BackgroundObstructive sleep apnea (OSA) is a sleep disorder characterized as complete or partial upper airflow cessation during sleep. Although it has been widely accepted that OSA is a risk factor for the development of hypertension, the studies focusing on this topic revealed inconsistent results. We aimed to clarify the association between OSA and hypertension, including essential and medication-resistant hypertension.MethodsThe Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed. PubMed and Embase databases were used for searching the relevant studies published up to December 31, 2016. A quantitative approach of meta-analysis was performed to estimate the pooled odds ratio (OR) and 95% confidence interval (CI).ResultsTwenty-six studies with 51 623 participants (28 314 men, 23 309 women; mean age 51.8 years) met inclusion criteria and were included in this study. Among them, six studies showed a significant association between OSA and resistant hypertension (pooled OR = 2.842, 95% CI = 1.703-3.980, P < 0.05). Meanwhile, the combination of 20 original studies on the association of OSA with essential hypertension also presented significant results with the pooled ORs of 1.184 (95% CI = 1.093-1.274, P < 0.05) for mild OSA, 1.316 (95% CI = 1.197-1.433, P < 0.05) for moderate OSA and 1.561 (95% CI = 1.287-1.835, P < 0.05) for severe OSA.ConclusionsOur findings indicated that OSA is related to an increased risk of resistant hypertension. Mild, moderate and severe OSA are associated essential hypertension, as well a dose-response manner relationship is manifested. The associations are relatively stronger among Caucasians and male OSA patients.

Melatonin acts as a crucial signaling molecule with multiple physiological functions in plant response to abiotic and biotic stresses. However, the impact and regulatory mechanism of melatonin on attenuating tomato fruit fungal decay are unclear. In this study, we investigated the potential roles of melatonin in modulating fruit resistance to Botrytis cinerea and explored related physiological and molecular mechanisms. The results revealed that disease resistance was strongly enhanced by melatonin treatment, and 50 μM was confirmed as the best concentration. Melatonin treatment increased the activities of defense-related enzymes and decreased hydrogen peroxide (H2O2) content with enhanced antioxidant enzyme activities. Moreover, we found that melatonin treatment increased methyl jasmonate (MeJA) content; up-regulated the expressions of SlLoxD, SlAOC, and SlPI II; and reduced the expressions of SlMYC2 and SlJAZ1. We postulated that melatonin played a positive role in tomato fruit resistance to Botrytis cinerea through regulating H2O2 level and JA signaling pathway.

BackgroundNPR1, nonexpressor of pathogenesis-related gene 1, is a master regulator involved in plant defense response to pathogens, and its regulatory mechanism in the defense pathway has been relatively clear. However, information about the function of NPR1 in plant response to abiotic stress is still limited. Tomato is the fourth most economically crop worldwide and also one of the best-characterized model plants employed in genetic studies. Because of the lack of a stable tomato NPR1 (SlNPR1) mutant, little is known about the function of SlNPR1 in tomato response to biotic and abiotic stresses.ResultsHere we isolated SlNPR1 from tomato ‘Ailsa Craig’ and generated slnpr1 mutants using the CRISPR/Cas9 system. Analysis of the cis-acting elements indicated that SlNPR1 might be involved in tomato plant response to drought stress. Expression pattern analysis showed that SlNPR1 was expressed in all plant tissues, and it was strongly induced by drought stress. Thus, we investigated the function of SlNPR1 in tomato-plant drought tolerance. Results showed that slnpr1 mutants exhibited reduced drought tolerance with increased stomatal aperture, higher electrolytic leakage, malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels, and lower activity levels of antioxidant enzymes, compared to wild type (WT) plants. The reduced drought tolerance of slnpr1 mutants was further reflected by the down-regulated expression of drought related key genes, including SlGST, SlDHN, and SlDREB.ConclusionsCollectively, the data suggest that SlNPR1 is involved in regulating tomato plant drought response. These results aid in further understanding the molecular basis underlying SlNPR1 mediation of tomato drought sensitivity.Electronic supplementary materialThe online version of this article (10.1186/s12870-018-1627-4) contains supplementary material, which is available to authorized users.

Background High temperature is a major environmental stress that limits plant growth and agriculture productivity. Mitogen-activated protein kinases (MAPKs) are highly conserved serine and threonine protein kinases that participate in response to diverse environmental stresses in plants. A total of 16 putative SlMAPK genes are identified in tomato, and SlMAPK3 is one of the most extensively studied SlMAPKs . However, the role of SlMAPK3 in response to heat stress is not clearly understood in tomato plants. In this study, we performed functional analysis of SlMAPK3 for its possible role in response to heat stress. Results qRT-PCR analyses revealed that SlMAPK3 relative expression was depressed by heat stress. Here, wild-type (WT) tomato plants and CRISPR/Cas9-mediated slmapk3 mutant lines (L8 and L13) were used to investigate the function of SlMAPK3 in response to heat stress. Compared with WT plants, slmapk3 mutants exhibited less severe wilting and less membrane damage, showed lower reactive oxygen species (ROS) contents, and presented higher both activities and transcript levels of antioxidant enzymes, as well as elevated expressions of genes encoding heat stress transcription factors ( HSFs ) and heat shock proteins ( HSPs ). Conclusions CRISPR/Cas9-mediated slmapk3 mutants exhibited more tolerance to heat stress than WT plants, suggesting that SlMAPK3 was a negative regulator of thermotolerance. Moreover, antioxidant enzymes and HSPs / HSFs genes expression were involved in SlMAPK3 -mediated heat stress response in tomato plants. Electronic supplementary material The online version of this article (10.1186/s12870-019-1939-z) contains supplementary material, which is available to authorized users.

Background: Stratification by eosinophil and neutrophil counts increases our understanding of asthma and helps target therapy, but there is room for improvement in our accuracy in prediction of treatment responses and a need for better understanding of the underlying mechanisms. Objective: We sought to identify molecular subphenotypes of asthma defined by proteomic signatures for improved stratification. Methods: Unbiased label-free quantitative mass spectrometry and topological data analysis were used to analyze the proteomes of sputum supernatants from 246 participants (206 asthmatic patients) as a novel means of asthma stratification. Microarray analysis of sputum cells provided transcriptomics data additionally to inform on underlying mechanisms. Results: Analysis of the sputum proteome resulted in 10 clusters (ie, proteotypes) based on similarity in proteomic features, representing discrete molecular subphenotypes of asthma. Overlaying granulocyte counts onto the 10 clusters as metadata further defined 3 of these as highly eosinophilic, 3 as highly neutrophilic, and 2 as highly atopic with relatively low granulocytic inflammation. For each of these 3 phenotypes, logistic regression analysis identified candidate protein biomarkers, and matched transcriptomic data pointed to differentially activated underlying mechanisms.

Methyl jasmonate (MeJA) and ethylene play important roles in mediating defense responses against Botrytis cinerea. Ethylene response factors (ERFs) are the final components of ethylene signal transduction; whether SlERF2 participates in disease resistance against Botrytis cinerea is unclear. The objective of this study was to investigate the role of SlERF2 in MeJA-mediated defense response by using both sense and antisense SlERF2 tomato fruit. Our results showed that both MeJA treatment and pathogen infection upregulated SlERF2 expression level. Overexpression of SlERF2 enhanced tomato fruit resistance against Botrytis cinerea. MeJA treatment increased ethylene production, promoted the activities of chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase, and peroxidase, and elevated pathogenesis-related protein content and total phenolic content. Moreover, the effects of MeJA on disease response were reinforced in sense SlERF2 tomato fruit, while they were weakened in antisense SlERF2 tomato fruit. These results indicated that SlERF2 was involved in MeJA-mediated disease resistance against Botrytis cinerea in tomato fruit.

Mitogen-activated protein kinases (MAPKs) play an important role in defense responses to biotic and abiotic stresses. In order to investigate the role of SlMAPK3 in tomato plant resistance to Botrytis cinerea, two lines of slmapk3 mutants and wild-type (WT) tomato plants were used. The results showed that slmapk3 mutants were more susceptible to B. cinerea and that knockout of SlMAPK3 reduced the activities of defense enzymes and enhanced the accumulation of reactive oxygen species (ROS). Furthermore, we detected the expressions of salicylic acid (SA) and jasmonic acid (JA) signaling-related genes and found that knockout of SlMAPK3 enhanced the expressions of SlPR1, SlPAD4 and SlEDS1, whereas reduced the expressions of SlLoxC, SlPI I and SlPI II and enhanced the expressions of SlJAZ1 and SlMYC2. We postulate that SlMAPK3 plays a positive role in tomato plant resistance to B. cinerea through regulating ROS accumulation and SA and JA defense signaling pathways.

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