Prepubertal exposure to polycyclic aromatic hydrocarbons are associated with early pubertal development onset in boys: A longitudinal study.

OBJECTIVE: To investigate the effects of polycyclic aromatic hydrocarbons(PAHs) on puberty in boys. METHODS: 695 subjects were selected from four primary schools in Chongqing, China. 675 urine samples from these boys were collected four PAH metabolites: 1-hydroxypyrene, 2-hydroxynaphthoic, 2-hydroxyfluorene, and 9-hydroxyphenanthrene. Pubertal development of 695 boys was assessed at follow-up visits starting in December 2015 and occurring every six months thereafter until now, data used in this article ending in June 2021. A total of 12 follow-up visits were performed. Cox proportional hazards regression models were used to analyze the relationship between PAH metabolite concentrations and indicators of pubertal timing. RESULTS: The mean age at puberty onset of testicular volume, facial hair, pubic hair, first ejaculation, and axillary hair in boys was 11.66, 12.43, 12.51, 12.72 and 13.70 years, respectively. Cox proportional hazards regression models showed that boys with moderate level of 1-OHPyr exposure was associated with earlier testicular development (hazard ratio [HR] = 1.276, 95% confidence interval [CI]: 1.006-1.619), with moderate level of 2-OHNap were at higher risk of early testicular development (HR = 1.273, 95% CI: 1.002-1.617) and early axillary hair development (HR = 1.355, 95% CI: 1.040-1.764), with moderate level of 2-OHFlu was associated with earlier pubic hair development (HR = 1.256, 95% CI: 1.001-1.577), with high level of 9-OHPhe were at higher risk of early fisrt ejaculation (HR = 1.333, 95% CI: 1.005-1.767) and early facial hair development (HR = 1.393, 95% CI: 1.059-1.831). CONCLUSION: Prepubertal exposure to PAHs may be associated with earlier pubertal development in boys.

Differential game analysis of joint emission reduction decisions under mixed carbon policies and CEA.

To understand joint emission reduction (JER) of upstream and downstream firms under a low-carbon operational environment, this study incorporates green technology, remanufacturing, low-carbon promotion, consumer environmental awareness (CEA), and mixed carbon policies (carbon tax + cap-and-trade) into a dynamic framework to investigate JER decisions of the upstream manufacturer and the downstream retailer. Applying the differential game theory, we consider low-carbon goodwill as the state variable and explore members' optimal decisions in four cases, namely, idealized case, noncooperative case, unilateral cost-sharing contract (UCSC) case, and bilateral cost-sharing contract (BCSC) case. Our results show that the noncooperative case leads to a loss of efficiency in joint emission reduction. Although the BCSC is more advantageous than the UCSC in improving the efficiency of JER, a profit redistribution mechanism needs to be included, and the profit distribution ratio should be controlled within a certain interval. Only in this situation do both parties prefer the BCSC. Additionally, the impact of mixed carbon policies and CEA on JER decisions, low-carbon goodwill, profits, and coordination are fully discussed, and it is found that in the face of stricter mixed carbon policies, the downstream retailer plays a moderating role only in cooperative cases. Several practical implications are concluded for JER, contract design, CEA, and carbon policies. Governments and firms can benefit from our research by gaining a deeper understanding of JER.

Pan-Genomic Analysis Identifies the Chinese Strain as a New Subspecies of Xanthomonas fragariae.

Xanthomonas fragariae is classified as a quarantine pathogen by the European and Mediterranean Plant Protection Organization. It commonly induces typical angular leaf spot (ALS) symptoms in strawberry leaves. X. fragariae strains from China (YL19, SHAQP01, and YLX21) exhibit ALS symptoms in leaves and more severe symptoms of dry cavity rot in strawberry crowns. Conversely, strains from other countries do not cause severe dry cavity rot symptoms in strawberries. After employing multilocus sequence analysis (MLSA), average nucleotide identity (ANI), and amino acid identity (AAI), we determined that Chinese strains of X. fragariae are genetically distinct from other strains and can be considered a new subspecies. Subsequent analysis of 63 X. fragariae genomes published at NCBI using IPGA and EDGAR3.0 revealed the pan-genomic profile, with 1,680 shared genes present in all 63 strains, including 71 virulence-related genes. Additionally, we identified 123 genes exclusive to all the Chinese strains, encompassing 12 virulence-related genes. The qRT-PCR analysis demonstrated that the expression of XopD, XopG1, CE8, GT2, and GH121 out of 12 virulence-related genes of Chinese strains (YL19) exhibited a constant increase in the early stages (6, 24, 54, and 96 hours postinoculation [hpi]) of strawberry leaf infected by YL19. So, the presence of XopD, XopG1, CE8, GT2, and GH121 in Chinese strains may play important roles in the early infection process of Chinese strains. These findings offer novel insights into comprehending the population structure and variation in the pathogenic capacity of X. fragariae.

Emotional and Behavioral Changes in Preschool Firstborn Children During Transition to Siblinghood: A Mixed Methods Study.

Purpose: To help firstborn children in families expecting a second child navigate the role transition more smoothly, we investigated the emotional and behavioral changes of firstborn children during the transition to siblinghood (TTS) and the factors that contribute to these changes. Patients and Methods: From March to December 2019, a total of 97 firstborn children (Mage=3.00± 0.97, and female = 51) were included in the study through a questionnaire survey of their mothers, and two follow-up visits were conducted in Chongqing, China. Individual in-depth interviews were conducted with 14 mothers. Results: Both quantitative and qualitative results suggest that emotional and behavioral problems of firstborn children tend to increase during TTS, particularly in issues such as anxiety/depression, somatic complaints, withdrawal, sleep problems, attention problems, and aggressive behavior, as well as internalization problems, externalization problems and total problems in the quantitative study (P<0.05). A poor father-child relationship may increase emotional and behavioral problems in firstborn children (P=0.05). Further qualitative analysis found that younger age and outgoing personality of the firstborn child may improve the emotional and behavioral problems. Conclusion: The firstborn children did have more emotional and behavioral problems during TTS. But these problems can be regulated by family factors and their own characteristics.

Pre-transjugular-intrahepatic-portosystemic-shunt measurement of hepatic venous pressure gradient and its clinical application: A comparison study.

BACKGROUND: It is controversial whether transjugular intrahepatic portosystemic shunt (TIPS) placement can improve long-term survival. AIM: To assess whether TIPS placement improves survival in patients with hepatic-venous-pressure-gradient (HVPG) ≥ 16 mmHg, based on HVPG-related risk stratification. METHODS: Consecutive variceal bleeding patients treated with endoscopic therapy + nonselective ß-blockers (NSBBs) or covered TIPS placement were retrospectively enrolled between January 2013 and December 2019. HVPG measurements were performed before therapy. The primary outcome was transplant-free survival; secondary endpoints were rebleeding and overt hepatic encephalopathy (OHE). RESULTS: A total of 184 patients were analyzed (mean age, 55.27 years ± 13.86, 107 males; 102 in the EVL+NSBB group, 82 in the covered TIPS group). Based on the HVPG-guided risk stratification, 70 patients had HVPG < 16 mmHg, and 114 patients had HVPG ≥ 16 mmHg. The median follow-up time of the cohort was 49.5 mo. There was no significant difference in transplant-free survival between the two treatment groups overall (hazard ratio [HR], 0.61; 95% confidence interval [CI]: 0.35-1.05; P = 0.07). In the high-HVPG tier, transplant-free survival was higher in the TIPS group (HR, 0.44; 95%CI: 0.23-0.85; P = 0.004). In the low-HVPG tier, transplant-free survival after the two treatments was similar (HR, 0.86; 95%CI: 0.33-0.23; P = 0.74). Covered TIPS placement decreased the rate of rebleeding independent of the HVPG tier (P < 0.001). The difference in OHE between the two groups was not statistically significant (P = 0.09; P = 0.48). CONCLUSION: TIPS placement can effectively improve transplant-free survival when the HVPG is greater than 16 mmHg.

Systemic Colonization of Xanthomonas fragariae Strain YL19 Causing Dry Cavity Rot of Strawberry Crown Tissue in China.

Xanthomonas fragariae usually causes angular leaf spot (ALS) of strawberry, a serious bacterial disease in many strawberry-producing regions worldwide. Recently, a new strain of X. fragariae (YL19) was isolated from strawberry in China and has been shown to cause dry cavity rot in strawberry crown. In this study, we constructed a green fluorescent protein (GFP)-labeled Xf YL19 (YL19-GFP) to visualize the infection process and pathogen colonization in strawberries. Foliar inoculation of YL19-GFP resulted in the pathogen migrating from the leaves to the crown, whereas dip inoculation of wounded crowns or roots resulted in the migration of bacteria from the crowns or roots to the leaves. These two invasion types both resulted in the systematic spread of YL19-GFP, but inoculation of a wounded crown was more harmful to the strawberry plant than foliar inoculation. Results increased our understanding of the systemic invasion of X. fragariae, and the resultant crown cavity caused by Xf YL19.

Co-Development and Bidirectional Associations Between Psychological Stress and Obesity in School-Aged Children: A Longitudinal Study in China.

OBJECTIVE: Psychological stress (PS) has always been a hot topic for researchers to investigate the potential determinants of childhood overweight/obesity. Up to now, cohort studies investigating the relationship between PS and childhood obesity have used different ways to assess PS, different indicators to measure obesity, and different analysis methods, and the results were also inconsistent. METHODS: Data were obtained from the second to eighth follow-up of an ongoing cohort of school-aged children in Chongqing, China (June 2015-June 2018), with seven waves (W1-W7, NW1 = 1419). The latent growth curve model was used to estimate the co-developmental trends between PS and obesity (body mass index [BMI], waist-to-height ratio [WHtR]). Random intercept cross-lagged panel models were constructed to examine their longitudinal bidirectional associations. RESULTS: The changes in PS and obesity (BMI, WHtR) were co-developing ( rBMI = -1.105, p = .003; rWHtR = -0.991, p = .004). Longitudinal models showed significant negative correlations between PS and obesity at the between-person level ( rBMI = -4.993; rWHtR = -1.591). BMI at W3 could negatively predict PS 6 months later ( ß = -1.508, p = .027), and WHtR at W1 could negatively predict PS at W3 ( ß = -2.809, p = .014). Different aspects of PS had different associations with obesity. Notably, there was a significant reciprocal relationship between peer interaction PS and obesity. CONCLUSIONS: Different aspects of PS were differentially associated with obesity. Notably, there may be a clear reciprocal relationship between peer interaction PS and obesity. These findings provide new directions for protecting children's mental health to prevent or control childhood overweight/obesity.

High-performance phononic crystal sensing structure for acetone solution concentration sensing.

A two-dimensional phononic crystal sensor model with high-quality factor and excellent sensitivity for sensing acetone solutions and operating at 25-45 kHz is proposed. The model for filling solution cavities is based on reference designs of quasi-crystal and gradient cavity structures. The transmission spectrum of sensor is simulated by the finite element method. High-quality factor of 45,793.06 and sensitivity of 80,166.67 Hz are obtained for the acetone concentration with 1-9.1%, and quality factor of 61,438.09 and sensitivity of 24,400.00 Hz are obtained for the acetone concentration range of 10-100%, which indicated the sensor could still achieve high sensitivity and quality factor at operating frequencies from 25 to 45 kHz. To verify the application of the sensor to sensing other solutions, the sensitivity for sound velocity and density is calculated as 24.61 m-1 and 0.7764 m3/(kg × s), respectively. It indicates the sensor is sensitive to acoustic impedance changes of the solution and equally suitable for sensing other solutions. The simulation results reveal the phononic crystal sensor possessed high-performance in composition capture in pharmaceutical production and petrochemical industry, which can provide theoretical reference for the design of new biochemical sensors for reliable detection of solution concentration.

The influence of the trajectory of obesity indicators on the age of pubertal onset and pubertal tempo in girls: A longitudinal study in Chongqing, China.

Objective: This study aims to explore the influence of the trajectory of obesity indicators on the onset age of different pubertal development characteristics and pubertal tempo among girls. Methods: Our longitudinal cohort study recruited 734 girls at baseline in May 2014 from a district of Chongqing and followed them at 6-month intervals. Data were available from baseline to the 14th follow-up with a full record of height, weight, waist circumference (WC), breast development, pubic hair, and armpit hair development, as well as the age of menarche. The Group-Based Trajectory Model (GBTM) was fitted for the optimum trajectory of the body mass index (BMI), WC, and waist-to-height ratio (WHtR) of girls before the pubertal onset and menarche. The ANOVA and multiple linear regression model were conducted to analyze the influence of the trajectory of obesity indicators on the onset age of different pubertal development characteristics and pubertal tempo in girls. Results: Compared with the healthy (gradual BMI increase) group before pubertal onset, the overweight (persistent BMI increase) group has an earlier onset age of breast development (B: -0.331, 95%CI: -0.515, -0.147) and pubic hair development (B: -0.341, 95%CI: -0.546, -0.136). The B2-B5 development time was shorter in girls in the overweight (persistent BMI increase) group (B: -0.568, 95%CI: -0.831, -0.305) and the obese (rapid BMI increase) group (B: -0.328, 95%CI: -0.524, -0.132). The age of menarche was earlier, and the B2-B5 development time was shorter in girls in the overweight (persistent BMI increase) group than in girls in the healthy (gradual BMI increase) group before menarche (B: -0.276, 95%CI: -0.406, -0.146; B: -0.263, 95%CI: -0.403, -0.123). Girls with high WC (rapid WC increase) before menarche had an earlier age of menarche than normal WC (gradual WC increase) (B: -0.154, 95%CI: -0.301, -0.006), and the B2-B5 development time was shorter in girls in the overweight (gradual WHtR increase) group than in girls in the healthy (persistent WHtR increase) (B: -0.278, 95%CI: -0.529, -0.027) group. Conclusion: Among girls, overweight and obesity (BMI scale) before pubertal onset can not only influence pubertal onset age but also accelerate B2-B5 pubertal tempo. Overweight (BMI scale) and high WC before menarche also have an impact on the age of menarche. Overweight (WHtR scale) before menarche is significantly associated with B2-B5 pubertal tempo.

Polycyclic aromatic hydrocarbons are associated with later puberty in girls: A longitudinal study.

The objective of this study is to explore associations between PAH exposures and puberty timing in girls. Beginning in May 2014, 734 girls age 7.2-11.8 years in Chongqing, China, were enrolled in a prospective cohort study. They were followed up every 6 months from enrollment through June 2021, at which point participants were ages 13.6-18.3 years. Metabolite concentrations of four PAHs (1-hydroxypyrene [1-OHPyr], 2-hydroxynaphthalene [2-OHNap], 2-hydroxyfluorine [2-OHFlu], and 9-hydroxyphenanthrene [9-OHPhe]) were measured in urine samples at baseline. At each follow up visit, the Tanner's Sexual Maturity Rating scale was administered. Cox proportional hazards models were used to estimate associations between four urinary PAH metabolite concentrations and four markers of puberty: menarche, breast development, pubic hair development, and axillary hair development. Geometric mean concentrations of 1-OHPyr, 2-OHNap, 2-OHFlu and 9-OHPhe in urine were 0.47 µg/L, 3.31 µg/L, 1.49 µg/L, 3.75 µg/L, respectively. There were statistically significant associations between several urinary PAH metabolite concentrations and puberty outcomes. PAH metabolite concentrations were grouped as Low (<25th percentile, referent group), Moderate (25th-75th percentile) or High (>75th). Girls with moderate levels of 1-OHPyr were at higher risk of delayed pubic hair development (hazard ratio [HR]: 0.82, 95 % confidence interval [CI]: 0.68-0.99). Delayed breast development (HR: 0.77, 95 % CI: 0.60-0.99) and pubic hair development (HR: 0.76, 95 % CI: 0.60-0.95) were associated with high 2-OHNap. High c 2-OHFlu was associated with delayed pubic hair development (HR: 0.77, 95 % CI: 0.61-0.96). Delayed breast (HR: 0.79, 95 % CI: 0.64-0.97), pubic hair (HR: 0.79, 95 % CI: 0.65-0.96) and axillary hair development (HR: 0.80, 95 % CI: 0.65-0.99) was associated with moderate 9-OHPhe. In conclusion, PAH exposure may delay puberty onset in girls.

Emotional and Behavioral Changes and Related Factors of Firstborn School-Aged Compared to Same Age Only Children.

Objective: To compare the emotional and behavioral characteristics of firstborn children during the pregnancy of a second child and only children of school-age in urban districts of Chongqing, China, and to explore the influencing factors of emotional and behavioral problems. Methods: We recruited mothers of firstborn children and only children from two hospitals and one primary school using purposive sampling. Questionnaires and the Parental Child Behavior Checklist (CBCL) were used to collect basic information, family socioeconomic status, family atmosphere and emotional and behavioral characteristics of their children in the survey. Results: The sample consisted of 1,155 children, including 477 firstborn children and 678 only children. The average scores of internalizing (4.47), externalizing (6.05), total problems (22.04), and six emotional and behavioral of firstborn children were significantly lower than those of only children (p < 0.05). When adjusted for children's demographic, socioeconomic and family relationship covariates, the scores of firstborn children internalizing problems (ß = -1.423, p = 0.000), externalizing problems (ß = -0.661, p = 0.048), and total problems (ß = -4.387, p = 0.000) were also significantly lower than those of only children. All children with more difficult parenting and development temperament, greater family economic pressure, poorer relationships between mother and child, less harmonious family atmosphere and father's permissive parenting style had more internalizing problems, externalizing problems and total problems (p < 0.05). Boys had more externalizing problems (ß = 1.939, 95% CI = 1.380-2.497) and total problems (ß = 4.908, 95% CI = 3.045-6.772) than girls. Conclusion: Firstborn children had fewer emotional and behavioral problems than their counterparts who were only children. This research helps to understand the social impact of the implementation of the two-child policy in multiple dimensions.

Implementation of environmental regulation strategies for nitrogen pollution in river basins: a stakeholder game perspective.

With the rapid development of modern agriculture, non-point source nitrogen pollution from higher polluting farms has become one of the main contributions to the eutrophication of the watershed. This paper first constructed a tripartite evolutionary game model concerning local governments, higher polluting farms, and consumers, all of which participate in the reduction of nitrogen pollution in the river basin. Secondly, the evolution process of evolutionary stability strategy (ESS) and the impact of critical parameters on the strategies of the three stakeholders were analyzed through numerical simulation. The results demonstrated that (1) six ESSs of the system are determined, only (1, 0, 1) is regarded as the most ideal ESS: regulation by local governments, higher polluting farms adopting not purchasing emission rights, and consumers purchasing green agricultural products. (2) The regulation strategy of local governments depends on comparing political losses with the sum of emission reduction subsidies and the supervision cost. (3) The marginal abatement costs, the price of nitrogen emission permits, nitrogen use efficiency, and the subsidy standard for unit emission reduction are the main factors that affect the ESS of higher polluting farms. (4) The ESS of consumers is significantly affected by low-nitrogen preference, government subsidies, and nitrogen use efficiency. This study suggests that the government should strengthen the supervision of the watershed environment from the aspects of improving the market mechanism of nitrogen trading, establishing a dynamic monitoring system, and innovating a subsidy mechanism.

A comparison of non-intubated video-assisted thoracic surgery with spontaneous ventilation and intubated video-assisted thoracic surgery: a meta-analysis based on 14 randomized controlled trials.

BACKGROUND: Video-assisted thoracic surgery (VATS) generally involves endotracheal intubation under general anesthesia. However, inevitably, this may cause intubation-related complications and prolong the postoperative recovery process. Gradually, non-intubated video-assisted thoracic surgery (NIVATS) is increasingly being utilized. However, its safety and efficacy remain controversial. METHODS: Randomized controlled trials (RCTs) published up to August 2020 were selected from the Cochrane Library, Web of Science, PubMed, Embase, and ClinicalTrials.gov databases and included in this study according to the inclusion criteria. Two reviewers screened these RCTs and independently extracted the relevant data. After assessing the risk of bias in these RCTs, a meta-analysis was performed using Review Manager 5.3. Pooled data were meta-analyzed using a random-effects model. RESULTS: Meta-analysis data demonstrated that the mean difference (MD) in the length of hospital stay between non-intubated patients and intubated patients was -1.41 days, with a 95% confidence interval (CI) of -2.47 to -0.34 (P=0.01). The visual analogue scale (VAS) score between the two groups showed a MD of -0.34 (95% CI: -0.58 to -0.10; P=0.006). Patients who underwent NIVATS presented with lower rates of overall complications [odds ratio (OR) 0.41; 95% CI: 0.25 to 0.67; P=0.0004], air leak (OR 0.45; 95% CI: 0.24 to 0.87; P=0.02), pharyngeal discomfort (OR 0.08; 95% CI: 0.04 to 0.17; P<0.00001), hoarseness (OR 0.06; 95% CI: 0.02 to 0.21; P<0.00001), and gastrointestinal reactions (OR 0.23; 95% CI: 0.10 to 0.53; P=0.0005) compared to intubated patients. The anesthesia satisfaction scores in the NIVATS group were significantly higher than those of the VATS group (MD 0.50; 95% CI: 0.12 to 0.88; P=0.009). However, there were no statistically significant differences in the length of operation time (MD 0.90 hours; 95% CI: -0.23 to 2.03; P=0.12) and surgical field satisfaction (1 point) (OR 0.73; 95% CI: 0.34 to 1.59; P=0.43) between the two groups. CONCLUSIONS: NIVATS is a safe and feasible form of intervention that can reduce the postoperative pain and complications of various systems and shorten hospital stay duration without prolonging the operation time.

Tunable characteristics of low-frequency bandgaps in two-dimensional multivibrator phononic crystal plates under prestrain.

In view of the influence of variability of low-frequency noise frequency on noise prevention in real life, we present a novel two-dimensional tunable phononic crystal plate which is consisted of lead columns deposited in a silicone rubber plate with periodic holes and calculate its bandgap characteristics by finite element method. The low-frequency bandgap mechanism of the designed model is discussed simultaneously. Accordingly, the influence of geometric parameters of the phononic crystal plate on the bandgap characteristics is analyzed and the bandgap adjustability under prestretch strain is further studied. Results show that the new designed phononic crystal plate has lower bandgap starting frequency and wider bandwidth than the traditional single-sided structure, which is due to the coupling between the resonance mode of the scatterer and the long traveling wave in the matrix with the introduction of periodic holes. Applying prestretch strain to the matrix can realize active realtime control of low-frequency bandgap under slight deformation and broaden the low-frequency bandgap, which can be explained as the multiple bands tend to be flattened due to the localization degree of unit cell vibration increases with the rise of prestrain. The presented structure improves the realtime adjustability of sound isolation and vibration reduction frequency for phononic crystal in complex acoustic vibration environments.

Regular Open-Skill Exercise Generally Enhances Attentional Resources Related to Perceptual Processing in Young Males.

This study aimed to examine whether the regular open-skill exercise led to a selective improvement or a general improvement on cognitive function in healthy young males. Besides, we also intend to expand previous studies by looking into the temporal dynamics of early information processes and cognitive processes through appraising the extensive temporal series of stimulus-locked ERP components. Sixty healthy young males were classified into two groups: those who regularly participated in the open-skill exercise for at least 2 years (n = 30), and those who exercised rarely. The participants conducted the Stroop task with event-related brain potential (ERP) recorded. The results indicated that compared with the rare exercise group, the open-skill exercise group led to a selective improvement for accuracy under the incongruent condition. And the open-skill exercise group also led to a selective improvement for response time under the incongruent condition. Moreover, the open-skill exercise group yielded larger P200 amplitudes under both the congruent and incongruent conditions compared with the rare exercise group. The findings suggest that the regular open-skill exercise may promote executive function by an increase in the allocation of attentional resources related to perceptual processing and greater interference control during cognitively demanding tasks in healthy young males.

A small heat shock protein CaHsp25.9 positively regulates heat, salt, and drought stress tolerance in pepper (Capsicum annuum L.).

Extreme environmental conditions seriously affect crop growth and development, resulting in a decrease in crop yield and quality. However, small heat shock proteins (Hsp20s) play an important role in helping plants to avoid these negative impacts. In this study, we identified the expression pattern of the CaHsp25.9 gene in a thermo-tolerance pepper line R9 and thermo-sensitive line B6. The transcription of CaHsp25.9 was strongly induced by heat stress in both R9 and B6. The expression of CaHsp25.9 was induced by salt and drought stress in R9. Additionally, the CaHsp25.9 protein was localized in the cell membrane and cytoplasm. When silencing the CaHsp25.9 gene in the R9 line, the accumulation of malonaldehyde (MDA), relative electrolytic leakage, hydrogen peroxide, superoxide anion were increased, while total chlorophyll decreased under heat, salt, and drought stress. Over-expression of CaHsp25.9 in Arabidopsis resulted in decreased MDA, while proline, superoxide dismutase activity, germination, and root length increased under heat, salt, and drought stress. However, peroxidase activity was higher in drought stress but lower in heat and salt stress in transgenic Arabidopsis compared to the wild type (WT). Furthermore, the transcription of stress related genes was more highly induced in transgenic lines than WT. Our results indicated that CaHsp25.9 confers heat, salt, and drought stress tolerance to plants by reducing the accumulation of reactive oxygen species, enhancing the activity of antioxidant enzymes, and regulating the expression of stress-related genes. Therefore, these results may provide insight into plant adaption mechanisms developed in variable environments.

Identification of TRAF6 as a ubiquitin ligase engaged in the ubiquitination of SopB, a virulence effector protein secreted by Salmonella typhimurium.

The phosphoinositide phosphatase SopB is one of the effectors injected by Salmonella typhimurium (S.typhimurium) that diversifies its function through a ubiquitin-dependent differential localization. However, it is unclear which E3 ubiquitin ligase is responsible for ubiquitination of SopB. Based on the E1-E2-E3 trio of enzymes responsible for the ubiquitin activation and translocation to substrate proteins, we constructed an in vitro assay of SopB ubiquitination. Using this assay, we purified an E3 ubiquitin ligase, TRAF6, from the Henle-407 S100 extraction that may be responsible for the ubiquitination of SopB. To investigate the functional correlation of TRAF6, we showed that recombinant TRAF6 specifically ubiquitinates SopB in a dose-dependent manner in vitro. Upon infection, the ubiquitination of SopB was absolutely blocked by TRAF6 deletion, as shown in Traf6(-/-) mouse embryonic fibroblasts (MEFs) compared with Traf6(+/+) MEFs. However, the ectopic expression of TRAF6 in Traf6(-/-) MEFs rescued the two species of ubiquitin-conjugated SopB, which strengthens the role of TRAF6 in SopB ubiquitination. The analysis of E2 revealed that UbcH5c and not other E2 conjugating enzymes are required for TRAF6-mediated SopB ubiquitination both in vitro and in vivo. In summary, these results suggest the relevance of UbcH5c/TRAF6 in SopB during S.typhimurium infection and thereby imply that S.typhimurium has evolved a mechanism of utilizing the host's E3 ubiquitin ligase to modify and modulate the function of its effector protein in order to ensure pathogen and host cell survival.