Response Surface Optimization for Water-Assisted Extraction of Two Saponins from Paris polyphylla var. yunnanensis Leaves.

The process of extracting polyphyllin II and polyphyllin VII by water-assisted extraction was established and optimized in this study. Response surface methodology was used to establish a prediction model to optimize the extraction conditions. Based on the one-way test, the Box-Behnken design with three factors and three levels was used for the experimental program, and the composition analysis was carried out by high-performance liquid chromatography (HPLC). The optimal extraction conditions for polyphyllin II and polyphyllin VII were as follows: extraction time of 57 and 21 min, extraction temperature of 36 and 32 °C, solid-to-liquid ratio of 1:10 and 1:5 g/mL, respectively, and the yields of polyphyllin II and polyphyllin VII were 1.895 and 5.010%, which was similar to the predicted value of 1.835 and 4.979%. The results of the ANOVA showed that the model fit was good, and the Box-Behnken response surface method could optimize the water-assisted extraction of saponins from the leaves of Paris polyphylla var. yunnanensis. This study provides a theoretical basis for the application of polyphyllin II and polyphyllin VII in pharmaceutical production.

Dynamics of imprinted genes and their epigenetic mechanisms in castor bean seed with persistent endosperm.

Genomic imprinting refers to parent-of-origin-dependent gene expression and primarily occurs in the endosperm of flowering plants, but its functions and epigenetic mechanisms remain to be elucidated in eudicots. Castor bean, a eudicot with large and persistent endosperm, provides an excellent system for studying the imprinting. Here, we identified 131 imprinted genes in developing endosperms and endosperm at seed germination phase of castor bean, involving into the endosperm development, accumulation of storage compounds and specially seed germination. Our results showed that the transcriptional repression of maternal allele of DNA METHYLTRANSFERASE 1 (MET1) may be required for maternal genome demethylation in the endosperm. DNA methylation analysis showed that only a small fraction of imprinted genes was associated with allele-specific DNA methylation, and most of them were closely associated with constitutively unmethylated regions (UMRs), suggesting a limited role for DNA methylation in controlling genomic imprinting. Instead, histone modifications can be asymmetrically deposited in maternal and paternal genomes in a DNA methylation-independent manner to control expression of most imprinted genes. These results expanded our understanding of the occurrence and biological functions of imprinted genes and showed the evolutionary flexibility of the imprinting machinery and mechanisms in plants.

Prevalence of comorbid depression and associated factors among hospitalized patients with type 2 diabetes mellitus in Hunan, China.

BACKGROUND: Depression and diabetes are major health challenges, with heavy economic social burden, and comorbid depression in diabetes could lead to a wide range of poor health outcomes. Although many descriptive studies have highlighted the prevalence of comorbid depression and its associated factors, the situation in Hunan, China, remains unclear. Therefore, this study aimed to identify the prevalence of comorbid depression and associated factors among hospitalized type 2 diabetes mellitus (T2DM) patients in Hunan, China. METHODS: This cross-sectional study involved 496 patients with T2DM who were referred to the endocrinology inpatient department of Xiangya Hospital affiliated to Central South University, Hunan. Participants' data on socio-demographic status, lifestyle factors, T2DM-related characteristics, and social support were collected. Depression was evaluated using the Hospital Anxiety and Depression Scale-depression subscale. All statistical analyses were conducted using the R software version 4.2.1. RESULTS: The prevalence of comorbid depression among hospitalized T2DM patients in Hunan was 27.22% (95% Confidence Interval [CI]: 23.3-31.1%). Individuals with depression differed significantly from those without depression in age, educational level, per capita monthly household income, current work status, current smoking status, current drinking status, regular physical activity, duration of diabetes, hypertension, chronic kidney disease, stroke, fatty liver, diabetic nephropathy, diabetic retinopathy, insulin use, HbA1c, and social support. A multivariable logistic regression model showed that insulin users (adjusted OR = 1.86, 95% CI: 1.02-3.42) had a higher risk of depression, while those with regular physical activity (adjusted OR = 0.48, 95% CI: 0.30-0.77) or greater social support (adjusted OR = 0.20, 95% CI: 0.11-0.34) had a lower risk of depression. The area under the curve of the receiver operator characteristic based on this model was 0.741 with a sensitivity of 0.785 and specificity of 0.615. CONCLUSIONS: Depression was moderately prevalent among hospitalized T2DM patients in Hunan, China. Insulin treatment strategies, regular physical activity, and social support were significantly independently associated with depression, and the multivariable model based on these three factors demonstrated good predictivity, which could be applied in clinical practice.

Epigenetic regulation of seed-specific gene expression by DNA methylation valleys in castor bean.

BACKGROUND: Understanding the processes governing angiosperm seed growth and development is essential both for fundamental plant biology and for agronomic purposes. Master regulators of angiosperm seed development are expressed in a seed-specific manner. However, it is unclear how this seed specificity of transcription is established. In some vertebrates, DNA methylation valleys (DMVs) are highly conserved and strongly associated with key developmental genes, but comparable studies in plants are limited to Arabidopsis and soybean. Castor bean (Ricinus communis) is a valuable model system for the study of seed biology in dicots and source of economically important castor oil. Unlike other dicots such as Arabidopsis and soybean, castor bean seeds have a relatively large and persistent endosperm throughout seed development, representing substantial structural differences in mature seeds. Here, we performed an integrated analysis of RNA-seq, whole-genome bisulfite sequencing, and ChIP-seq for various histone marks in the castor bean. RESULTS: We present a gene expression atlas covering 16 representative tissues and identified 1162 seed-specific genes in castor bean (Ricinus communis), a valuable model for the study of seed biology in dicots. Upon whole-genome DNA methylation analyses, we detected 32,567 DMVs across five tissues, covering ~33% of the castor bean genome. These DMVs are highly hypomethylated during development and conserved across plant species. We found that DMVs have the potential to activate transcription, especially that of tissue-specific genes. Focusing on seed development, we found that many key developmental regulators of seed/endosperm development, including AGL61, AGL62, LEC1, LEC2, ABI3, and WRI1, were located within DMVs. ChIP-seq for five histone modifications in leaves and seeds clearly showed that the vast majority of histone modification peaks were enriched within DMVs, and their remodeling within DMVs has a critical role in the regulation of seed-specific gene expression. Importantly, further experiment analysis revealed that distal DMVs may act as cis-regulatory elements, like enhancers, to activate downstream gene expression. CONCLUSIONS: Our results point to the importance of DMVs and special distal DMVs behaving like enhancers, in the regulation of seed-specific genes, via the reprogramming of histone modifications within DMVs. Furthermore, these results provide a comprehensive understanding of the epigenetic regulator roles in seed development in castor bean and other important crops.

Attitudes toward depression among rural primary healthcare providers in hunan areas, China: a cross sectional study.

BACKGROUND: Mental health services are not sufficient for depression patients in rural areas of China, training in mental health knowledge for primary healthcare providers has been encouraged, but the effect of this encouragement has rarely been reported. METHODS: A cross-sectional survey was conducted in primary healthcare facilities that sought to include all the primary healthcare providers (registered physicians and nurses) in two cities in Hunan province, China by administering questionnaires that covered depression symptoms, typical depression cases, and the Revised Depression Attitude Questionnaire. RESULTS: In total, 315 primary healthcare providers agreed to participate in the study and finished the questionnaires, of which 12.1% had training in depression. In addition, 62.9% of the rural primary healthcare providers were able to recognize most general depression symptoms, and 8.3% were able to recognize all general depression symptoms. The primary healthcare providers in the survey held a neutral to slightly negative attitude towards depression as indicated by their professional confidence (mean scores 16.51 ± 4.30), therapeutic optimism/pessimism (mean scores 29.02 ± 5.98), and general perspective (mean scores 18.12 ± 3.12) scores. Fewer rural primary healthcare providers knew (28.3%) or applied (2.9%) psychological intervention in the clinic. CONCLUSIONS: Our study indicated that primary healthcare providers knew about general depression symptoms, but lacked psychological intervention skills and held low confidence in and pessimistic attitudes toward depression care. We therefore speculate that existing psychological training for primary healthcare providers is insufficient in quantity and quality, making the need to explore more effective types of training urgently.

Function and Characteristic Analysis of Candidate PEAR Proteins in Populus yunnanensis.

PEAR proteins are a type of plant-specific DNA binding with one finger (Dof) transcription factors that play a key role in the regulation of plant growth, especially during phloem cell growth and seed germination in Arabidopsis. However, the identification, characteristics and function of PEAR proteins, particularly in woody plants, need to be further studied. In the present study, 43 candidate PEAR proteins harboring the conserved Zf-Dof domain were obtained in Populus yunnanensis. Based on phylogenetic and structural analysis, 10 representative PEAR candidates were selected, belonging to different phylogenetic groups. The functions of PEAR proteins in the stress response, signal transduction, and growth regulation of stem cambium and roots undergoing vigorous cell division in Arabidopsis were revealed based on their expression patterns as characterized by qRT-PCR analysis, in accordance with the results of cis-element analysis. In vitro experiments showed that the interaction of transcription factor (E2F) and cyclin indirectly reflects the growth regulation function of PEAR through light signaling and cell-cycle regulation. Therefore, our results provide new insight into the identity of PEAR proteins and their function in stress resistance and vigorous cell division regulation of tissues in P. yunnanensis, which may serve as a basis for further investigation of the functions and characteristics of PEAR proteins in other plants.

Functional Genome Analyses Reveal the Molecular Basis of Oil Accumulation in Developing Seeds of Castor Beans.

Castor (Ricinus communis L.) seeds produce abundant ricinoleic acid during seed maturation, which is important for plant development and human demands. Ricinoleic acid, as a unique hydroxy fatty acid (HFA), possesses a distinct bond structure that could be used as a substitute for fossil fuels. Here, we identified all homologous genes related to glycolysis, hydroxy fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in castor seeds. Furthermore, we investigated their expression patterns globally during five seed development stages. We characterized a total of 66 genes involved in the glycolysis pathway, with the majority exhibiting higher expression levels during the early stage of castor bean seed development. This metabolic process provided abundant acetyl-CoA for fatty acid (FA) biosynthesis. Subsequently, we identified 82 genes involved in the processes of de novo FA biosynthesis and TAG assembly, with the majority exhibiting high expression levels during the middle or late stages. In addition, we examined the expression patterns of the transcription factors involved in carbohydrate and oil metabolism. For instance, RcMYB73 and RcERF72 exhibited high expression levels during the early stage, whereas RcWRI1, RcABI3, and RcbZIP67 showed relatively higher expression levels during the middle and late stages, indicating their crucial roles in seed development and oil accumulation. Our study suggests that the high HFA production in castor seeds is attributed to the interaction of multiple genes from sugar transportation to lipid droplet packaging. Therefore, this research comprehensively characterizes all the genes related to glycolysis, fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in the castor and provides novel insight into exploring the genetic mechanisms underlying seed oil accumulation in the endosperm of castor beans.

Global Transcriptomic Analyses Provide New Insight into the Molecular Mechanisms of Endocarp Formation and Development in Iron Walnut (Juglans sigillata Dode).

Iron walnut (Juglans sigillata Dode) is a native species in southwestern China that exhibits variation in both fruit morphology and shell thickness. However, the underlying molecular processes controlling hardened endocarp development in walnut has not yet been reported. Here, we generated transcriptional profiles of iron walnut endocarp at three developmental stages using "Dapao", the most common commercial variety. Using pairwise comparisons between these three stages, a total of 8555 non-redundant differentially expressed genes (DEGs) were identified, and more than one-half of the total DEGs exhibited significant differential expression in stage I as compared with stage II or stage III, suggesting that the first stage may ultimately determine the final characteristics of the mature walnut shell. Furthermore, in the clustering analysis of the above DEGs, 3682, 2349, and 2388 genes exhibited the highest expression in stages I, II, and III, respectively. GO enrichment analysis demonstrated that the major transcriptional variation among the three developmental stages was caused by differences in cell growth, plant hormones, metabolic process, and phenylpropanoid metabolism. Namely, using the tissue-specific expression analysis and a gene co-expression network, we identified MADS-box transcription factor JsiFBP2 and bHLH transcription factor JsibHLH94 as candidate regulators of endocarp formation in the early stage, and JsiNAC56 and JsiMYB78 might play key roles in regulating the lignification process of endocarp in the late stage. This study provides useful information for further research to dissect the molecular mechanisms governing the shell formation and development of iron walnut.

Prevalence of Anxiety and Associated Factors Among Inpatients with Type 2 Diabetes Mellitus in China: A Cross-Sectional Study.

This study aimed to investigate the prevalence of anxiety and its associated factors among inpatients with type 2 diabetes mellitus (T2DM) in China. This study was a cross-sectional study. Inpatients with T2DM admitted to the Endocrinology Department of Xiangya Hospital, Central South University in Hunan Province of China from March 2021 to December 2021 were consecutively included in this study. Participants were interviewed to obtain the data on socio-demographic characteristics, lifestyle characteristics, T2DM-related information, and social support. Anxiety was measured using the Hospital Anxiety and Depression Scale-anxiety subscale by experienced physicians. Multivariable logistic regression analysis was used to estimate the independent contribution of each independent variable to anxiety. A total of 496 inpatients with T2DM were included in this study. The prevalence of anxiety was 21.8% (95% confidence interval [CI]: 18.1%-25.4%). The results of multivariable logistic regression analysis indicated that age of at least 60 (adjusted odd ratio [aOR] = 1.79, 95% CI: 1.04-3.08), and having diabetes specific complications (aOR = 4.78, 95% CI: 1.02-22.44) were risk factors for anxiety, and an educational level of high school or above (aOR = 0.55, 95% CI: 0.31-0.99), regular physical activity (aOR = 0.36, 95% CI: 0.22-0.58), and high social support (aOR = 0.30, 95% CI: 0.17-0.53) were protective factors for anxiety. A predictive model based on these five variables showed good performance (area under the curve = 0.80). Almost one in five inpatients with T2DM suffered from anxiety in China. Age, educational level, regular physical activity, diabetes specific complications, and social support were independently associated with anxiety.

Engineering an oilseed crop for hyper-accumulation of carotenoids in the seeds without using a traditional marker gene.

KEY MESSAGE: Ketocarotenoids were synthesized successfully in Camelina sativa seeds by genetic modification without using a traditional selection marker genes. This method provided an interesting tool for metabolic engineering of seed crops. Camelina sativa (L.) Crantz is an important oil crop with many excellent agronomic traits. This model oil plant has been exploited to accumulate value-added bioproducts using genetic manipulation that depends on antibiotic- or herbicide-based selection marker genes (SMG), one of the major concerns for genetically modified foods. Here we reported metabolic engineering of C. sativa to synthesize red ketocarotenoids that could serve as a reporter to visualize transgenic events without using a traditional SMG. Overexpression of a non-native ß-carotene ketolase gene coupled with three other carotenogenous genes (phytoene synthase, ß-carotene hydroxylase, and Orange) in C. sativa resulted in production of red seeds that were visibly distinguishable from the normal yellow ones. Constitutive expression of the transgenes led to delayed plant development and seed germination. In contrast, seed-specific transformants demonstrated normal growth and seed germination despite the accumulation of up to 70-fold the level of carotenoids in the seeds compared to the controls, including significant amounts of astaxanthin and keto-lutein. As a result, the transgenic seed oils exhibited much higher antioxidant activity. No significant changes were found in the profiles of fatty acids between transgenic and control seeds. This study provided an interesting tool for metabolic engineering of seed crops without using a disputed SMG.

Anti-Inflammatory and Anti-Oxidative Effects of Isorhamnetin for Protection Against Lung Injury in a Rat Model of Heatstroke in a Dry-Heat Environment.

BACKGROUND Isorhamnetin is a natural flavonoid compound with anti-inflammatory and antioxidant properties. However, its roles in alleviating lung injury associated with heatstroke remain unclear. Therefore, this study aimed to evaluate the protective effects of different isorhamnetin doses on lung injury in heatstroke rat models exposed to a dry-heat environment. MATERIAL AND METHODS Fifty Sprague-Dawley rats were randomly divided into 5 groups: normal control (0.9% saline), heatstroke (0.5% CMCNa), and isorhamnetin (25, 50, and 100 mg/kg) groups; treatments were administered by gavage daily for 7 days. All rats, except those in the control group, were exposed to a dry-heat environment (41±1°C, 10±2% relative humidity) for 150 min to induce heatstroke. Pathological changes, ultrastructure, edema, inflammation, and oxidative stress in the lungs were assessed. RESULTS Compared with the heatstroke group, rats treated with 100 mg/kg isorhamnetin showed amelioration of histopathological and ultrastructural changes in the lungs; decreased lung injury scores (P<0.05) and wet/dry weight ratios (P<0.01); lower levels of phospho-nuclear factor-kappaB (P<0.05), high-mobility group box 1 (P<0.01), tumor necrosis factor-alpha (P<0.01), interleukin (IL)-1ß (P<0.01), and IL-6 (P<0.01); lower malondialdehyde contents (P<0.01); and higher superoxide dismutase (P<0.01) and catalase activities (P<0.05). CONCLUSIONS In a dry-heat environment, isorhamnetin protected against lung injury in heatstroke rat models via anti-inflammatory and anti-oxidative mechanisms.

Separation and Purification of Two Saponins from Paris polyphylla var. yunnanensis by a Macroporous Resin.

An effective method for separating and purifying critical saponins (polyphyllin II and polyphyllin VII) from a Paris polyphylla var. yunnanensis extract was developed in this study which was environmentally friendly and economical. Static adsorption kinetics, thermodynamics, and the dynamic adsorption-desorption of macroporous resins were investigated, and then the conditions of purification and separation were optimized by fitting with an adsorption thermodynamics equation and a kinetic equation. Effective NKA-9 resin from seven macroporous resins was screened out to separate and purify the two saponins. The static adsorption and dynamic adsorption were chemical and physical adsorption dual-processes on the NKA-9 resin. Under the optimum parameters, the contents of polyphyllin II and polyphyllin VII in the product were 17.3-fold and 28.6-fold those in plant extracts, respectively. The total yields of the two saponins were 93.16%. This research thus provides a theoretical foundation for the large-scale industrial production of the natural drugs polyphyllin II and polyphyllin VII.

Blue genome: chromosome-scale genome reveals the evolutionary and molecular basis of indigo biosynthesis in Strobilanthes cusia.

Natural plant dyes have been developed and used across many traditional societies worldwide. The blue pigment indigo has seen widespread usage across South America, Egypt, Europe, India and China for thousands of years, mainly extracted from indigo-rich plants. The utilization and genetic engineering of indigo in industries and ethnobotanical studies on the effects of cultural selection on plant domestication are limited due to lack of relevant genetic and genomic information of dye plants. Strobilanthes cusia (Acanthaceae) is a typical indigo-rich plant important to diverse ethnic cultures in many regions of Asia. Here we present a chromosome-scale genome for S. cusia with a genome size of approximately 865 Mb. About 79% of the sequences were identified as repetitive sequences and 32 148 protein-coding genes were annotated. Metabolic analysis showed that the main indigoid pigments (indican, indigo and indirubin) were mainly synthesized in the leaves and stems of S. cusia. Transcriptomic analysis revealed that the expression level of genes encoding metabolic enzymes such as monooxygenase, uridine diphosphate-glycosyltransferase and ß-glucosidase were significantly changed in leaves and stems compared with root tissues, implying their participation in indigo biosynthesis. We found that several gene families involved in indigo biosynthesis had undergone an expansion in number, with functional differentiation likely facilitating indigo biosynthesis in S. cusia. This study provides insight into the physiological and molecular bases of indigo biosynthesis, as well as providing genomic data that provide the basis for further study of S. cusia cultivation by Asia's traditional textile producers.

The 3-ketoacyl-CoA synthase WFL is involved in lateral organ development and cuticular wax synthesis in Medicago truncatula.

KEY MESSAGE: A 3-ketoacyl-CoA synthase involved in biosynthesis of very long chain fatty acids and cuticular wax plays a vital role in aerial organ development in M. truncatula. Cuticular wax is composed of very long chain fatty acids and their derivatives. Defects in cuticular wax often result in organ fusion, but little is known about the role of cuticular wax in compound leaf and flower development in Medicago truncatula. In this study, through an extensive screen of a Tnt1 retrotransposon insertion population in M. truncatula, we identified four mutant lines, named wrinkled flower and leaf (wfl) for their phenotype. The phenotype of the wfl mutants is caused by a Tnt1 insertion in Medtr3g105550, encoding 3-ketoacyl-CoA synthase (KCS), which functions as a rate-limiting enzyme in very long chain fatty acid elongation. Reverse transcription-quantitative PCR showed that WFL was broadly expressed in aerial organs of the wild type, such as leaves, floral organs, and the shoot apical meristem, but was expressed at lower levels in roots. In situ hybridization showed a similar expression pattern, mainly detecting the WFL transcript in epidermal cells of the shoot apical meristem, leaf primordia, and floral organs. The wfl mutant leaves showed sparser epicuticular wax crystals on the surface and increased water permeability compared with wild type. Further analysis showed that in wfl leaves, the percentage of C20:0, C22:0, and C24:0 fatty acids was significantly increased, the amount of cuticular wax was markedly reduced, and wax constituents were altered compared to the wild type. The reduced formation of cuticular wax and wax composition changes on the leaf surface might lead to the developmental defects observed in the wfl mutants. These findings suggest that WFL plays a key role in cuticular wax formation and in the late stage of leaf and flower development in M. truncatula.

Chemokines in post-traumatic stress disorder: A network meta-analysis.

BACKGROUND: Previous studies on the association between chemokines concentrations and post-traumatic stress disorder (PTSD) yielded inconsistent results. Therefore, the purpose of this network meta-analysis was to summarize these results. METHODS: The databases of PubMed, Web of Science, Psyc-ARTICLES, Embase and Cochrane Library were searched for relevant articles published not later than January 15, 2020. Then, eligible studies were selected based on predefined study selection criteria. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated as group differences in chemokines concentrations. Moreover, network meta-analysis was used to rank chemokines effect values according to their respective surface under cumulative ranking curve (SUCRA) probabilities. FINDINGS: A total of 18 eligible studies that investigated the association between 9 different chemokines and PTSD were identified. They involved 1,510 patients and 2,012 controls. Results of the meta-analysis showed that the concentrations of CCL3, CCL4 and CCL5 in the PTSD patients were significantly higher than that in the controls (SMDs of 4.12, 6.11 and 1.53 respectively). However, although not statistically significant, concentrations of CCL2 tended to be lower in PTSD patients than in the controls (SMD = -0.76); whereas concentrations of CXCL12 tended to be higher in PTSD patients than in the controls (SMD = 0.37). SUCRA probabilities showed that, among all the chemokines studied, the effect of CCL5 was the highest in PTSD patients. INTERPRETATION: Concentrations of CCL3, CCL4 and CCL5 may be associated with a trauma and/or PTSD. Also, CXCL12 and CCL2 may be the underlying biomarkers for trauma and/or PTSD. Thus, future studies with large population based samples are needed to further assess these associations. In addition, future research should explore possible mechanisms underlying these associations, with the aim to develop new diagnostics for PTSD. PROSPERO CRD42019147703.

Chemokines in hepatocellular carcinoma: a meta-analysis.

Accumulating evidence suggests that chemokines may play an important role in the formation and mediating of the immune microenvironment of hepatocellular carcinoma (HCC). The purpose of this meta-analysis was to explore the differences in blood or tissues chemokines concentrations between HCC patients and controls. Online databases, namely PubMed, Web of Science, Embase and Cochrane Library, were systematically searched for relevant articles published on or before 15 January 2020. Standardized mean differences (SMDs) with corresponding 95% confidence intervals of the chemokines concentrations were calculated as group differences between the HCC patients and the controls. Sixty-five studies met the inclusion criteria for the meta-analysis. Altogether they consisted of 26 different chemokines compared between 5828 HCC patients and 4909 controls; and 12 different chemokines receptors compared between 2053 patients and 2285 controls. The results of meta-analysis indicated that concentrations of CCL20, CXCL8 and CXCR4 in the HCC patients were significantly higher than those in the controls (SMD of 6.18, 1.81 and 1.04, respectively). Therefore, higher concentration levels of CCL20, CXCL8 and CXCR4 may indicate the occurrence of HCC Future research should explore the putative mechanisms underlying this linkage. Meanwhile, attempts can be made to replicate the existing findings in prospective cohort populations and explore the cause-and-effect relationships pertaining to this linkage in order to develop new diagnostic and therapeutic strategies for HCC.

Changes and Associations of Genomic Transcription and Histone Methylation with Salt Stress in Castor Bean.

Soil salinity is a major source of abiotic plant stress, adversely affecting plant growth, development and productivity. Although the physiological and molecular mechanisms that underlie plant responses to salt stress are becoming increasingly understood, epigenetic modifications, such as histone methylations and their potential regulation of the transcription of masked genes at the genome level in response to salt stress, remain largely unclear. Castor bean, an important nonedible oil crop, has evolved the capacity to grow under salt stress. Here, based on high-throughput RNA-seq and ChIP-seq data, we systematically investigated changes in genomic transcription and histone methylation using typical histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 tri-methylated lysine 27 (H3K27me3) markers in castor bean leaves subjected to salt stress. The results showed that gain or loss of histone methylation was closely associated with activated or repressed gene expression, though variations in both transcriptome and histone methylation modifications were relatively narrow in response to salt stress. Diverse salt responsive genes and switched histone methylation sites were identified in this study. In particular, we found for the first time that the transcription of the key salt-response regulator RADIALIS-LIKE SANT (RSM1), a MYB-related transcription factor involved in ABA(abscisic acid)-mediated salt stress signaling, was potentially regulated by bivalent H3K4me3-H3K27me3 modifications. Combining phenotypic variations with transcriptional and epigenetic changes, we provide a comprehensive profile for understanding histone modification, genomic transcription and their associations in response to salt stress in plants.

Comparative proteomic and transcriptomic analyses provide new insight into the formation of seed size in castor bean.

BACKGROUND: Little is known about the molecular basis of seed size formation in endospermic seed of dicotyledons. The seed of castor bean (Ricinus communis L.) is considered as a model system in seed biology studies because of its persistent endosperms throughout seed development. RESULTS: We compared the size of endosperm and endospermic cells between ZB107 and ZB306 and found that the larger seed size of ZB107 resulted from a higher cell count in the endosperm, which occupy a significant amount of the total seed volume. In addition, fresh weight, dry weight, and protein content of seeds were remarkably higher in ZB107 than in ZB306. Comparative proteomic and transcriptomic analyses were performed between large-seed ZB107 and small-seed ZB306, using isobaric tags for relative and absolute quantification (iTRAQ) and RNA-seq technologies, respectively. A total of 1416 protein species were identified, of which 173 were determined as differentially abundant protein species (DAPs). Additionally, there were 9545 differentially expressed genes (DEGs) between ZB306 and ZB107. Functional analyses revealed that these DAPs and DEGs were mainly involved in cell division and the metabolism of carbohydrates and proteins. CONCLUSIONS: These findings suggest that both cell number and storage-component accumulation are critical for the formation of seed size, providing new insight into the potential mechanisms behind seed size formation in endospermic seeds.

Comprehensive analysis of the Ppatg3 mutant reveals that autophagy plays important roles in gametophore senescence in Physcomitrella patens.

BACKGROUND: Autophagy is an evolutionarily conserved system for the degradation of intracellular components in eukaryotic organisms. Autophagy plays essential roles in preventing premature senescence and extending the longevity of vascular plants. However, the mechanisms and physiological roles of autophagy in preventing senescence in basal land plants are still obscure. RESULTS: Here, we investigated the functional roles of the autophagy-related gene PpATG3 from Physcomitrella patens and demonstrated that its deletion prevents autophagy. In addition, Ppatg3 mutant showed premature gametophore senescence and reduced protonema formation compared to wild-type (WT) plants under normal growth conditions. The abundance of nitrogen (N) but not carbon (C) differed significantly between Ppatg3 mutant and WT plants, as did relative fatty acid levels. In vivo protein localization indicated that PpATG3 localizes to the cytoplasm, and in vitro Y2H assays confirmed that PpATG3 interacts with PpATG7 and PpATG12. Plastoglobuli (PGs) accumulated in Ppatg3, indicating that the process that degrades damaged chloroplasts in senescent gametophore cells was impaired in this mutant. RNA-Seq uncovered a detailed, comprehensive set of regulatory pathways that were affected by the autophagy mutation. CONCLUSIONS: The autophagy-related gene PpATG3 is essential for autophagosome formation in P. patens. Our findings provide evidence that autophagy functions in N utilization, fatty acid metabolism and damaged chloroplast degradation under non-stress conditions. We identified differentially expressed genes in Ppatg3 involved in numerous biosynthetic and metabolic pathways, such as chlorophyll biosynthesis, lipid metabolism, reactive oxygen species removal and the recycling of unnecessary proteins that might have led to the premature senescence of this mutant due to defective autophagy. Our study provides new insights into the role of autophagy in preventing senescence to increase longevity in basal land plants.

Is abdominal vascular calcification score valuable in predicting the occurrence of colorectal anastomotic leakage? A meta-analysis.

OBJECTIVE: Anastomotic leakage (AL) is a catastrophic surgical complication affecting the prognosis of patients after colorectal surgery. We aimed to determine the value of the arterial calcification (AC) score in predicting AL. METHODS: Medline and Embase were searched through November 2019. The odds ratio (OR) and 95% confidence interval (CI) were used to estimate the association between AC and AL after colorectal surgery. The fixed-effects model or random-effects model was adopted for data pooling. Subgroup analyses were conducted to assess the effect of different aortoiliac trajectories. RESULTS: Four studies involving 496 patients were included. The calcium volume and calcium score measurements of different trajectories revealed a significant difference with regard to the left and right common iliac arteries, the superior mesenteric artery, and the left common iliac artery. Calcification of the internal iliac artery significantly increased the risk of AL compared with no AL (OR = 1.005; 95% CI 1.002-1.009; P = 0.005), as did calcification of the left internal iliac artery (OR = 1.009; 95% CI 1.002-1.016; P = 0.011), but not of the common iliac artery (OR = 1.001; 95% CI 1.000-1.001; P = 0.317) or common and internal iliac artery (OR = 1.000; 95% CI 1.000-1.000; P = 1.000). CONCLUSIONS: AC is associated with increased risk of AL following colorectal surgery. TRIAL REGISTRATION: CRD42019141236.