Correlation between preoperative sleep disorders and postoperative delayed neurocognitive recovery in elderly patients. / è€å¹´æ‚£è€ æœ¯å‰ç¡çœ éšœç¢ä¸Žæœ¯åŽç¥žç»è®¤çŸ¥æ¢å¤å»¶è¿Ÿçš„ç›¸å ³æ€§.

OBJECTIVES: Perioperative neurocognitive disorders (PND) is one of the important factors affecting the recovery of the elderly after surgery, and sleep disorders are also one of the common diseases of the elderly. Previous studies have shown that the quality of postoperative sleep may be factor affecting postoperative cognitive function, but there are few studies on the relationship between preoperative sleep disorders and postoperative cognitive dysfunction. This study aims to explore the relationship between preoperative sleep disorders and postoperative delayed neurocognitive recovery in elderly patients, and provide references for improving the prognosis and quality of life of patients. METHODS: This study was porformed as a prospective cohort study. Elderly patients (age≥65 years old) underwent elective non-cardiac surgery at Xiangya Hospital of Central South University from October 2019 to January 2020 were selected and interviewed 1 day before the operation. The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA) were used to assess the patient's baseline cognitive status. Patients with preoperative MMSE scores of less than 24 points were excluded. For patients meeting the criteria of inclusion, Pittsburgh Sleep Quality Index (PSQI) scale was used to evaluate the patients, and the patients were divided into a sleep disorder group and a non-sleep disorder group according to the score. General data of patients were collected and intraoperative data were recorded, such as duration of surgery, anesthetic time, surgical site, intraoperative fluid input, intraoperative blood product input, intraoperative blood loss and drug use. On consecutive 5 days after surgery, Numerical Rating Scale (NRS) was used to evaluate the sleep of the previous night and the pain of the day, which were recorded as sleep NRS score and pain NRS score; Confusion Assessment Method for ICU (CAM-ICU) scale and Confusion Assessment Method (CAM) scale were used to assess the occurrence of delirium. On the 7th day after the operation, the MMSE and MoCA scales were used to evaluate cognitive function of patients. We compared the incidence of postoperative complications, the number of deaths, the number of unplanned ICU patients, the number of unplanned secondary operations, etc between the 2 groups. The baseline and prognosis of the 2 groups of patients were analyzed by univariate and multivariate logistics to analyze their correlation. RESULTS: A total of 105 patients were collected in this study, including 32 patients in the sleep disorder group and 73 patients in the non-sleep disorder group. The general information of the 2 groups, such as age, gender, body mass index, and surgery site, were not statistically significant (all P>0.05). There was no statistically significant difference in the operation time, intraoperative bleeding, the number of delirium, and sleep NRS score at 5 days after operation between the 2 groups (all P>0.05). The incidence of unplanned second surgery after surgery and the NRS pain score on the first day in the sleep disorder group were significantly higher than those in the non-sleep disorder group (P=0.002, P=0.045, respectively). A total of 20 patients (19%) in the 2 groups had postoperative delayed neurocognitive recovery on the 7th day after surgery. Among them, 11 patients (34.4%) in the sleep disorder group, 9 patients (12.3%) in the non-sleep disorder group. The incidence of delayed neurocognitive recovery in the sleep disorder group was significantly higher than that in the non-sleep disorder group (P=0.008). The incidence of postoperative infection in the sleep disorder group was also higher than that in the non-sleep disorder group (P=0.020). After controlling for the confounding factors, preoperative sleep disorders were still independently associated with postoperative delayed neurocognitive recovery (OR=3.330, 95% CI 1.063-10.431, P=0.039). CONCLUSIONS: Preoperative sleep disorders can increase the risk of delayed neurocognitive function recovery in elderly patients. Active treatment of preoperative sleep disorders may improve perioperative neurocognitive function in elderly patients.

Over-expression of poplar NAC15 gene enhances wood formation in transgenic tobacco.

BACKGROUND: NAC (NAM/ATAF/CUC) is one of the largest plant-specific transcription factor (TF) families known to play significant roles in wood formation. Acting as master gene regulators, a few NAC genes can activate secondary wall biosynthesis during wood formation in woody plants. RESULTS: In the present study, firstly, we screened 110 differentially expressed NAC genes in the leaves, stems, and roots of di-haploid Populus simonii×P. nigra by RNA-Seq. Then we identified a nucleus-targeted gene, NAC15 gene, which was one of the highly expressed genes in the stem among 110 NAC family members. Thirdly, we conducted expression pattern analysis of NAC15 gene, and observed NAC15 gene was most highly expressed in the xylem by RT-qPCR. Moreover, we transferred NAC15 gene into tobacco and obtained 12 transgenic lines overexpressing NAC15 gene (TLs). And the relative higher content of hemicellulose, cellulose and lignin was observed in the TLs compared to the control lines containing empty vector (CLs). It also showed darker staining in the culms of the TLs with phloroglucinol staining, compared to the CLs. Furthermore, the relative expression level of a few lignin- and cellulose-related genes was significantly higher in the TLs than that in the CLs. CONCLUSIONS: The overall results indicated that NAC15 gene is highly expressed in the xylem of poplar and may be a potential candidate gene playing an important role in wood formation in transgenic tobacco.

Risk factors for postoperative deep venous thrombosis in patients underwent craniotomy. / å¼€é¢ æ‰‹æœ¯åŽæ·±é™è„‰è¡€æ “å½¢æˆçš„å±é™©å› ç´ .

OBJECTIVES: To analyze the risk factors for postoperative deep vein thrombosis (DVT) in neurosurgical patients to provide the basis for the prevention of postoperative DVT. METHODS: A total of 141 patients underwent neurosurgery were enrolled. Thrombelastography (TEG) test was performed before and at the end of surgery. According to whether there was DVT formation after operation, the patients were divided into a thrombosis group and a non-thrombosis group. T-test and rank sum test were used to compare the general clinical characteristics of the 2 groups, such as age, gender, intraoperative blood loss, D-dimer, intraoperative crystal input, colloid input, blood product transfusion, operation duration, length of postoperative hospitalization. The application of chi-square test and rank-sum test were used to compared TEG main test indicators such as R and K values between the 2 groups. Logistic regression was used to analyze the possible risk factors for postoperative DVT in neurosurgical patients. RESULTS: There were significant differences in postoperative TEG index R, clotting factor function, intraoperative blood loss, hypertension or not, length of postoperative hospital stay, and postoperative absolute bed time (all P<0.05). Logistic regression analysis showed hypercoagulability, more intraoperative blood loss and longer postoperative absolute bed time were risk factors for DVT formation after craniotomy. CONCLUSIONS: Hypercoagulability in postoperative TEG test of patients is an important risk factor for the formation of postoperative DVT after neurosurgery, which can predict the occurrence of postoperative DVT to some extent.

[Prognosis in patients underwent craniotomy for aneurysm clipping with cardiovascular diseases].

OBJECTIVE: To analyze the prognostic factors for patients with or without cardiovascular diseases after craniotomy for aneurysm clipping, and to provide evidences for the improvement of perioperative management in these patients.
 Methods: We collected 297 patients who underwent craniotomy for aneurysm clipping in Xiangya Hospital of Central South University from May 2016 to February 2017. The patients were divided into two groups: the cardiovascular disease group and the non-cardiovascular disease group. The perioperative clinical data, neurological function assessments at admission and discharge and Glasgow Outcome Scale (GOS) scores of one-year-follow-up after discharge were analyzed. The primary outcome of this study was the GOS scores collected at one year after discharge. The secondary outcomes were the lengths of their ICU stay, neurological functions at discharge and adverse events morbidity during the hospitalization.
 Results: A total of 241 patients were eventually enrolled. There was no significant difference in their general data between the two groups except for their ages. The GOS scores of the one-year-follow-up were significantly different between the two groups (P=0.007). The lengths of ICU stay, neurological dysfunctions at discharge and adverse events morbidity during hospitalization were also significantly different (P=0.036, P=0.011, P=0.005, respectively). A multivariate logistic regression analysis in which GOS score was the dependent variable with age adjusted also supported the previous results that long-term prognosis was not significantly correlated with the age of patients (P>0.05), but it was correlated with cardiovascular disease and sanity at admission (P=0.001). In patients with cardiovascular diseases, there was significantly different in perioperative mortality and neurological recovery of patients who had or had not cardiovascular events (P=0.006, P=0.001, respectively).
 Conclusion: Undergoing craniotomy for aneurysm clipping, patients with cardiovascular diseases have worse outcomes in both of short and long terms. Perioperative treatments for cardiovascular disease could not only improve postoperative neurological deficits, but also reduce mortality for these patients.

The developmental transcriptome of Drosophila melanogaster.

Drosophila melanogaster is one of the most well studied genetic model organisms; nonetheless, its genome still contains unannotated coding and non-coding genes, transcripts, exons and RNA editing sites. Full discovery and annotation are pre-requisites for understanding how the regulation of transcription, splicing and RNA editing directs the development of this complex organism. Here we used RNA-Seq, tiling microarrays and cDNA sequencing to explore the transcriptome in 30 distinct developmental stages. We identified 111,195 new elements, including thousands of genes, coding and non-coding transcripts, exons, splicing and editing events, and inferred protein isoforms that previously eluded discovery using established experimental, prediction and conservation-based approaches. These data substantially expand the number of known transcribed elements in the Drosophila genome and provide a high-resolution view of transcriptome dynamics throughout development.

Novel bicyclo[3.1.0]hexane analogs as antagonists of metabotropic glutamate 2/3 receptors for the treatment of depression.

Negative modulators of metabotropic glutamate 2 & 3 receptors demonstrate antidepressant-like activity in animal models and hold promise as novel therapeutic agents for the treatment of major depressive disorder. Herein we describe our efforts to prepare and optimize a series of conformationally constrained 3,4-disubstituted bicyclo[3.1.0]hexane glutamic acid analogs as orthosteric (glutamate site) mGlu2/3 receptor antagonists. This work led to the discovery of a highly potent and efficacious tool compound 18 (hmGlu2 IC50 46±14.2nM, hmGlu3 IC50=46.1±36.2nM). Compound 18 showed activity in the mouse forced swim test with a minimal effective dose (MED) of 1mg/kg ip. While in rat EEG studies it exhibited wake promoting effects at 3 and 10mg/kg ip without any significant effects on locomotor activity. Compound 18 thus represents a novel tool molecule for studying the impact of blocking mGlu2/3 receptors both in vitro and in vivo.

Synthetic spike-in standards for RNA-seq experiments.

High-throughput sequencing of cDNA (RNA-seq) is a widely deployed transcriptome profiling and annotation technique, but questions about the performance of different protocols and platforms remain. We used a newly developed pool of 96 synthetic RNAs with various lengths, and GC content covering a 2(20) concentration range as spike-in controls to measure sensitivity, accuracy, and biases in RNA-seq experiments as well as to derive standard curves for quantifying the abundance of transcripts. We observed linearity between read density and RNA input over the entire detection range and excellent agreement between replicates, but we observed significantly larger imprecision than expected under pure Poisson sampling errors. We use the control RNAs to directly measure reproducible protocol-dependent biases due to GC content and transcript length as well as stereotypic heterogeneity in coverage across transcripts correlated with position relative to RNA termini and priming sequence bias. These effects lead to biased quantification for short transcripts and individual exons, which is a serious problem for measurements of isoform abundances, but that can partially be corrected using appropriate models of bias. By using the control RNAs, we derive limits for the discovery and detection of rare transcripts in RNA-seq experiments. By using data collected as part of the model organism and human Encyclopedia of DNA Elements projects (ENCODE and modENCODE), we demonstrate that external RNA controls are a useful resource for evaluating sensitivity and accuracy of RNA-seq experiments for transcriptome discovery and quantification. These quality metrics facilitate comparable analysis across different samples, protocols, and platforms.

Expression patterns of WRKY genes in di-haploid Populus simonii × P. nigra in response to salinity stress revealed by quantitative real-time PCR and RNA sequencing.

KEY MESSAGE: Spatio-temporal expression patterns of 13 out of 119 poplar WRKY genes indicated dynamic and tissue-specific roles of WRKY family proteins in salinity stress tolerance. To understand the expression patterns of poplar WRKY genes under salinity stress, 51 of the 119 WRKY genes were selected from di-haploid Populus simonii × P. nigra by quantitative real-time PCR (qRT-PCR). We used qRT-PCR to profile the expression of the top 13 genes under salinity stress across seven time points, and employed RNA-Seq platforms to cross-validate it. Results demonstrated that all the 13 WRKY genes were expressed in root, stem, and leaf tissues, but their expression levels and overall patterns varied notably in these tissues. Regarding overall gene expression in roots, the 13 genes were significantly highly expressed at all six time points after the treatment, reaching the plateau of expression at hour 9. In leaves, the 13 genes were similarly up-regulated from 3 to 12 h in response to NaCl treatment. In stems, however, expression levels of the 13 genes did not show significant changes after the NaCl treatment. Regarding individual gene expression across the time points and the three tissues, the 13 genes can be classified into three clusters: the lowly expressed Cluster 1 containing PthWRKY28, 45 and 105; intermediately expressed Clusters 2 including PthWRKY56, 88 and 116; and highly expressed Cluster 3 consisting of PthWRKY41, 44, 51, 61, 62, 75 and 106. In general, genes in Cluster 2 and 3 displayed a dynamic pattern of "induced amplification-recovering", suggesting that these WRKY genes and corresponding pathways may play a critical role in mediating salt response and tolerance in a dynamic and tissue-specific manner.

Relationship between obesity phenotypes and genetic determinants in a mouse model for juvenile obesity.

Obesity, a state of imbalance between lean mass and fat mass, is important for the etiology of diseases affected by the interplay of multiple genetic and environmental factors. Although genome-wide association studies have repeatedly associated genes with obesity and body weight, the mechanisms underlying the interaction between the muscle and adipose tissues remain unknown. Using 351 mice (at 10 wk of age) of an intercross population between Berlin Fat Mouse Inbred (BFMI) and C57BL/6NCrl (B6N) mice, we examined the causal relationships between genetic variations and multiple traits: body lean mass and fat mass, adipokines, and bone mineral density. Furthermore, evidence from structural equation modeling suggests causality among these traits. In the BFMI model, juvenile obesity affects lean mass and impairs bone mineral density via adipokines secreted from the white adipose tissues. While previous studies have indicated that lean mass has a causative effect on adiposity, in the Berlin Fat Mouse model that has been selected for juvenile obesity (at 9 wk of age) for >90 generations, however, the causality is switched from fat mass to lean mass. In addition, linkage studies and statistical modeling have indicated that quantitative trait loci on chromosomes 5 and 6 affect both lean mass and fat mass. These lines of evidence indicate that the muscle and adipose tissues interact with one another and the interaction is modulated by genetic variations that are shaped by selections. Experimental examinations are necessary to verify the biological role of the inferred causalities.

Genome sequencing and comparative genomics of honey bee microsporidia, Nosema apis reveal novel insights into host-parasite interactions.

BACKGROUND: The microsporidia parasite Nosema contributes to the steep global decline of honey bees that are critical pollinators of food crops. There are two species of Nosema that have been found to infect honey bees, Nosema apis and N. ceranae. Genome sequencing of N. apis and comparative genome analysis with N. ceranae, a fully sequenced microsporidia species, reveal novel insights into host-parasite interactions underlying the parasite infections. RESULTS: We applied the whole-genome shotgun sequencing approach to sequence and assemble the genome of N. apis which has an estimated size of 8.5 Mbp. We predicted 2,771 protein- coding genes and predicted the function of each putative protein using the Gene Ontology. The comparative genomic analysis led to identification of 1,356 orthologs that are conserved between the two Nosema species and genes that are unique characteristics of the individual species, thereby providing a list of virulence factors and new genetic tools for studying host-parasite interactions. We also identified a highly abundant motif in the upstream promoter regions of N. apis genes. This motif is also conserved in N. ceranae and other microsporidia species and likely plays a role in gene regulation across the microsporidia. CONCLUSIONS: The availability of the N. apis genome sequence is a significant addition to the rapidly expanding body of microsprodian genomic data which has been improving our understanding of eukaryotic genome diversity and evolution in a broad sense. The predicted virulent genes and transcriptional regulatory elements are potential targets for innovative therapeutics to break down the life cycle of the parasite.

Host CD3+ T-cells can significantly modulate phage treatment effects on bacterial bioburden in mouse models.

Wound healing is a complex system including such key players as host, microbe, and treatments. However, little is known about their dynamic interactions. Here we explored the interplay between: (1) bacterial bioburden and host immune responses, (2) bacterial bioburden and wound size, and (3) treatments and wound size, using murine models and various treatment modalities: Phosphate buffer saline (PBS or vehicle, negative control), doxycycline, and two doses of A. baumannii phage mixtures. We uncovered that the interplay between bacterial bioburden and host immune system may be bidirectional, and that there is an interaction between host CD3+ T-cells and phage dosage, which significantly impacts bacterial bioburden. Furthermore, the bacterial bioburden and wound size association is significantly modulated by the host CD3+ T-cells. When the host CD3+ T-cells (x on log10 scale) are in the appropriate range (1.35 < x < = 1.5), we observed a strong association between colony forming units (CFU) and wound size, indicating a hallmark of wound healing. On the basis of the findings and our previous work, we proposed an integrated parallel systems biology model.

[Analysis of A Pedigree with Hereditary Coagulation Factor â « Deficiency Caused by Compound Heterozygous Mutations].

OBJECTIVE: To analysis clinical phenotype and potential genetic cause of a family affected with hereditary coagulation factor Ⅻ deficiency. METHODS: The prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-Dimer (D-D), coagulation factor Ⅻ activity (FⅫ:C) and coagulation factor Ⅻ antigen (FⅫ:Ag) were determined for phenotype diagnosis of the proband and his family members(3 generations and 5 people). Targeted capture and whole exome sequencing were performed in peripheral blood sample of the proband. Possible disease-causing mutations of F12 gene were obtained and further confirmed by Sanger sequencing. The corresponding mutation sites of the family members were analyzed afterwards. The online bioinformatics software AutoPVS1 and Mutation Taster was used to predict the effects of mutation sites on protein function. RESULTS: The APTT of the proband was significantly prolonged, reaching 180.9s. FⅫ:C and FⅫ:Ag of the proband was significantly reduced to 0.8% and 4.17%, respectively. The results of whole exome sequencing displayed that there were compound heterozygous mutations in F12 gene of the proband, including the c.1261G＞T heterozygous nonsense mutation in exon 11 (causing p.Glu421*) and the c.251dupG heterozygous frameshift mutation in exon 4 (causing p.Trp85Metfs*53). Both mutations are loss of function mutations with very strong pathogenicity, leading to premature termination of the protein. AutoPVS1 and Mutation Taster software predicted both mutations as pathogenic mutations. The results of Sanger sequencing revealed that c.1261G＞T heterozygous mutation of the proband was inherited from his mother, for which his brother and his daughter were c.1261G＞T heterozygous carriers. Genotype-phenotype cosegregation was observed in this family. CONCLUSION: The c.1261G＞T heterozygous nonsense mutation in exon 11 and the c.251dupG heterozygous frameshift mutation in exon 4 of the F12 gene probably account for coagulation factor Ⅻ deficiency in this family. This study reports two novel pathogenic F12 mutations for the first time worldwide.

Intergenomic and epistatic interactions control free radical mediated pancreatic ß-cell damage.

Alloxan (AL)-generated Reactive Oxygen Species (ROS) selectively destroy insulin-producing pancreatic ß-cells. A previous genome-wide scan (GWS) using a cohort of 296 F2 hybrids between NOD (AL-sensitive) and ALR (AL-resistant) mice identified linkages contributing to ß-cell susceptibility or resistance to AL-induced diabetes on Chromosomes (Chr) 2, 3, 8, and a single nucleotide polymorphism in mt-Nd2 of the mitochondrial genome (mtDNA). AL treatment of congenic and consomic NOD mouse stocks confirmed resistance linked to both the mtDNA and the Chr 8 locus from ALR [NOD.mtALR.ALR-(D8Mit293-D8Mit137)]. To identify possible epistatic interactions, the GWS analysis was expanded to 678 F2 mice. ALR-derived diabetes-resistance linkages on Chr 8 as well as the mt-Nd2 a allele were confirmed and novel additional linkages on Chr 4, 5, 6, 7, and 13 were identified. Epistasis was observed between the linkages on Chr 8 and 2 and Chr 8 and 6. Furthermore, the mt-Nd2 genotype affected the epistatic interactions between Chr 8 and 2. These results demonstrate that a combination of nuclear-cytoplasmic genome interactions regulates ß-cell sensitivity to ROS-mediated ALD.

Epistasis contributes to the genetic buffering of plasma HDL cholesterol in mice.

Stressful environmental factors, such as a high-fat diet, can induce responses in the expression of genes that act to maintain physiological homeostasis. We observed variation in plasma concentrations of high-density lipoprotein (HDL) cholesterol across inbred mouse strains in response to high dietary fat intake. Several strains, including C57BL/6J, have stable levels of plasma HDL independent of diet, whereas other strains, including DBA2/J, show marked changes in plasma HDL. To explore this phenomenon further, we used publicly available data from a C57BL/6J × DBA/2J intercross to identify genetic factors that associate with HDL under high-fat diet conditions. Our analysis identified an epistatic interaction that plays a role in the buffering of HDL levels in C57BL/6J mice, and we have identified Arl4d as a candidate gene that mediates this effect. Structural modeling further elucidates the interaction of genetic factors that contribute to the robustness of HDL in response to high-fat diet in the C57BL/6J strain.

Plasma MIR-212-3p as a biomarker for acute right heart failure with pulmonary artery hypertension.

BACKGROUND: Acute right heart failure occurs in patients with pulmonary artery hypertension (PAH) with exposure to acute inflammation, the mortality rate is very high when right heart failure occurs. Biomarkers that can be used to detect acute right heart failure in patients with pulmonary hypertension need to be studied. METHODS: A PAH rat model was established using monocrotaline, and lipopolysaccharide was used to induce acute right heart failure. The Agilent rat miRNA microarray, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to assess the microRNA expression of PAH rats. The expression of up- and downregulated miRNAs in plasma from PAH patients with acute right heart failure was validated with quantitative reverse transcription polymerase chain reaction (qRT-PCR). Then, the Wilcoxon matched paired test and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: Thirty-three miRNAs were upregulated, and 7 miRNAs were downregulated in plasma of PAH rats with acute right heart failure. In the plasma of PAH patients, the miR-212-3p level was inversely correlated with the level of NT-pro BNP, and the area under the ROC curve was 0.751. CONCLUSIONS: These results suggest that the reduction of the expression of MIR-212-3p may be a biomarker for PAH patients with right heart dysfunction.

Genetic factors contributing to obesity and body weight can act through mechanisms affecting muscle weight, fat weight, or both.

Genetic loci for body weight and subphenotypes such as fat weight have been mapped repeatedly. However, the distinct effects of different loci and physiological interactions among different traits are often not accounted for in mapping studies. Here we used the method of structural equation modeling to identify the specific relationships between genetic loci and different phenotypes influencing body weight. Using this technique, we were able to distinguish genetic loci that affect adiposity from those that affect muscle growth. We examined the high body weight-selected mouse lines NMRI8 and DU6i and the intercross populations NMRI8 x DBA/2 and DU6i x DBA/2. Structural models help us understand whether genetic factors affect lean mass and fat mass pleiotropically or nonpleiotropically. Sex has direct effects on both fat and muscle weight but also influences fat weight indirectly via muscle weight. Three genetic loci identified in these two crosses showed exclusive effects on fat deposition, and five loci contributed exclusively to muscle weight. Two additional loci showed pleiotropic effects on fat and muscle weight, with one locus acting in both crosses. Fat weight and muscle weight were influenced by epistatic effects. We provide evidence that significant fat loci in strains selected for body weight contribute to fat weight both directly and indirectly via the influence on lean weight. These results shed new light on the action of genes in quantitative trait locus regions potentially influencing muscle and fat mass and thus controlling body weight as a composite trait.

Structural model analysis of multiple quantitative traits.

We introduce a method for the analysis of multilocus, multitrait genetic data that provides an intuitive and precise characterization of genetic architecture. We show that it is possible to infer the magnitude and direction of causal relationships among multiple correlated phenotypes and illustrate the technique using body composition and bone density data from mouse intercross populations. Using these techniques we are able to distinguish genetic loci that affect adiposity from those that affect overall body size and thus reveal a shortcoming of standardized measures such as body mass index that are widely used in obesity research. The identification of causal networks sheds light on the nature of genetic heterogeneity and pleiotropy in complex genetic systems.

Expression analysis of four pseudo-response regulator (PRR) genes in Chrysanthemum morifolium under different photoperiods.

Genes encoding pseudo-response regulator (PRR) proteins play significant roles in plant circadian clocks. In this study, four genes related to flowering time were isolated from Chrysanthemum morifolium. Phylogenetic analysis showed that they are highly homologous to the counterparts of PRRs of Helianthus annuus and named as CmPRR2, CmPRR7, CmPRR37, and CmPRR73. Conserved motifs prediction indicated that most of the closely related members in the phylogenetic tree share common protein sequence motifs, suggesting functional similarities among the PRR proteins within the same subtree. In order to explore functions of the genes, we selected two Chrysanthemum varieties for comparison; that is, a short-day sensitive Zijiao and a short-day insensitive Aoyunbaixue. Compared to Aoyunbaixue, Zijiao needs 13 more days to complete the flower bud differentiation. Evidence from spatio-temporal gene expression patterns demonstrated that the CmPRRs are highly expressed in flower and stem tissues, with a growing trend across the Chrysanthemum developmental process. In addition, we also characterized the CmPRRs expression patterns and found that CmPRRs can maintain their circadian oscillation features to some extent under different photoperiod treatment conditions. These lines of evidence indicated that the four CmPRRs undergo circadian oscillation and possibly play roles in regulating the flowering time of C. morifolium.

Over-Expression of ERF38 Gene Enhances Salt and Osmotic Tolerance in Transgenic Poplar.

Ethylene response factor (ERF) gene family plays an important role in abiotic stress responses. In this study, we isolated a salt-inducible ERF gene, ERF38 (Potri.006G138900.1), from the 84K poplar (Populus alba × Populus glandulosa) and investigated its functions in salt and osmotic tolerance. We identified that ERF38 protein was targeted to nucleus and had no self-activation. Results from yeast-one-hybrid indicated that the ERF38 protein can specifically bind to the dehydration responsive element (DRE). We then successfully transferred the ERF38 gene into the 84K poplar. Under respective salt and polyethylene glycol (PEG)-6000 stresses, four of the physiological traits, including peroxidase (POD) and superoxide dismutase (SOD) activities, soluble protein content, and proline content, increased significantly in the transgenic plants, compared to the wild type. Regarding the other two parameters, hydrogen peroxide (H2O2) and malondialdehyde (MDA) content, their increments in the transgenic lines under the stresses, which were compared to the water control, were significantly low than that of the wild type. In addition, reactive oxygen species (ROS) are scavenged in the transgenic lines under the stresses, but not in the wild type (WT). Interestingly, when challenged with the stresses, expression levels of a few genes associated with POD and SOD metabolism were significantly increased in the transgenic poplars. In all, evidence from morphological, physiological, and biochemical analyses indicated that over-expression of ERF38 gene can improve salt and osmotic tolerance in the transgenic poplar.

Comprehensive analysis of the three-amino-acid-loop-extension gene family and its tissue-differential expression in response to salt stress in poplar.

The three-amino-acid-loop-extension (TALE) transcription factor gene family is widely present in plants and plays an important role in its growth and development. However, studies on the gene family are limited in poplar. In this study, we investigated 35 TALE gene family members in terms of their evolutionary relationship, classification, physicochemical properties, gene structures, and protein motifs. We divided the genes into four classes, based on their protein sequences similarity. The members from each class share similar gene structures and motif compositions. Evidence from transcript profiling indicated that the majority of the TALE genes exhibited distinct expression patterns over leaf, stem, and root tissues. Out of the 35 genes, 17 genes are highly expressed in stems, suggesting that the TALE gene family may play an important role in secondary growth and wood formation. Furthermore, out of the 35 genes, 11 genes are responsive to salt stress, and the spatio-temporal expression patterns of these 11 genes under salt stress were analysed using RT-qPCR. Yeast two-hybridization analysis indicated that poplar TALE proteins from different classes can form heterodimers. These results lay the foundation for future studies on biological functions of poplar TALE genes.