Transcription factor PbNAC71 regulates xylem and vessel development to control plant height.

Dwarfism is an important agronomic trait in fruit breeding programs. However, the germplasm resources required to generate dwarf pear (Pyrus spp.) varieties are limited. Moreover, the mechanisms underlying dwarfism remain unclear. In this study, "Yunnan" quince (Cydonia oblonga Mill.) had a dwarfing effect on "Zaosu" pear. Additionally, the dwarfism-related NAC transcription factor gene PbNAC71 was isolated from pear trees comprising "Zaosu" (scion) grafted onto "Yunnan" quince (rootstock). Transgenic Nicotiana benthamiana and pear OHF-333 (Pyrus communis) plants overexpressing PbNAC71 exhibited dwarfism, with a substantially smaller xylem and vessel area relative to the wild-type controls. Yeast one-hybrid, dual-luciferase, chromatin immunoprecipitation-qPCR, and electrophoretic mobility shift assays indicated that PbNAC71 downregulates PbWalls are thin 1 expression by binding to NAC-binding elements in its promoter. Yeast two-hybrid assays showed that PbNAC71 interacts with the E3 ubiquitin ligase PbRING finger protein 217 (PbRNF217). Furthermore, PbRNF217 promotes the ubiquitin-mediated degradation of PbNAC71 by the 26S proteasome, thereby regulating plant height as well as xylem and vessel development. Our findings reveal a mechanism underlying pear dwarfism and expand our understanding of the molecular basis of dwarfism in woody plants.

Rapid identification of methicillin-resistant Staphylococcus aureus by MALDI-TOF MS: A meta-analysis.

Invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with high mortality and morbidity. The sooner the pathogen is determined, the better it is beneficial to patient. However, routine laboratory inspections are time-consuming and laborious. A thorough research was conducted in PubMed and Web of Science (until June 2021) to identify studies evaluating the accuracy of MRSA identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). STATA 15.0 software was used to analyze the pooled results of sensitivity, specificity, and 95% confidence intervals (CI). The summary receiver operating characteristic curves (SROC) and area under the curve (AUC) were utilized to show the overall performance of MALDI-TOF MS. Fifteen studies involving 2471 isolates were included in this study after the final selection in this meta-analysis. Using the random effects model forest plot to summarize the overall statistics, the sensitivity of MALDI-TOF MS for identifying MRSA was 92% (95% CI: 81%-97%), and the specificity was 97% (95% CI: 89%-99%). In the SROC curve, the AUC reached 0.99 (95% CI: 97%-99%). Deeks' test showed no significant publication bias in this meta-analysis. Compared with clinical reference methods, MALDI-TOF MS identification of MRSA shows a higher degree of sensitivity and specificity.

PbXND1 Results in a Xylem-Deficient Dwarf Phenotype through Interaction with PbTCP4 in Pear (Pyrus bretschneideri Rehd.).

Dwarfing is an important agronomic characteristic in fruit breeding. However, due to the lack of dwarf cultivars and dwarf stocks, the dwarfing mechanism is poorly understood in pears. In this research, we discovered that the dwarf hybrid seedlings of pear (Pyrus bretschneideri Rehd.), 'Red Zaosu,' exhibited a xylem-deficient dwarf phenotype. The expression level of PbXND1, a suppressor of xylem development, was markedly enhanced in dwarf hybrid seedlings and its overexpression in pear results in a xylem-deficient dwarf phenotype. To further dissect the mechanism of PbXND1, PbTCP4 was isolated as a PbXND1 interaction protein through the pear yeast library. Root transformation experiments showed that PbTCP4 promotes root xylem development. Dual-luciferase assays showed that PbXND1 interactions with PbTCP4 suppressed the function of PbTCP4. PbXND1 expression resulted in a small amount of PbTCP4 sequestration in the cytoplasm and thereby prevented it from activating the gene expression, as assessed by bimolecular fluorescence complementation and co-location analyses. Additionally, PbXND1 affected the DNA-binding ability of PbTCP4, as determined by utilizing an electrophoretic mobility shift assay. These results suggest that PbXND1 regulates the function of PbTCP4 principally by affecting the DNA-binding ability of PbTCP4, whereas the cytoplasmic sequestration of PbTCP4 is only a minor factor. Taken together, this study provides new theoretical support for the extreme dwarfism associated with the absence of xylem caused by PbXND1, and it has significant reference value for the breeding of dwarf varieties and dwarf rootstocks of the pear.

Downstream of GA4, PbCYP78A6 participates in regulating cell cycle-related genes and parthenogenesis in pear (Pyrus bretshneideri Rehd.).

BACKGROUND: Parthenocarpy results in traits attractive to both consumers and breeders, and it overcomes the obstacle of self-incompatibility in the fruit set of horticultural crops, including pear (Pyrus bretshneider). However, there is limited knowledge regarding the genetic and molecular mechanisms that regulate parthenogenesis. RESULTS: Here, in a transcriptional comparison between pollination-dependent fruit and GA4-induced parthenocarpy, PbCYP78A6 was identified and proposed as a candidate gene involved in parthenocarpy. PbCYP78A6 is similar to Arabidopsis thaliana CYP78A6 and highly expressed in pear hypanthia. The increased PbCYP78A6 expression, as assessed by RT-qPCR, was induced by pollination and GA4 exposure. The ectopic overexpression of PbCYP78A6 contributed to parthenocarpic fruit production in tomato. The PbCYP78A6 expression coincided with fertilized and parthenocarpic fruitlets development and the expression of fruit development-related genes as assessed by cytological observations and RT-qPCR, respectively. PbCYP78A6 RNA interference and overexpression in pear calli revealed that the gene is an upstream regulator of specific fruit development-related genes in pear. CONCLUSIONS: Our findings indicate that PbCYP78A6 plays a critical role in fruit formation and provide insights into controlling parthenocarpy.

PbWRKY75 promotes anthocyanin synthesis by activating PbDFR, PbUFGT, and PbMYB10b in pear.

Anthocyanins are common secondary metabolites in plants that impart red coloration to fruits and flowers. The important WRKY transcription factor family plays multifaceted roles in plant growth and development. In this study, we found a WRKY family gene, Pyrus bretschneideri WRKY75, that may be involved in anthocyanin synthesis in pear. Unlike Arabidopsis thaliana WRKY75, PbWRKY75 may be a positive regulator of anthocyanin synthesis. A transient expression assay indicated that PbWRKY75 promoted pear anthocyanin synthesis. The structural genes (PbANS, PbDFR, and PbUFGT) and positive regulators (PbMYB10 and PbMYB10b) of anthocyanin synthesis were significantly upregulated in the fruitlet skins of PbWRKY75-overexpressing "Zaosu" pears. Subsequently, yeast one-hybrid and dual-luciferase assays indicated that PbWRKY75 promoted PbDFR, PbUFGT, and PbMYB10b expression by activating their promoters. These results revealed that PbWRKY75 may promote the expression of both PbMYB10b and anthocyanin late biosynthetic genes (PbDFR and PbUFGT) by activating their promoters, thereby inducing anthocyanin synthesis in pear. This study enhanced our understanding of the mechanism of pear anthocyanin synthesis, which will be beneficial in the improvement of pear peel color.

Psychological distress surveillance and related impact analysis of hospital staff during the COVID-19 epidemic in Chongqing, China.

BACKGROUND: Hospital staff are vulnerable and at high risk of novel coronavirus disease (COVID-19) infection. The aim of this study was to monitor the psychological distress in hospital staff and examine the relationship between the psychological distress and possible causes during the COVID-19 epidemic. METHODS: An online survey was conducted from February 1 to February 14, 2020. Hospital staff from five national COVID-19 designated hospitals in Chongqing participated. Data collected included demographics and stress responses to COVID-19: 1) the impact of event scale to measure psychological stress reactions; 2) generalizedanxietydisorder 7 to measure anxiety symptoms; 3) Patient Health Questionnaire 9 to measure depression symptoms; 4) Yale-Brown Obsessive-Compulsive Scale to measure obsessive-compulsive symptoms (OCS); and 5) Patient Health Questionnaire 15 to measure somatization symptoms. Multiple logistic regression analysis was used to identify factors that were correlated with psychological distress. RESULTS: Hospital staff that participated in this study were identified as either doctors or nurses. A total of 456 respondents completed the questionnaires with a response rate of 91.2%. The mean age was 30.67 ± 7.48 years (range, 17 to 64 years). Of all respondents, 29.4% were men. Of the staff surveyed, 43.2% had stress reaction syndrome. The highest prevalence of psychological distress was OCS (37.5%), followed by somatization symptoms (33.3%), anxiety symptoms (31.6%), and depression symptoms (29.6%). Univariate analyses indicated that female subjects, middle aged subjects, subjects in the low income group, and subjects working in isolation wards were prone to experience psychological distress. Multiple logistic regression analysis showed "Reluctant to work or considered resignation" (odds ratio [OR], 5.192; 95%CI, 2.396-11.250; P < .001), "Afraid to go home because of fear of infecting family" (OR, 2.099; 95%CI, 1.299-3.391; P = .002) "Uncertainty about frequent modification of infection and control procedures" (OR, 1.583; 95%CI, 1.061-2.363; P = .025), and"Social support" (OR, 1.754; 95%CI, 1.041-2.956; P = .035) were correlated with psychological reactions. "Reluctant to work or considered resignation" and "Afraid to go home because of fear of infecting family" were associated with a higher risk of symptoms of Anxiety (OR, 3.622; 95% CI, 1.882-6.973; P < .001; OR, 1.803; 95% CI, 1.069-3.039; P = .027), OCS (OR, 5.241; 95% CI, 2.545-10.793; P < .001; OR, 1.999; 95% CI, 1.217-3.282; P = .006) and somatization (OR, 5.177; 95% CI, 2.595-10.329; P < .001; OR, 1.749; 95% CI, 1.051-2.91; P = .031). "Stigmatization and rejection in neighborhood because of hospital work", "Reluctant to work or considered resignation" and "Uncertainty about frequent modification of infection and control procedures" were associated with a higher risk of symptoms of Depression(OR, 2.297; 95% CI, 1.138-4.637; P = .020; OR, 3.134; 95% CI, 1.635-6.006; P = .001; OR, 1.645; 95% CI, 1.075-2.517; P = .022). CONCLUSIONS: Hospital staff showed different prevalence of psychological distress during the COVID-19 epidemic. Our study confirmed the severity of negative psychological distress on hospital staff and identified factors associated with negative psychological distress that can be used to provide valuable information for psychological interventions to improve the mental health of vulnerable groups during the COVID-19 epidemic.

2,4-D-induced parthenocarpy in pear is mediated by enhancement of GA4 biosynthesis.

Parthenocarpy, the productions of seedless fruit without pollination or fertilization, is a potentially desirable trait in many commercially grown fruits, especially in pear, which is self-incompatible. Phytohormones play important roles in fruit set, a process crucial for parthenocarpy. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D), an artificially synthesized plant growth regulator with functions similar to auxin, was found to induce parthenocarpy in pear. Histological observations revealed that 2,4-D promoted cell division and expansion, which increased cortex thickness, but the effect was weakened by paclobutrazol (PAC), a gibberellin (GA) biosynthesis inhibitor. Phenotypic differences in pear may therefore be due to different GA contents. Hormone testing indicated that 2,4-D mainly induced the production of bioactive GA4 , rather than GA3. Three key oxidase genes function in the GA biosynthetic pathway: GA20ox, GA3ox and GA2ox. In a pear group treated with only 2,4-D, PbGA20ox2-like and PbGA3ox-1 were significantly upregulated. When treated with 2,4-D supplemented with PAC, however, expression levels of these genes were significantly downregulated. Additionally, PbGA2ox1-like and PbGA2ox2-like expression levels were significantly downregulated in pear treated with either 2,4-D only or 2,4-D supplemented with PAC. We thus hypothesize that 2,4-D can induce parthenocarpy by enhancing GA4 biosynthesis.

Intestinal bacteria-a powerful weapon for fungal infections treatment.

The morbidity and mortality of invasive fungal infections are rising gradually. In recent years, fungi have quietly evolved stronger defense capabilities and increased resistance to antibiotics, posing huge challenges to maintaining physical health. Therefore, developing new drugs and strategies to combat these invasive fungi is crucial. There are a large number of microorganisms in the intestinal tract of mammals, collectively referred to as intestinal microbiota. At the same time, these native microorganisms co-evolve with their hosts in symbiotic relationship. Recent researches have shown that some probiotics and intestinal symbiotic bacteria can inhibit the invasion and colonization of fungi. In this paper, we review the mechanism of some intestinal bacteria affecting the growth and invasion of fungi by targeting the virulence factors, quorum sensing system, secreting active metabolites or regulating the host anti-fungal immune response, so as to provide new strategies for resisting invasive fungal infection.

'Yunnan' quince rootstock promoted flower bud formation of 'Abbé Fetel' pear by altering hormone levels and PbAGL9 expression.

Flower busd formation is an important plant growth process. It has been reported that dwarfing rootstocks can significantly affect the flower bud formation of scions. In this study, we found the dwarfing rootstock 'Yunnan' quince could significantly increase the flowering rate of 'Abbé Fetel' pear scions. The RNA-sequencing data revealed significant changes in the expression of genes related to hormone pathways. Furthermore, hormone analyses indicated that 'Yunnan' quince significantly decreased the GA3 content and increased the cytokinin/auxin ratio in 'Abbé Fetel' pear apical buds. The hormone contents were consistent with the RNA-sequencing data. Moreover, we found the flower development-related genes PbAGL9 and PbCAL-A1 were significantly upregulated and PbTFL1 was significantly downregulated in 'Abbé Fetel'/'Yunnan' quince apical buds. To further clarify the relationship between hormones and flowering-related genes, a hormone response assay was carried out. We found the expression levels of PbCAl-A1, PbTFL1 and PbAGL9 were regulated by hormones including GA3, CPPU and NAA. Y1H and dual-luciferase assays indicated that PbAGL9 significantly decreased the promoter activity of PbTFL1. In summary, 'Yunnan' quince upregulated PbCAL-A1 and PbAGL9, and downregulated PbTFL1 expression by decreasing the GA3 content and increasing the cytokinin/auxin ratio in 'Abbé Fetel' pear apical buds. Additionally, 'Yunnan' quince down-regulate PbTFL1 by upregulating the expression of PbAGL9, and eventually promoted floral induction in 'Abbé Fetel' pear.

Inhibitory effects of a maleimide compound on the virulence factors of Candida albicans.

Candidiasis caused by Candida albicans infection has long been a serious human health problem. The pathogenicity of C. albicans is mainly due to its virulence factors, which are novel targets of antifungal drugs for low risk of resistance development. In this study, we identified a maleimide compound [1-(4-methoxyphenyl)-1hydro-pyrrole-2,5-dione, MPD] that exerts effective anti-virulence activity. It could inhibit the process of adhesion, filamentation, and biofilm formation in C. albicans. In addition, it exhibited low cytotoxicity, hemolytic activity, and drug resistance development. Moreover, in Galleria mellonella-C. albicans (in vivo) infection model, the survival time of infected larvae was significantly prolonged under the treatment of MPD. Further, mechanism research revealed that MPD increased farnesol secretion by upregulating the expression of Dpp3. The increased farnesol inhibited the activity of Cdc35, which then decreased the intracellular cAMP content resulting in the inhibition of virulence factors via the Ras1-cAMP-Efg1 pathway. In all, this study evaluated the inhibitory effect of MPD on various virulence factors of C. albicans and identified the underlying mechanisms. This suggests a potential application of MPD to overcome fungal infections in clinics.

Accelerating the degradation of green plant waste with chemical decomposition agents.

Degradation of green plant waste is often difficult, and excess maturity times are typically required. In this study, we used lignin, cellulose and hemicellulose assays; scanning electron microscopy; infrared spectrum analysis and X-ray diffraction analysis to investigate the effects of chemical decomposition agents on the lignocellulose content of green plant waste, its structure and major functional groups and the mechanism of accelerated degradation. Our results showed that adding chemical decomposition agents to Ficus microcarpa var. pusillifolia sawdust reduced the contents of lignin by 0.53%-11.48% and the contents of cellulose by 2.86%-7.71%, and increased the contents of hemicellulose by 2.92%-33.63% after 24 h. With increasing quantities of alkaline residue and sodium lignosulphonate, the lignin content decreased. Scanning electron microscopy showed that, after F. microcarpa var. pusillifolia sawdust was treated with chemical decomposition agents, lignocellulose tube wall thickness increased significantlyIncreases of 29.41%, 3.53% and 34.71% were observed after treatment with NaOH, alkaline residue and sodium lignosulphonate, respectively. Infrared spectroscopy showed that CO and aromatic skeleton stretching absorption peaks were weakened and the C-H vibrational absorption peak from out-of-plane in positions 2 and 6 (S units) (890-900 cm(-1)) was strengthened after F. microcarpa var. pusillifolia sawdust was treated with chemical decomposition agents, indicating a reduction in lignin content. Several absorption peaks [i.e., C-H deformations (asymmetry in methyl groups, -CH(3)- and -CH(2)-) (1450-1460 cm(-1)); Aliphatic C-H stretching in methyl and phenol OH (1370-1380 cm(-1)); CO stretching (cellulose and hemicellulose) (1040-1060 cm(-1))] that indicate the presence of a chemical bond between lignin and cellulose was reduced, indicating that the chemical bond between lignin and cellulose had been partially broken. X-ray diffraction analysis showed that NaOH, alkaline residue and sodium lignosulphonate can reduce the relative crystallinity of lignocellulose in F. microcarpa var. pusillifolia by 2.64%, 13.24%, 12.44%, respectively. The C-H vibrational absorption peak from out-of-plane in positions 2 and 6 (S units) comes from the vibration of the sugar anomeric carbon. Because lignin is a phenolic, not carbohydrate polymer, the relative absorption intensity of this peak should be stronger at lower lignin contents. Compared to CK, the peak intensities increased in treatments T1, T5 and T9, indicating reduced lignin contents and increased sugar contents after CDA treatment.

Effectiveness and safety of endoscopic treatment for duodenal variceal bleeding: a systematic review.

Duodenal varix is a rare condition that involves massive bleeding, diagnostic difficulties, and a high rate of rebleeding and mortality. The purpose of this study was to systematically review endoscopic treatment for duodenal variceal bleeding to evaluate its effectiveness and safety. We searched PubMed, Embase, Web of Science, and the Cochrane Library up to 21 November 2019. Ninety-two studies containing 156 patients were finally included, and individual data from 101 patients (mean age: 52.67 ± 13.82 years, male: 64.4%) were collected and further analyzed. We used an analysis of variance and χ2 or Fisher's exact tests to analyze individual data from 101 patients. The cause of duodenal variceal bleeding was cirrhosis-related intrahepatic portal hypertension (IPH) in 76.2% of patients. The overall rates of initial hemostasis and treatment success of endoscopic treatment for duodenal variceal bleeding were 89.1 and 81.2%, respectively. The median duration of follow-up was 4.5 (1.0, 12.0) months. The overall rates of rebleeding and mortality were 8.9 and 13.9%, respectively. Among a variety of endoscopic treatments available, only the initial hemostasis rate was significantly different between the endoscopic injection sclerotherapy and endoscopic tissue adhesive (ETA) groups (72.7 vs. 94.7%, P = 0.023); differences in treatment success, rebleeding, mortality, and adverse events were not statistically significant among the four groups. Endoscopic intervention is a feasible, well tolerated, and effective modality for the treatment of duodenal variceal bleeding. Among the variety of endoscopic treatments available, ETA with cyanoacrylate may be preferable for duodenal variceal bleeding.

PbEIL1 acts upstream of PbCysp1 to regulate ovule senescence in seedless pear.

Numerous environmental and endogenous signals control the highly orchestrated and intricate process of plant senescence. Ethylene, a well-known inducer of senescence, has long been considered a key endogenous regulator of leaf and flower senescence, but the molecular mechanism of ethylene-induced ovule senescence has not yet been elucidated. In this study, we found that blockage of fertilization caused ovule abortion in the pear cultivar '1913'. According to transcriptome and phytohormone content data, ethylene biosynthesis was activated by pollination. At the same time, ethylene overaccumulated in ovules, where cells were sensitive to ethylene signals in the absence of fertilization. We identified a transcription factor in the ethylene signal response, ethylene-insensitive 3-like (EIL1), as a likely participant in ovule senescence. Overexpression of PbEIL1 in tomato caused precocious onset of ovule senescence. We further found that EIL1 could directly bind to the promoter of the SENESCENCE-ASSOCIATED CYSTEINE PROTEINASE 1 (PbCysp1) gene and act upstream of senescence. Yeast one-hybrid and dual-luciferase assays revealed the interaction of the transcription factor and the promoter DNA sequence and demonstrated that PbEIL1 enhanced the action of PbCysp1. Collectively, our results provide new insights into how ethylene promotes the progression of unfertilized ovule senescence.

Prognostic Signatures of Metabolic Genes and Metabolism-Related Long Non-coding RNAs Accurately Predict Overall Survival for Osteosarcoma Patients.

In this study, we identified eight survival-related metabolic genes in differentially expressed metabolic genes by univariate Cox regression analysis based on the therapeutically applicable research to generate effective treatments (n = 84) data set and genotype tissue expression data set (n = 396). We also constructed a six metabolic gene signature to predict the overall survival of osteosarcoma (OS) patients using least absolute shrinkage and selection operator (Lasso) Cox regression analysis. Our results show that the six metabolic gene signature showed good performance in predicting survival of OS patients and was also an independent prognostic factor. Stratified correlation analysis showed that the metabolic gene signature accurately predicted survival outcomes in high-risk and low-risk OS patients. The six metabolic gene signature was also verified to perform well in predicting survival of OS patients in an independent cohort (GSE21257). Then, using univariate Cox regression and Lasso Cox regression analyses, we identified an eight metabolism-related long noncoding RNA (lncRNA) signature that accurately predicts overall survival of OS patients. Gene set variation analysis showed that the apical surface and bile acid metabolism, epithelial mesenchymal transition, and P53 pathway were activated in the high-risk group based on the eight metabolism-related lncRNA signature. Furthermore, we constructed a competing endogenous RNA (ceRNA) network and conducted immunization score analysis based on the eight metabolism-related lncRNA signature. These results showed that the six metabolic gene signature and eight metabolism-related lncRNA signature have good performance in predicting the survival outcomes of OS patients.

PbGA20ox2 Regulates Fruit Set and Induces Parthenocarpy by Enhancing GA4 Content.

Fruit set and development occur following successful fertilization. Parthenocarpy, a valuable trait in some self-incompatible species, produces seedless fruit without fertilization. Gibberellin (GA) is a crucial hormone in fruit-set regulation and development. While investigating the development of parthenocarpy in pear (Pyrus bretschneideri Rehd.), we determined that GA 20-oxidases (GA20ox) may play key roles in seedless pear fruit development. Sequence analysis revealed three PbGA20ox genes: PbGA20ox1, PbGA20ox2, and PbGA20ox3. We analyzed the expression patterns of candidate genes and found that PbGA20ox2 levels significantly changed in pollinated fruits. Tissue-specific expression assays revealed that PbGA20ox2 is highly expressed in young fruit and leaves. Subcellular localization assays showed it was located in the cytoplasm, nucleus, and plasma membrane. Overexpressed PbGA20ox2 tomato plants were taller and had longer hypocotyls and internodes, and the emasculated flowers produced parthenocarpic fruit. In pear, the transient overexpression of PbGA20ox2 promoted fruit development and delayed the drop of nonpollinated fruit. Furthermore, the fruit of PbGA20ox2-overexpressing tomato and transient PbGA20ox2-overexpressing pear had increased GA4 (but not GA3 and GA1) contents. This result provided evidence that PbGA20ox2 was necessary for GA4-dependent pear fruit development. Our study revealed that PbGA20ox2 altered the GA biosynthetic pathway and enhanced GA4 synthesis, thereby promoting fruit set and parthenocarpic fruit development.

CPPU may induce gibberellin-independent parthenocarpy associated with PbRR9 in 'Dangshansu' pear.

Parthenocarpy is a valuable trait in self-incompatible plants, such as pear. N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU), a synthetic cytokinin analog, can induce parthenocarpy in pear (Pyrus spp.), but the mechanism of induction is unclear. To investigate the role of gibberellin in CPPU-induced parthenocarpy in pear, CPPU supplemented with paclobutrazol (PAC) was sprayed onto 'Dangshansu' pear. We found that the fruit set rate of pear treated with CPPU supplemented with PAC was identical to that in a CPPU-alone treatment group. In regard to cell development, CPPU mainly promoted hypanthium cell division and expansion, and PAC application had no influence on CPPU-induced cell development. RNA sequencing revealed that gibberellin 20 oxidase and gibberellin 3 oxidase genes were not differentially expressed following CPPU treatment. According to the analysis of fruit phytohormone content, the CPPU treatments did not induce gibberellin biosynthesis. These results suggest that CPPU-induced parthenocarpy may be gibberellin independent in 'Dangshansu' pear. After CPPU treatment, the indole acetic acid (IAA) content in fruit was significantly increased, and the abscisic acid (ABA) content was significantly decreased. Similarly, RNA sequencing revealed that many genes involved in the auxin and ABA pathways were significantly differentially expressed in the CPPU treatment groups; among them, indole-3-pyruvate monooxygenase (YUCCA) was significantly upregulated and 9-cis-epoxycarotenoid dioxygenase (NCED) was significantly downregulated. IAA and ABA may thus play important roles in CPPU-induced parthenocarpy. PbTwo-component response regulator9 (PbRR9), PbYUCCA4, and PbNCED6 were then selected to further elucidate the mechanism of CPPU-induced parthenocarpy. A yeast one-hybrid assay indicated that PbRR9 can combine with the PbYUCCA4 and PbNCED6 promoters. Dual luciferase assays revealed that PbRR9 can promote and repress the activities of the PbYUCCA4 and PbNCED6 promoters, respectively. After the transient expression of PbRR9 in fruits, PbYUCCA4 expression was significantly upregulated, and PbNCED6 expression was significantly downregulated. This study uncovered a CPPU-induced parthenocarpy mechanism that is different from that in tomato. CPPU may upregulate PbYUCCA4 and downregulate PbNCED6 by upregulating PbRR9, thereby increasing IAA content and decreasing ABA content to ultimately induce parthenocarpy in 'Dangshansu' pear. However, because only a single time point was used and because 'botanical' and 'accessory' fruits have different structures, this conclusion is still preliminary.

Efficacy and safety of sodium-glucose cotransporter-2 inhibitors in type 2 diabetes mellitus with inadequate glycemic control on metformin: a meta-analysis.

OBJECTIVES: To provide a meta-analysis of the clinical efficacy and safety of sodium glucose co-transporter 2 inhibitors (SGLT2-i), as a combination treatment with metformin in type 2 diabetes mellitus (T2DM) patients with inadequate glycemic control with metformin alone. MATERIALS AND METHODS: We have searched randomized controlled trials (RCTs) in the database: MEDLINE, Embase and Cochrane Collaborative database. We used mean differences (MD) to assess the efficacy of glycemic and other clinical parameters, and risk ratios (RR) to evaluate the adverse events for safety endpoints. The heterogeneity was evaluated by I2. RESULTS: Finally 9 studies were included. SGLT2-i plus metformin had higher reduction level in HbA1C [MD = -0.50, 95% CI (-0.62, -0.38), p < 0.00001], FPG [MD = -1.12, 95%CI (-1.38, -0.87), p < 0.00001], body weight [MD = -1.72, 95% CI (-2.05, -1.39), p < 0.00001], SBP [MD = -4.44, 95% CI (-5.45, -3.43), p < 0.00001] and DBP [MD = -1.74, 95% CI (-2.40, -1.07), p < 0.00001] compared with metformin monotherapy. However, SGLT2-i plus metformin group had higher risk of genital infection [RR = 3.98, 95% CI (2.38, 6.67), p < 0.00001]. No significant difference was found in the risk of hypoglycemia, urinary tract infection or volume related adverse events. CONCLUSIONS: Although the risk of genital infection may increase, SGLT2-i plus metformin may provide an attractive treatment option to those T2DM patients who are unable to achieve glycemic control with metformin alone, based on its effects on glycemic control, reducing body weight and lowering blood pressure.

Differences among the Anthocyanin Accumulation Patterns and Related Gene Expression Levels in Red Pears.

Differences in coloration exist among red pear cultivars. Here, we selected six red pear cultivars with different genetic backgrounds to elucidate the characteristics of fruit pigmentation. We detected anthocyanin contents and the expression levels of anthocyanin synthesis-related genes in these cultivars at different stages of fruit development. The anthocyanin contents of all six cultivars showed a rise-drop tendency. Principal component and hierarchical cluster analyses were used to distinguish the types of cultivars and the genes crucial to each anthocyanin accumulation pattern. The six cultivars were divided into three groups. Red Zaosu were clustered into one group, Red Sichou and Starkrimson into another group, and Palacer, Red Bartlett, and 5 Hao clustered into a third group. The expression levels of F3H, UFGT2, MYB10, and bHLH3 were similar among the differential coloration patterns of the six cultivars, suggesting a critical and coordinated mechanism for anthocyanin synthesis. Anthocyanin transporters (GST) and light-responsive genes, such as COP1, PIF3.1, and PIF3.2 played limited roles in the regulation of anthocyanin accumulation. This study provides novel insights into the regulation of anthocyanins synthesis and accumulation in red pears.

Melatonin Inhibits Ethylene Synthesis via Nitric Oxide Regulation To Delay Postharvest Senescence in Pears.

Understanding ripening and senescence processes in postharvest stored fruit is key to the identification and implementation of effective treatment methods. Here, we explored the effects of exogenous applications of melatonin (MT) and nitric oxide (NO) on ripening and softening processes in three cultivars of European pear ( Pyrus communis L.). The results showed that MT and NO played important roles in the two processes: they decreased the rate of upregulation of PcCel and PcPG, inhibited expression of ethylene synthetase genes ( PcACS and PcACO), and reduced rates of respiration and ethylene production. MT increased activity of NO synthase through upregulation of expression of PcNOS that subsequently led to an increase in NO content. However, when NO synthesis was inhibited, the delaying effect of MT on fruit senescence was almost eliminated. These findings indicate that MT acted on the upstream process of NO synthesis that then delayed senescence in pear fruit.

PbCOP1.1 Contributes to the Negative Regulation of Anthocyanin Biosynthesis in Pear.

The synthesis of anthocyanin in pear (Pyrus bretschneideri) fruit is regulated by light. However, little is known about the molecular mechanisms of pear fruit coloring mediated by upstream light-signaling regulators. Here, the photoresponse factors CONSTITUTIVE PHOTOMORPHOGENIC (COP) 1.1 and 1.2 were cloned from 'Red Zaosu' peel to study their functions in pear fruit coloring. The overexpression vectors pBI121-PbCOP1.1 and pBI121-PbCOP1.2 were constructed to analyze their effects on anthocyanin synthesis in pear fruit. A protein sequence alignment and phylogenetic tree analysis revealed that PbCOP1 proteins are highly homologous with those of other species. An analysis of tissue differential expression showed that the greatest expression levels of PbCOP1s occurred in the leaves. Their expression levels increased in the leaves during development, when the leaves changed from red to green. The overexpression of PbCOP1s in the peel resulted in reduced anthocyanin synthesis at the injection sites. A quantitative PCR analysis of the injection sites showed that PbCOP1.1 significantly inhibited the expression of the anthocyanin synthesis-related genes CHI, DFR, UFGT2, bHLH3, HY5 and GST. Based on the above results, we hypothesize that PbCOP1.1 is an anthocyanin synthetic inhibitory factor of pear coloration.