs.

3.
Medicine (Baltimore) ; 98(44): e17753, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31689832

RESUMO

INTRODUCTION: Stable coronary artery disease (SCAD) is a common clinical style in patients with coronary artery disease. Inflammation and immune injury in SCAD have been proven. Current interventions can relieve patients' symptoms, but none are stable to improve the immune damage significantly. Chinese herb is used to treat stable angina pectoris as an alternative therapy. Taoren Honghua Jian granule (THJG) is a classical formula from which patients can benefit, but lack convincing evidence. Therefore, we report a protocol of high-quality randomized controlled trial. METHODS/DESIGN: We will conduct a randomized, double-blind, placebo-controlled clinical trial to assess the effect of THJG in relief of symptoms and blood immune indexes. A total of 80 patients with SCAD will be enrolled, and treated with THJG or placebo for 4 weeks. The primary outcome measurement is change of integral traditional Chinese medicine (TCM) syndrome score from baseline to 4 weeks' treatment. The 2nd outcome measurements include change of integral TCM syndrome scores from baseline to 2 weeks' treatment and another 4 weeks' follow-up, inflammation indexes at baseline and 4 weeks' treatment. It also includes Seattle Angina Questionnaire, major adverse cardiovascular events, Athens Insomnia scale, and 36-item short form health survey score from baseline to 2 weeks' and 4 weeks' treatment, and another 4 weeks' follow-up. Adverse events will be evaluated throughout the trial. DISCUSSION: The results of this trial will prove whether THJG could alleviate symptoms, control inflammation, and improve quality of life in patients with SCAD. TRIAL REGISTRATION: ChiCTR1900021772, registered 8 March, 2019.

4.
J Fish Dis ; 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31691318

RESUMO

Susceptibility of hard clams Meretrix lusoria to birnavirus (BV) infections caused by temperature variations, from a mechanistic perspective, has rarely been explored. We used a deterministic susceptible-infectious-mortality (SIM) model to derive temperature-dependent key epidemiologic parameters based on data sets of viral infections in hard clams subjected to acute temperature changes. To parameterize seasonal pattern dependence, we estimated monthly based cumulative mortality and basic reproduction numbers (R0 ) between 1997 and 2017 by way of statistical analysis. Two alternative disease control models were also proposed to assess status of controlled temperature-mediated BV infection by using, respectively, control reproduction number (RC )-control line criterion and removal strategy-based control measure. We showed that based on RC -control strategy, when temperatures ranged from 15 to 26.8°C, proportion of susceptible hard clams removed should be at least 0.22%. Based on removal-control strategy, we found that by limiting pond water temperature to 25-30°C, together with increased removal rates and periods to remove hard clams, it is better to remove hard clams from June and August to reduce both mortality rate and spread of BV. Our results can be used to monitor BV transmission potential in hard clams that will contribute to government control strategy to eradicate future BV epidemics.

6.
BMC Plant Biol ; 19(1): 462, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675987

RESUMO

BACKGROUND: Flowering time is one of the most important agronomic characteristics that ultimately determine yield potential and eco-geographical adaptation in crops. Ghd8 and Ghd7, two major flowering genes, have similar functions and large pleiotropic effects in controlling the heading date, plant height and grain yield of rice. However, these gene interactions at the genetic and molecular levels have not been determined to date. RESULTS: In this study, we investigated the genetic interaction between Ghd8 and Ghd7 by using a set of near-isogenic lines and a panel of natural germplasm accessions in rice. We found that Ghd8 affected multiple agronomic traits in a functional Ghd7-dependent manner. Both functional Ghd8 and Ghd7 are pivotal for rice photoperiod sensitivity controlled by Hd1 and Hd3a. GHD8 could form a heterotrimeric complex with HD1 and OsHAP5b to activate the transcription of Ghd7 by binding directly to the promoter region of Ghd7, which contains the CCAAT-box motif. CONCLUSIONS: The results of this study help to elucidate the genetic and molecular bases of Ghd8 and Ghd7 interactions, indicating that Ghd8 acts upstream of Ghd7 to activate its transcription, which inhibits Hd3a expression and thus affects flowering time and rice adaptation.

7.
BMC Plant Biol ; 19(1): 467, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31684873

RESUMO

BACKGROUND: Chinese hickory (Carya cathayensis) is a popular nut plant having high economic value. Grafting is applied to accelerate the transition from vegetative phase to reproductive phase. Lysine succinylation occurs frequently in the proteins associated with metabolic pathways, which may participate in the regulation of the grafting process. However, the exact regulatory mechanism underlying grafting process in Chinese hickory has not been studied at post-translational modification level. RESULTS: A comprehensive proteome-wide lysine succinylation profiling of Chinese hickory was explored by a newly developed method combining affinity enrichment and high-resolution LC-MS/MS. In total, 259 succinylation sites in 202 proteins were identified, representing the first comprehensive lysine succinylome in Chinese hickory. The succinylation was biased to occur in the cytosolic proteins of Chinese hickory. Moreover, four conserved succinylation motifs were identified in the succinylated peptides. Comparison of two grafting stages of Chinese hickory revealed that the differential expressed succinylated proteins were mainly involved in sugar metabolism, carbon fixation, amino acid metabolism and plant-pathogen interaction. Besides, seven heat shock proteins (HSPs) with 11 succinylation sites were also identified, all of which were observed to be up-regulated during the grafting process. CONCLUSIONS: Succinylation of the proteins involved in amino acid biosynthesis might be required for a successful grafting. Succinylated HSPs might play a role in stress tolerance of the grafted Chinese hickory plants. Our results can be a good resource for functional validation of the succinylated proteins and a starting point for the investigation of molecular mechanisms during lysine succinylation occurring at grafting site.

8.
Health Qual Life Outcomes ; 17(1): 167, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699088

RESUMO

BACKGROUND: To analyze the collaboration and reporting quality of the systematic reviews of social welfare in the Campbell collaboration online library. METHODS: The Campbell collaboration online library was searched for systematic reviews of social welfare and the basic information extracted in order to assess the reporting quality of systematic reviews using a MOOSE checklist. BICOMS-2 and UCINET software were used to produce the social network, and Comprehensive Meta Analysis (Version 2) and STATA 13.0 were used to analyze the related data. RESULTS: Fifty-seven systematic reviews of social welfare were included. Twenty-eight items of the included social welfare systematic reviews were rated as complete (≥70%). There were significant differences between ≤2013 and ≥ 2014 in five items. These differences were as follows: research published by one organization or more than one organization in one item, more than three authors or less than four authors in two items, and one country or more than one country in six items. It's completed about researches with more than one organization, three authors or more than one country. Some items were found to have a low reporting rate of studies published before 2014, by one organization, with less than four authors or one country, respectively. The social network of authors and organizations showed good collaboration. CONCLUSIONS: Some items could be further improved with regard to the rate of reporting systematic reviews of social welfare in the Campbell collaboration online library. This could improve the overall quality of social welfare systematic reviews.

9.
BMC Cancer ; 19(1): 1072, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703632

RESUMO

BACKGROUND: DNMT3A R882H, a frequent mutation in acute myeloid leukemia (AML), plays a critical role in malignant hematopoiesis. Recent findings suggest that DNMT3A mutant acts as a founder mutation and requires additional genetic events to induce full-blown AML. Here, we investigated the cooperation of mutant DNMT3A and NRAS in leukemogenesis by generating a double knock-in (DKI) mouse model harboring both Dnmt3a R878H and Nras G12D mutations. METHODS: DKI mice with both Dnmt3a R878H and Nras G12D mutations were generated by crossing Dnmt3a R878H knock-in (KI) mice and Nras G12D KI mice. Routine blood test, flow cytometry analysis and morphological analysis were performed to determine disease phenotype. RNA-sequencing (RNA-seq), RT-PCR and Western blot were carried out to reveal the molecular mechanism. RESULTS: The DKI mice developed a more aggressive AML with a significantly shortened lifespan and higher percentage of blast cells compared with KI mice expressing Dnmt3a or Nras mutation alone. RNA-seq analysis showed that Dnmt3a and Nras mutations collaboratively caused abnormal expression of a series of genes related to differentiation arrest and growth advantage. Myc transcription factor and its target genes related to proliferation and apoptosis were up-regulated, thus contributing to promote the process of leukemogenesis. CONCLUSION: This study showed that cooperation of DNMT3A mutation and NRAS mutation could promote the onset of AML by synergistically disturbing the transcriptional profiling with Myc pathway involvement in DKI mice.

10.
BMC Cardiovasc Disord ; 19(1): 249, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699029

RESUMO

BACKGROUND: Conventional pharmacologic therapies aim to reduce fluid overload in advanced heart failure (HF) represented by intravenous (IV) loop diuretics (LDs) have sometimes not so efficacious and been reported to have side effects such as unpredictable removal of water and sodium and electrolyte disturbance. It is not certain whether early ultrafiltration (UF) is effective than LDs in relieving edema. Given the weakness of evidence for early UF in patients with fluid overload, recommendations of UF in guidelines is considered as second-line therapy only for patients with refractory congestion, who failed to respond to LD-based strategies. METHODS: The early continuous ultrafiltration in Chinese patients with congestive heart failure (EUC-CHF) trial is an open-label, registry-based, prospective study, recruiting patients with severe acute decompensated HF who are hospitalized for HF worsening due to overt fluid overload 24 h from hospital admission. Forty patients will be enrolled to two treatment groups (n = 20 for each group). The primary outcomes are the changes of weight loss and dyspnea severity score after treatment, as well as the occurrence of clinically overt major bleeding. DISCUSSION: EUC-CHF trial was primarily designed to evaluate the efficacy and safety of early UF in patients with acute decompensated HF to reduce volume overload and improve clinical outcome. The trial aims to determine if early UF in acute HF is superior to IV LDs in clinical parameter improvement without adverse events and prevents rehospitalization up to 30 days. Also the trial is expected to establish a scoring system based on Chinese population to guide early UF treatment in appropriate patients. EUC-CHF is one of the first controlled trials tailored to determine the benefit of UF with 24 h from hospital admission. TRIAL REGISTRATION: www.chictr.org.cn, ChiCTR1800019556. Registered on 18 November 2018.

11.
BMC Psychiatry ; 19(1): 344, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694611

RESUMO

BACKGROUND: Electroconvulsive therapy (ECT) is the most rapid and effective treatment for patients with depression, ECT can achieve remarkable antidepressant effects in the initial 3-4 sessions, but significant side effects limit its use. However, recent low-charge electrotherapy (LCE) studies have demonstrated antidepressant or antipsychotic effects with significantly fewer side effects. The aim of this study is to propose a novel two-step charge set strategy for ECT treatment, referred to as Hybrid-ECT, to decrease side effects by using a low charge while preserving treatment efficacy. METHODS/DESIGN: A randomized, double-blinded, standard-controlled, parallel-group design will be carried out. We plan to enroll 112 inpatients diagnosed with depression (unipolar or bipolar) and randomly assign them to conventional ECT (control group) or to Hybrid-ECT (treatment group, 3 ECT sessions followed by LCE sessions (approximately 2.8 joules per session)). We will evaluate participants across a wide variety of domains including clinical symptoms, cognitive, psychological and functional metrics. We will also perform magnetic resonance imaging (MRI) and event-related potential (ERPs) assessments during treatment to explore brain function differences between ECT and LCE. DISCUSSION: This research proposes a simple but completely novel ECT strategy that aims to rapidly relieve depressive symptoms and minimize side effects. The mechanism of ECT and LCE will be further discussed. TRIAL REGISTRATION: Chinese Clinical Trial Registry, Number: ChiCTR1900022905 (Registration date: April 30, 2019).

12.
Cell Mol Neurobiol ; 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31605284

RESUMO

Visually guided regulation is a sophisticated and active process, whereby sensory input helps to shape ocular development. Here, we sought to investigate the potential involvement of SorCS1, an important protein in synaptic transmission in neuron, in retinal development. A form-deprivation (FD) rat model was established. Ocular variations induced by FD were examined, including changes to eye axial length and retinal thickness. Scotopic electroretinogram (ERG) was used to examine retinal function. RD-PCR assays were screened for differentially expressed genes in FD rat eyes. Immunofluorescence staining identified the expression pattern and localization of SorCS1 in rat retina, with or without FD treatment. Additionally, primary retinal neural cells were cultured and incubated with or without a light-dark cycle, and western blot and real-time PCR assays were used to examine the expression of SorCS1. Retinal neural cells were treated with recombinant SorCS1 (h-SorCS1) coated with beads in serum-free conditions to test for effects on cellular physiology and expression of neurotransmitters involved in visual development. To monitor cell viability, a CCK8 assay was employed. Our data demonstrated that FD led to ocular axial elongation and retinal thinning. ERG tests showed FD impaired electrophysiological function in rat. An age-related expression pattern of SorCS1 was observed in the rat retina, and SorCS1 was significantly up-regulated in the FD rat retina. In addition, in vitro evidence suggested a strong correlation between light exposure and SorCS1 expression. Furthermore, treatment of retinal neural cells with h-SorCS1-beads promoted cell viability, neurite outgrowth, and up-regulation of inhibitory neurotransmitter expression, which implies that over-expression of SorCS1 may cause abnormal retinal development. Our findings suggest that SorCS1 is involved in the physiological processes of light/visually guided ocular growth.

14.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(10): 970-974, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31598938

RESUMO

OBJECTIVE: To determine the frequency of chromosomal abnormalities and outcome of pregnancy for fetuses with increased nuchal translucency (NT). METHODS: Between July 2014 and February 2018, 247 fetuses with increased NT (>95th centile)were analyzed by chromosome microarray analysis (CMA). The fetuses were divided into ones with isolated increased NT (168 cases), increased NT with cystic hygroma (20 cases), increased NT with edema (12 cases) or increased NT with other abnormalities (47 cases). All couples were followed up by telephone calls. RESULTS: The rate of chromosomal abnormalities was 31.6% (78/247), which included 66 cases with chromosomal aneuploidies and 12 with copy number variants (CNVs). CNVs accounted for 31.4% (11/35) of total abnormalities among fetuses with isolated increased NT, whilst only 2.3% (1/43) of the total abnormalities among fetuses with non-isolated increased NT. Three fetuses with a normal CMA result had mental and physical retardation. Two of them were diagnosed with single gene disorders by whole exome sequencing. CONCLUSION: CMA can detect more chromosomal microdeletion/microduplications among fetuses with isolated increased NT. Furthermore, fetuses with increased NT and anegative CMA result during pregnancy cannot exclude all adverse outcomes.


Assuntos
Aberrações Cromossômicas , Análise em Microsséries , Medição da Translucência Nucal , Resultado da Gravidez , Diagnóstico Pré-Natal , Aneuploidia , Cromossomos , Variações do Número de Cópias de DNA , Edema , Feminino , Feto , Humanos , Linfangioma Cístico , Gravidez , Ultrassonografia Pré-Natal
15.
Nat Commun ; 10(1): 4899, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653878

RESUMO

The maintenance and transition of cellular states are controlled by biological processes. Here we present a gene set-based transformation of single cell RNA-Seq data into biological process activities that provides a robust description of cellular states. Moreover, as these activities represent species-independent descriptors, they facilitate the alignment of single cell states across different organisms.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31663665

RESUMO

It is crucial but challenging to reveal the kernel atom stacking mode of Au nanoclusters for understanding the nanocluster growth mechanisms and property evolution with size increase. Recently, a very important advance has been achieved: it was revealed that the kernel atoms are packed in a layer-by-layer mode along the [001]-direction with every full (001) monolayer composed of 8 gold atoms (Au 8 unit) in a series of nanoclusters having a general formula of Au 8n+4 (TBBT) 4n+8 (n is the number of Au 8 unit;TBBTH = 4-tert-butylbenzenelthiol). However, it remains unraveled whether the kernel atoms can be stacked in a non-full (defective layer) way along the [001]-direction during the growth of the series of nanoclusters and how does the kernel layer number affect the properties of these rod-like nanoclusters. Fortunately, we synthesized a novel nanocluster which was atomically precisely characterized by mass spectrometry and single-crystal X-ray crystallography, and revealed a novel layer stacking mode in which a half monolayer composed of 4 atoms (Au 4 unit) was stacked on the full monolayer along the [001]-direction. Moreover, further experiments reveal that not only the size, but also the odevity of the kernel layer number influences the properties (polarity, photoluminescence) of gold nanoclusters, which were not previously reported. The novel nanocluster obtaining also extends the previous homologue formula from Au 8n+4 (TBBT) 4n+8 to Au 4n+4 (TBBT) 2n+8 (n is the number of Au 4 unit).

17.
Small ; 15(44): e1904569, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31573771

RESUMO

Hybrid fluorescent materials constructed from organic chelating fluorescent probes and inorganic solid supports by covalent interactions are a special type of hybrid sensing platform that has gained much interest in the context of metal ion sensing applications owing to their excellent advantages, recyclability, and solubility/dispersibility in particular, as compared with single organic fluorescent molecules. In recent decades, SiO2 materials and core-shell Fe3 O4 @SiO2 nanoparticles have become important inorganic solid materials and have been used as inorganic solid supports to hybridize with organic fluorescent receptors, resulting in multifunctional fluorescent hybrid systems for potential applications in sensing and related research fields. Therefore, recent progress in various fluorescent-group-functionalized SiO2 materials is reviewed, with a focus on mesoporous silica nanoparticles and core-shell Fe3 O4 @SiO2 nanoparticles, as interesting fluorescent organic-inorganic hybrid materials for sensing applications toward essential and toxic metal ions. Selective examples of other types of silica/silicon materials, such as periodic mesoporous organosilicas, solid SiO2 nanoparticles, fibrous silica spheres, silica nanowires, silica nanotubes, and silica hollow microspheres, are also mentioned. Finally, relevant perspectives of metal-ion-sensing-oriented silica-fluorescent probe hybrid materials are provided.

18.
Elife ; 82019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31631837

RESUMO

Notch signaling regulates cell fate selection during development in multiple organs including the lung. Previous studies on the role of Notch in the lung focused mostly on Notch pathway core components or receptor-specific functions. It is unclear, however, how individual (Dll1/Dll4/Jag1/Jag2) or families of ligands (Delta/Jagged) influence differentiation of airway epithelial progenitors. Using mouse genetic models we show major differences in Jag and Dll in regulation and establishment of cell fate. Jag ligands had a major impact in balancing distinct cell populations in conducting airways, but had no role in establishment of domains and cellular abundance in the neuroendocrine (NE) microenvironment. Surprisingly, Dll ligands were crucial in restricting cell fate and size of NE bodies and showed an overlapping role with Jag in differentiation of NE-associated secretory (club) cells. These mechanisms may potentially play a role in human conditions that result in aberrant NE differentiation, including NE hyperplasias and cancer.

19.
J Cell Biochem ; 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31633244

RESUMO

PURPOSE: The aim of this study was to screen survival-related genes for glioblastoma (GBM). METHODS: GSE53733 was downloaded from Gene Expression Omnibus (GEO) database, including 16 short-term (ST), 31 intermediate (IM), and 23 long-term (LT) survivors. Analysis of variance was used to analyze the expression in three groups. The genes with P < .01 were screened as differentially expressed genes (DEGs). Soft clustering was performed using Mfuzz to mine the expression patterns of differential genes in three groups of overall survival (OS) classification. The cytoscape plugin clueGO was used for functional enrichment analysis. The protein interaction between differential genes was extracted from the STRING V10 database, and the protein-protein interaction (PPI) network was constructed and displayed with cytoscape. The hub genes were verified by quantitative reverse-transcription polymerase chain reaction. RESULTS: Total 662 DEGs were obtained among three groups and enriched in 12 clusters. The overlap analysis between clusters could classify these 12 clusters Cluster A and B. Total 264 OS.DEGs were contained in Cluter A and Cluster B, and enriched in 28 Gene Ontology terms, such as trophoblast giant cell differentiation (P value = 6.18E-04), muscle fiber development (P value = 9.09E-04), and negative regulation of stem cell differentiation (P value = 1.76E-03). The top five nodes with highest degree in OS.PPI were HDAC1, DECR1, RASL11A, PDIA3, and POLR2F. The expression of DECR1 and POLR2F was significantly lower, while the levels of HDAC1 and PDIA3 were highly expressed in GBM tissues. CONCLUSION: DECR1, POLR2F, HDAC1, and PDIA3 might be potential key genes affected the overall survival time of patients with GBM.

20.
Plant Sci ; 289: 110275, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31623777

RESUMO

Owing to the high leaf mass per area, alpine evergreen sclerophyllous Rhododendron have low values of mesophyll conductance (gm). The resulting low chloroplast CO2 concentration aggravates photorespiration, which requires a higher ATP/NADPH ratio. However, the significance of photorespiration and underlying mechanisms of energy balance in these species are little known. In this study, eight alpine evergreen sclerophyllous Rhododendron species grown in a common garden were tested for their gm, electron flow to photorespiration, and energy balancing. Under saturating light, gm was the most limiting factor for net photosynthesis (AN) in all species, and the species differences in AN were primarily driven by gm rather than stomatal conductance. The total electron flow through photosystem II (ETRII) nearly equaled the electron transport required for Rubisco carboxylation and oxygenation. Furthermore, blocking electron flow to photosystem I with appropriate inhibitors showed that electron flow to plastic terminal oxidase was not observed. As a result, these studied species showed little alternative electron flow mediated by water-water cycle or plastic terminal oxidase. By comparison, the ratio of electron transport consumed by photorespiration to ETRII (JPR/ETRII), ranging from 43%∼55%, was negatively correlated to AN and gm. Furthermore, the increased ATP production required by enhanced photorespiration was regulated by cyclic electron flow around photosystem I. These results indicate that photorespiration is the major electron sink for dissipation of excess excitation energy in the alpine evergreen sclerophyllous Rhododendron species. The coordination of gm, photorespiration and cyclic electron flow is important for sustaining leaf photosynthesis.

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