[Soil Microbial Community Structure and Functional Diversity Character of Abandoned Farmland in Minqin Oasis].

To clarify the impact of the structure and function of soil microbial communities in the stage of abandoned farmland, three different stages of land abandoned in desert oasis areas were selected as the research objects. We used metagenomic sequencing technology to research soil microbial community structure and functional diversity characteristics of different stages of abandoned farmland. The results showed that there were significant differences in the relative abundance of the dominant phyla Actinobacteria, Proteobacteria, and Gemmatimonadetes in the soil of the three stages of returning farmland. Compared with that in the early stage of abandoned farmland, the later stage of abandoned farmland restoration increased the gene proportion involved in Quorum sensing, porphyrin and chlorophyll metabolism, pantothenate and CoA biosynthesis, and styrene degradation, and there was a significant difference in relative abundance (P<0.05), which indicated that different stages of abandoned farmland had changed the functional potential of the nutrient cycle and energy metabolism in soil microbial communities. The RDA results showed that EC, AK, and TN had a significant impact on the functional composition of soil microbes, and soil EC had the greatest impact on microbial functional composition. The results showed that different stages of abandoned farmland had a significant impact on the soil microbial community structure and functional composition. In the ecological restoration of abandoned farmland in Minqin Oasis, the sensitivity of microbial community structure and functional composition to soil restoration at different stages should be considered using comprehensive relevant indicators.

Lower circulating irisin levels in type 2 diabetes mellitus patients with chronic complications: A meta-analysis.

Purpose: The aim of this study was to provide evidence of the differences in circulating irisin levels between type 2 diabetes mellitus (T2DM) patients with and without chronic complications. Methods: We performed a meta-analysis to compare circulating irisin levels between different groups. Literature search was conducted in PubMed, Cochrane Library, Embase, WanFang, and China National Knowledge Infrastructure databases from inception through December 2022. Random effects model and standard mean difference (SMD) was used to calculate the pooled outcomes with 95 % confidence intervals (CIs). Results: Forty-two studies that matched the inclusion criteria were analyzed. Circulating irisin levels were significantly lower in T2DM patients with chronic complications than those in T2DM patients without chronic complications (SMD: -1.43; 95 % CI: -1.76 to -1.09; p < 0.00001) and healthy control group (SMD: -2.40; 95 % CI: -3.02 to -1.77; p < 0.00001). Moreover, irisin levels further decrease with the aggravation of complications in T2DM patients with diabetic nephropathy or diabetic retinopathy. Conclusion: Compared with T2DM patients without chronic complications, T2DM patients with chronic complications had lower circulating irisin levels. In addition, irisin levels were negatively correlated with the severity of chronic complications.

Design and rationale of the ATTRACTIVE trial: a randomised trial of intrAThrombus Thrombolysis versus aspiRAtion thrombeCTomy during prImary percutaneous coronary interVEntion in ST-segment elevation myocardial infarction patients with high thrombus burden.

INTRODUCTION: ST-segment elevation myocardial infarction (STEMI) with high thrombus burden is associated with a poor prognosis. Manual aspiration thrombectomy reduces coronary vessel distal embolisation, improves microvascular perfusion and reduces cardiovascular deaths, but it promotes more strokes and transient ischaemic attacks in the subgroup with high thrombus burden. Intrathrombus thrombolysis (ie, the local delivery of thrombolytics into the coronary thrombus) is a recently proposed treatment approach that theoretically reduces thrombus volume and the risk of microvascular dysfunction. However, the safety and efficacy of intrathrombus thrombolysis lack sufficient clinical evidence. METHODS AND ANALYSIS: The intrAThrombus Thrombolysis versus aspiRAtion thrombeCTomy during prImary percutaneous coronary interVEntion trial is a multicentre, prospective, open-label, randomised controlled trial with the blinded assessment of outcomes. A total of 2500 STEMI patients with high thrombus burden who undergo primary percutaneous coronary intervention will be randomised 1:1 to intrathrombus thrombolysis with a pierced balloon or upfront routine manual aspiration thrombectomy. The primary outcome will be the composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, heart failure readmission, stent thrombosis and target-vessel revascularisation up to 180 days. ETHICS AND DISSEMINATION: The trial was approved by Ethics Committees of China-Japan Friendship Hospital (2022-KY-013) and all other participating study centres. The results of this trial will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05554588.

Predictive value of the stress hyperglycemia ratio in dialysis patients with acute coronary syndrome: insights from a multi-center observational study.

BACKGROUND: Various studies have indicated that stress hyperglycemia ratio (SHR) can reflect true acute hyperglycemic status and is associated with poor outcomes in patients with acute coronary syndrome (ACS). However, data on dialysis patients with ACS are limited. The Global Registry of Acute Coronary Events (GRACE) risk score is a well-validated risk prediction tool for ACS patients, yet it underestimates the risk of major events in patients receiving dialysis. This study aimed to evaluate the association between SHR and adverse cardiovascular events in dialysis patients with ACS and explore the potential incremental prognostic value of incorporating SHR into the GRACE risk score. METHODS: This study enrolled 714 dialysis patients with ACS from January 2015 to June 2021 at 30 tertiary medical centers in China. Patients were stratified into three groups based on the tertiles of SHR. The primary outcome was major adverse cardiovascular events (MACE), and the secondary outcomes were all-cause mortality and cardiovascular mortality. RESULTS: After a median follow-up of 20.9 months, 345 (48.3%) MACE and 280 (39.2%) all-cause mortality occurred, comprising 205 cases of cardiovascular death. When the highest SHR tertile was compared to the second SHR tertile, a significantly increased risk of MACE (adjusted hazard ratio, 1.92; 95% CI, 1.48-2.49), all-cause mortality (adjusted hazard ratio, 2.19; 95% CI, 1.64-2.93), and cardiovascular mortality (adjusted hazard ratio, 2.70; 95% CI, 1.90-3.83) was identified in the multivariable Cox regression model. A similar association was observed in both diabetic and nondiabetic patients. Further restricted cubic spline analysis identified a J-shaped association between the SHR and primary and secondary outcomes, with hazard ratios for MACE and mortality significantly increasing when SHR was > 1.08. Furthermore, adding SHR to the GRACE score led to a significant improvement in its predictive accuracy for MACE and mortality, as measured by the C-statistic, net reclassification improvement, and integrated discrimination improvement, especially for those with diabetes. CONCLUSIONS: In dialysis patients with ACS, SHR was independently associated with increased risks of MACE and mortality. Furthermore, SHR may aid in improving the predictive efficiency of the GRACE score, especially for those with diabetes. These results indicated that SHR might be a valuable tool for risk stratification and management of dialysis patients with ACS.

The triglyceride-glucose index predicts 1-year major adverse cardiovascular events in end-stage renal disease patients with coronary artery disease.

BACKGROUND: The triglyceride-glucose (TyG) index has been suggested as a dependable indicator for predicting major adverse cardiovascular events (MACE) in individuals with cardiovascular conditions. Nevertheless, there is insufficient data on the predictive significance of the TyG index in end-stage renal disease (ESRD) patients with coronary artery disease (CAD). METHODS: This study, conducted at multiple centers in China, included 959 patients diagnosed with dialysis and CAD from January 2015 to June 2021. Based on the TyG index, the participants were categorized into three distinct groups. The study's primary endpoint was the combination of MACE occurring within one year of follow-up, including death from any cause, non-fatal myocardial infarction, and non-fatal stroke. We assessed the association between the TyG index and MACE using Cox proportional hazard models and restricted cubic spline analysis. The TyG index value was evaluated for prediction incrementally using C-statistics, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: The three groups showed notable variations in the risk of MACE (16.3% in tertile 1, 23.5% in tertile 2, and 27.2% in tertile 3; log-rank P = 0.003). Following complete adjustment, patients with the highest TyG index exhibited a notably elevated risk of MACE in comparison to those in the lowest tertile (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.14-2.35, P = 0.007). Likewise, each unit increase in the TyG index correlated with a 1.37-fold higher risk of MACE (HR 1.37, 95% CI 1.13-1.66, P = 0.001). Restricted cubic spline analysis revealed a connection between the TyG index and MACE (P for nonlinearity > 0.05). Furthermore, incorporating the TyG index to the Global Registry of Acute Coronary Events risk score or baseline risk model with fully adjusted factors considerably enhanced the forecast of MACE, as demonstrated by the C-statistic, continuous NRI, and IDI. CONCLUSIONS: The TyG index might serve as a valuable and dependable indicator of MACE risk in individuals with dialysis and CAD, indicating its potential significance in enhancing risk categorization in clinical settings.

Association of triglyceride-glucose index with coronary severity and mortality in patients on dialysis with coronary artery disease.

BACKGROUND: The triglyceride-glucose (TyG) index is validated as a reliable biomarker of insulin resistance and an independent predictor of cardiovascular prognosis. However, the prognostic value of the TyG index in patients on dialysis with coronary artery disease (CAD) remained unexplored. This study aimed to determine the association between the TyG index and CAD severity and mortality in these patients. METHODS: A total of 1061 dialysis patients with CAD were enrolled in this multi-center cohort study from January 2015 to June 2021. The extent and severity of CAD were evaluated using the multivessel disease and Gensini score (GS). Patients were followed up for all-cause death and cardiovascular death. RESULTS: The multivariable logistic regression model indicated that the TyG index was significantly associated with multivessel disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.18-1.94, P = 0.001), and high GS (OR 1.33, 95% CI 1.10-1.61, P = 0.003). After adjusting for baseline risk factors, the hazards of all-cause death and cardiovascular death were 1.23 (95% CI 1.06-1.43, P = 0.007), and 1.33 (95% CI 1.11-1.59, P = 0.002), independent of CAD severity. Restricted cubic spline analysis identified a dose-response association between the TyG index and both CAD severity and mortality (all P for nonlinearity > 0.05). When modeling the TyG index as a categorical variable, these independent associations remained. Subgroup analyses did not substantially modify the results. Furthermore, incorporating the TyG index into the existing risk prediction model improved the predictive accuracy for all-cause death and cardiovascular death, as evaluated by C-statistic, continuous net reclassification improvement, and integrated discrimination improvement. CONCLUSIONS: In patients on dialysis with CAD, the TyG index was significantly associated with more severe CAD as well as mortality. These results highlight the clinical importance of the TyG index for assessing CAD severity and risk stratification in patients on dialysis with CAD.

Dynamic Assessments of Coronary Flow Reserve after Myocardial Ischemia Reperfusion in Mice.

After cardiac ischemia, there is often insufficient myocardial perfusion, even if flow has been successfully and completely restored in an upstream artery. This phenomenon, known as the "no-reflow phenomenon," is attributed to coronary microvascular dysfunction and has been associated with poor clinical outcomes. In clinical practice, a reduction in coronary flow reserve (CFR) is frequently used as an indicator of coronary artery disease. CFR is defined as the ratio of the peak flow velocity induced by pharmacologic or metabolic factors to the resting flow velocity. This protocol focused on assessing the dynamic changes in CFR before and after ischemia-reperfusion (IR) using pulse wave Doppler measurements. In this study, normal mice exhibited the ability to increase the peak velocity of coronary blood flow up to two times higher than the resting values under isoflurane stimulation. However, after ischemia-reperfusion, the CFR at 1 h significantly decreased compared to the pre-operation baseline. Over time, the CFR showed gradual recovery, but it remained below the normal level. Despite the preservation of systolic function, early detection of microvascular dysfunction is crucial, and establishing a practical guide could aid doctors in this task, while also facilitating the study of cardiovascular disease progression over time.

Effects of Metformin on COVID-19 Patients with Type 2 Diabetes: A Retrospective Study.

Purpose: The pandemic of coronavirus disease 2019 (COVID-19) has highlighted the intricate relationship between underlying conditions and death. We designed this study to determine whether metformin therapy for type 2 diabetes mellitus (T2D) is associated with low in-hospital mortality in patients hospitalized for COVID-19. Materials and Methods: This was a retrospective study including patients with COVID-19 and T2D in Wuhan, from February 4th to April 11th, 2020. Patients were divided into two groups according to metformin exposure. The hazard ratio (HR) of COVID-19-related mortality and invasive mechanical ventilation was estimated using Cox regression. Results: There were 571 T2D patients among the 4330 confirmed COVID-19 patients. Of those patients, 241 received metformin therapy. The in-hospital mortality and invasive mechanical ventilation of metformin group was lower than non-metformin group. In the multivariate model, metformin use was linked to a decreased in-hospital mortality and invasive mechanical ventilation when compared with that of the control group (HR: 0.376 [95% CI 0.154-0.922]; P = 0.033). Conclusion: Our study indicated that metformin therapy was associated with decreased death risk in COVID-19 patients with T2D.

Ticagrelor vs. clopidogrel for coronary microvascular dysfunction in patients with STEMI: a meta-analysis of randomized controlled trials.

Purpose: Approximately half of ST-segment elevation myocardial infarction (STEMI) patients who undergo revascularization present with coronary microvascular dysfunction. Dual antiplatelet therapy, consisting of aspirin and a P2Y12 inhibitor (e.g., clopidogrel or ticagrelor), is recommended to reduce rates of cardiovascular events after STEMI. The present study performed a pooled analysis of randomized controlled trials (RCTs) to compare effects of ticagrelor and clopidogrel on coronary microcirculation dysfunction in STEMI patients who underwent the primary percutaneous coronary intervention. Methods: The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for eligible RCTs up to September 2022, with no language restriction. Coronary microcirculation indicators included the corrected thrombolysis in myocardial infarction (TIMI) frame count (cTFC), myocardial blush grade (MBG), TIMI myocardial perfusion grade (TMPG), coronary flow reserve (CFR), and index of microcirculatory resistance (IMR). Results: Seven RCTs that included a total of 957 patients (476 who were treated with ticagrelor and 481 who were treated with clopidogrel) were included. Compared with clopidogrel, ticagrelor better accelerated microcirculation blood flow [cTFC = -2.40, 95% confidence interval (CI): -3.38 to -1.41, p < 0.001] and improved myocardial perfusion [MBG = 3, odds ratio (OR) = 1.99, 95% CI: 1.35 to 2.93, p < 0.001; MBG ≥ 2, OR = 2.57, 95% CI: 1.61 to 4.12, p < 0.001]. Conclusions: Ticagrelor has more benefits for coronary microcirculation than clopidogrel in STEMI patients who undergo the primary percutaneous coronary intervention. However, recommendations for which P2Y12 receptor inhibitor should be used in STEMI patients should be provided according to results of studies that investigate clinical outcomes.

Association between the triglyceride glucose index and in-hospital and 1-year mortality in patients with chronic kidney disease and coronary artery disease in the intensive care unit.

OBJECTIVE: This study aimed to explore the association between the triglyceride glucose index (TyG) and the risk of in-hospital and one-year mortality in patients with chronic kidney disease (CKD) and cardiovascular disease (CAD) admitted to the intensive care unit (ICU). METHODS: The data for the study were taken from the Medical Information Mart for Intensive Care-IV database which contained over 50,000 ICU admissions from 2008 to 2019. The Boruta algorithm was used for feature selection. The study used univariable and multivariable logistic regression analysis, Cox regression analysis, and 3-knotted multivariate restricted cubic spline regression to evaluate the association between the TyG index and mortality risk. RESULTS: After applying inclusion and exclusion criteria, 639 CKD patients with CAD were included in the study with a median TyG index of 9.1 [8.6,9.5]. The TyG index was nonlinearly associated with in-hospital and one-year mortality risk in populations within the specified range. CONCLUSION: This study shows that TyG is a predictor of one-year mortality and in-hospital mortality in ICU patients with CAD and CKD and inform the development of new interventions to improve outcomes. In the high-risk group, TyG might be a valuable tool for risk categorization and management. Further research is required to confirm these results and identify the mechanisms behind the link between TyG and mortality in CAD and CKD patients.

CsMYBL2 homologs modulate the light and temperature stress-regulated anthocyanin and catechins biosynthesis in tea plants (Camellia sinensis).

Anthocyanin and catechin production in tea (Camellia sinensis) leaves can positively affect tea quality; however, their regulatory mechanisms are not fully understood. Here we report that, while the CsMYB75- or CsMYB86-directed MYB-bHLH-WD40 (MBW) complexes differentially activate anthocyanin or catechin biosynthesis in tea leaves, respectively, CsMYBL2a and CsMYBL2b homologs negatively modified the light- and temperature-induced anthocyanin and catechin production in both Arabidopsis and tea plants. The MBW complexes activated both anthocyanin synthesis genes and the downstream repressor genes CsMYBL2a and CsMYBL2b. Overexpression of CsMYBL2b, but not CsMYBL2a, repressed Arabidopsis leaf anthocyanin accumulation and seed coat proanthocyanin production. CsMYBL2b strongly and CsMYBL2a weakly repressed the activating effects of CsMYB75/CsMYB86 on CsDFR and CsANS, due to their different EAR and TLLLFR domains and interactions with CsTT8/CsGL3, interfering with the functions of activating MBW complexes. CsMYBL2b and CsMYBL2a in tea leaves play different roles in fine-tuning CsMYB75/CsMYB86-MBW activation of biosynthesis of anthocyanins and catechins, respectively. The CsbZIP1-CsmiR858a-CsMYBL2 module mediated the UV-B- or cold-activated CsMYB75/CsMYB86 regulation of anthocyanin/catechin biosynthesis by repressing CsMYBL2a and CsMYBL2b. Similarly, the CsCOP1-CsbZIP1-CsPIF3 module, and BR signaling as well, mediated the high temperature repression of anthocyanin and catechin biosynthesis through differentially upregulating CsMYBL2b and CsMYBL2a, respectively. The present study provides new insights into the complex regulatory networks in environmental stress-modified flavonoid production in tea plant leaves.

The SlDOG1 Affect Biosynthesis of Steroidal Glycoalkaloids by Regulating GAME Expression in Tomato.

Steroidal alkaloids (SAs) and steroidal glycoalkaloids (SGAs) are common constituents of plant species belonging to the Solanaceae family. However, the molecular mechanism regulating the formation of SAs and SGAs remains unknown. Here, genome-wide association mapping was used to elucidate SA and SGA regulation in tomatoes: a SlGAME5-like glycosyltransferase (Solyc10g085240) and the transcription factor SlDOG1 (Solyc10g085210) were significantly associated with steroidal alkaloid composition. In this study, it was found that rSlGAME5-like can catalyze a variety of substrates for glycosidation and can catalyze SA and flavonol pathways to form O-glucoside and O-galactoside in vitro. The overexpression of SlGAME5-like promoted α-tomatine, hydroxytomatine, and flavonol glycoside accumulation in tomatoes. Furthermore, assessments of natural variation combined with functional analyses identified SlDOG1 as a major determinant of tomato SGA content, which also promoted SA and SGA accumulation via the regulation of GAME gene expression. This study provides new insights into the regulatory mechanisms underlying SGA production in tomatoes.

The clinical significance of circulating glucose-regulated protein 78, Caspase-3, and C/EBP homologous protein levels in patients with heart failure.

Background and aims: The destruction of endoplasmic reticulum (ER) homeostasis leads to heart failure (HF), which further aggravates ER stress. Limited data are available on the levels of ER stress markers in HF patients in clinical practice. This study aimed to determine the clinical significance of the ER stress markers, glucose-regulated protein 78 (GRP78), Caspase-3, and C/EBP homologous protein (CHOP), in predicting HF and its severity. Materials and methods: A total of 62 patients with HF and 44 healthy controls were enrolled in the study, and all participants were followed-up for 2 years. Results: Serum GRP78, Caspase-3, and CHOP levels were significantly higher in patients with HF than those in healthy controls. The level of GRP78 increased with the severity of HF. GRP78 levels were negatively correlated with left ventricular ejection fraction, and positively correlated with N-terminal B-type natriuretic peptide, D-dimer, and lactic acid. Serum GRP78 and Caspase-3 levels showed moderate predictive values for HF patients. Conclusion: ER stress markers, GRP78 and Caspase-3, had a certain predictive value in HF and can be used as serum biomarkers for the diagnosis of HF. Additionally, GRP78 showed a certain predictive value in HF severity.

The prediction of in-hospital mortality in chronic kidney disease patients with coronary artery disease using machine learning models.

OBJECTIVE: Chronic kidney disease (CKD) patients with coronary artery disease (CAD) in the intensive care unit (ICU) have higher in-hospital mortality and poorer prognosis than patients with either single condition. The objective of this study is to develop a novel model that can predict the in-hospital mortality of that kind of patient in the ICU using machine learning methods. METHODS: Data of CKD patients with CAD were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Boruta algorithm was conducted for the feature selection process. Eight machine learning algorithms, such as logistic regression (LR), random forest (RF), Decision Tree, K-nearest neighbors (KNN), Gradient Boosting Decision Tree Machine (GBDT), Support Vector Machine (SVM), Neural Network (NN), and Extreme Gradient Boosting (XGBoost), were conducted to construct the predictive model for in-hospital mortality and performance was evaluated by average precision (AP) and area under the receiver operating characteristic curve (AUC). Shapley Additive Explanations (SHAP) algorithm was applied to explain the model visually. Moreover, data from the Telehealth Intensive Care Unit Collaborative Research Database (eICU-CRD) were acquired as an external validation set. RESULTS: 3590 and 1657 CKD patients with CAD were acquired from MIMIC-IV and eICU-CRD databases, respectively. A total of 78 variables were selected for the machine learning model development process. Comparatively, GBDT had the highest predictive performance according to the results of AUC (0.946) and AP (0.778). The SHAP method reveals the top 20 factors based on the importance ranking. In addition, GBDT had good predictive value and a certain degree of clinical value in the external validation according to the AUC (0.865), AP (0.672), decision curve analysis, and calibration curve. CONCLUSION: Machine learning algorithms, especially GBDT, can be reliable tools for accurately predicting the in-hospital mortality risk for CKD patients with CAD in the ICU. This contributed to providing optimal resource allocation and reducing in-hospital mortality by tailoring precise management and implementation of early interventions.

A glutathione S-transferase GhTT19 determines flower petal pigmentation via regulating anthocyanin accumulation in cotton.

Anthocyanin accumulations in the flowers can improve seed production of hybrid lines, and produce higher commodity value in cotton fibre. However, the genetic mechanism underlying the anthocyanin pigmentation in cotton petals is poorly understood. Here, we showed that the red petal phenotype was introgressed from Gossypium bickii through recombination with the segment containing the R3 bic region in the A07 chromosome of Gossypium hirsutum variety LR compared with the near-isogenic line of LW with white flower petals. The cyanidin-3-O-glucoside (Cy3G) was the major anthocyanin in red petals of cotton. A GhTT19 encoding a TT19-like GST was mapped to the R3 bic site associated with red petals via map-based cloning, but GhTT19 homologue gene from the D genome was not expressed in G. hirsutum. Intriguingly, allelic variations in the promoters between GhTT19LW and GhTT19LR , rather than genic regions, were found as genetic causal of petal colour variations. GhTT19-GFP was found localized in both the endoplasmic reticulum and tonoplast for facilitating anthocyanin transport. An additional MYB binding element found only in the promoter of GhTT19LR , but not in that of GhTT19LW , enhanced its transactivation by the MYB activator GhPAP1. The transgenic analysis confirmed the function of GhTT19 in regulating the red flower phenotype in cotton. The essential light signalling component GhHY5 bonded to and activated the promoter of GhPAP1, and the GhHY5-GhPAP1 module together regulated GhTT19 expression to mediate the light-activation of petal anthocyanin pigmentation in cotton. This study provides new insights into the molecular mechanisms for anthocyanin accumulation and may lay a foundation for faster genetic improvement of cotton.

Regulation Mechanism of Plant Pigments Biosynthesis: Anthocyanins, Carotenoids, and Betalains.

Anthocyanins, carotenoids, and betalains are known as the three major pigments in the plant kingdom. Anthocyanins are flavonoids derived from the phenylpropanoid pathway. They undergo acylation and glycosylation in the cytoplasm to produce anthocyanin derivatives and deposits in the cytoplasm. Anthocyanin biosynthesis is regulated by the MBW (comprised by R2R3-MYB, basic helix-loop-helix (bHLH) and WD40) complex. Carotenoids are fat-soluble terpenoids whose synthetic genes also are regulated by the MBW complex. As precursors for the synthesis of hormones and nutrients, carotenoids are not only synthesized in plants, but also synthesized in some fungi and bacteria, and play an important role in photosynthesis. Betalains are special water-soluble pigments that exist only in Caryophyllaceae plants. Compared to anthocyanins and carotenoids, the synthesis and regulation mechanism of betalains is simpler, starting from tyrosine, and is only regulated by MYB (myeloblastosis). Recently, a considerable amount of novel information has been gathered on the regulation of plant pigment biosynthesis, specifically with respect to aspects. In this review, we summarize the knowledge and current gaps in our understanding with a view of highlighting opportunities for the development of pigment-rich plants.

Comparative Metabolomics Reveals Key Determinants in the Flavor and Nutritional Value of Coconut by HS-SPME/GC-MS and UHPLC-MS/MS.

Coconut is a tropical fruit whose flesh has high flavor quality and nutritional value; however, the differences between coconut varieties are still unclear. Here, volatiles and non-volatiles were profiled at three ripening stages by HS-SPME/GC-MS and UHPLC-MS/MS in two coconut varieties (Hainan Tall, HT and Green Dwarf, GD). Four metabolite classes of volatiles were associated with good aroma including hydrocarbons, benzenoids, alcohols and esters, and these volatiles were generally higher in GD, especially at 7 and 9 months of coconut growth. Pathway-based metabolomics revealed that flavonols and their derivatives were significantly enriched in HT, and some of these metabolites were key determinants of HT flesh bitterness, including kaempferol 7-O-glucoside, a known bitter metabolite. Despite the overall accumulation of amino acids, including L-alanine, L-serine and L-methionine in GD, comparative metabolomics revealed that HT flesh provides a higher content of vitamins than GD. This study sheds light on the metabolic pathways and key metabolites differentiating the flesh flavor quality and nutritional value among coconut varieties, and reveals the possible mechanisms of flavor formation and regulation in coconut fruits.

Integrated Metabolomics and Transcriptomics Analyses Reveal the Metabolic Differences and Molecular Basis of Nutritional Quality in Landraces and Cultivated Rice.

Rice (Oryza sativa L.) is one of the most globally important crops, nutritionally and economically. Therefore, analyzing the genetic basis of its nutritional quality is a paramount prerequisite for cultivating new varieties with increased nutritional health. To systematically compare the nutritional quality differences between landraces and cultivated rice, and to mine key genes that determine the specific nutritional traits of landraces, a seed metabolome database of 985 nutritional metabolites covering amino acids, flavonoids, anthocyanins, and vitamins by a widely targeted metabolomic approach with 114 rice varieties (35 landraces and 79 cultivars) was established. To further reveal the molecular mechanism of the metabolic differences in landrace and cultivated rice seeds, four cultivars and six landrace seeds were selected for transcriptome and metabolome analysis during germination, respectively. The integrated analysis compared the metabolic profiles and transcriptomes of different types of rice, identifying 358 differentially accumulated metabolites (DAMs) and 1982 differentially expressed genes (DEGs), establishing a metabolite-gene correlation network. A PCA revealed anthocyanins, flavonoids, and lipids as the central differential nutritional metabolites between landraces and cultivated rice. The metabolite-gene correlation network was used to screen out 20 candidate genes postulated to be involved in the structural modification of anthocyanins. Five glycosyltransferases were verified to catalyze the glycosylation of anthocyanins by in vitro enzyme activity experiments. At the same time, the different mechanisms of the anthocyanin synthesis pathway and structural diversity in landrace and cultivated rice were systematically analyzed, providing new insights for the improvement and utilization of the nutritional quality of rice landrace varieties.

Diverse roles of MYB transcription factors in regulating secondary metabolite biosynthesis, shoot development, and stress responses in tea plants (Camellia sinensis).

Tea (Camellia sinensis) is concocted from tea plant shoot tips that produce catechins, caffeine, theanine, and terpenoids, which collectively determine the rich flavors and health benefits of the infusion. However, little is known about the integrated regulation of shoot tip development and characteristic secondary metabolite biosynthesis in tea plants. Here, we demonstrate that MYB transcription factors (TFs) play key and yet diverse roles in regulating leaf and stem development, secondary metabolite biosynthesis, and environmental stress responses in tea plants. By integrating transcriptomic and metabolic profiling data in different tissues at a series of developmental stages or under various stress conditions, alongside biochemical and genetic analyses, we predicted the MYB TFs involved in regulating shoot development (CsMYB2, 98, 107, and 221), epidermal cell initiation (CsMYB184, 41, 139, and 219), stomatal initiation (CsMYB113 and 153), and the biosynthesis of flavonoids (including catechins, anthocyanins, and flavonols; CsMYB8 and 99), caffeine (CsMYB85 and 86), theanine (CsMYB9 and 49), carotenoids (CsMYB110), mono-/sesquiterpenoid volatiles (CsMYB68, 147, 148, and 193), lignin (CsMYB164 and 192), and indolic compounds (CsMYB139, 162, and 198), as well as the MYB TFs that are likely involved in hormone signaling-mediated environmental stress and defense responses. We characterized the functions of some key MYBs in regulating flavonoid and carotenoid biosynthesis for tea quality and flavor. This study provides a cross-family analysis of MYBs in tea alongside new insights into the coordinated regulation of tea plant shoot development and secondary metabolism, paving the way towards understanding of tea quality trait formation and genetic improvement of quality tea plants.

Irisin alleviates high glucose-induced hypertrophy in H9c2 cardiomyoblasts by inhibiting endoplasmic reticulum stress.

BACKGROUND: Endoplasmic reticulum stress (ERS) plays an important role in the process of myocardial hypertrophy in diabetic cardiomyopathy (DCM). Irisin, a novel cytokine, has been found to protect against cardiac diastolic dysfunction in DCM. We aimed to investigate the role of irisin in cardiac hypertrophy and to elucidate the underlying mechanisms. METHODS: H9c2 cells were induced with 33 mM glucose to construct a cardiac hypertrophy cell model, which was then treated with irisin in the presence or absence of the ERS inducer tunicamycin (TM). The cell surface area was measured by FITC-phalloidin staining. The atrial natriuretic peptide levels were detected by an enzyme-linked immunosorbent assay. Furthermore, the expression of the ERS-related proteins, P-PERK, PERK, IRE1α and GRP78, was detected by western blotting. RESULTS: Irisin significantly reduced myocardial hypertrophy and suppressed high glucose (HG)-induced oxidative stress. Meanwhile, the protective effect of irisin on cardiomyoblasts was reversed by the ERS inducer, TM. Additionally, we detected ERS-associated signaling pathway proteins and found that irisin significantly reduced the protein expression levels of GRP78 and p-PERK/PERK. CONCLUSION: These results suggest that irisin ameliorates HG-induced cardiac hypertrophy by inhibiting ERS.