Disruption of carotene biosynthesis leads to abnormal plastids and variegated leaves in Brassica napus.

Leaf color is an important characteristic of normal chloroplast development. Variegated plants have green- and white-sectored leaves, which can be used to identify important pathways and molecular mechanisms of chloroplast development. We studied two Brassica napus variegation mutants from same one variegated ancestor, designated ZY-4 and ZY-8, which have different degrees of variegation. When grown in identical conditions, the ratio of white sectors in ZY-4 leaves is higher than in ZY-8. In both mutants, the cells in green sectors contain normal chloroplasts; while, the cells in white sectors contain abnormal plastids. Seedling chloroplasts ultrastructure of both mutants showed that the biogenesis of chloroplasts was blocked in early stages; delayed development and structual damage in ZY-4 were more serious than in ZY-8. Employing bulked segregant analysis(BSA), two bulks (BY142 and BY137) from BC2F1 lines derived from ZY-4 and ZS11, and one bulk (BY56) from BC2F1 lines derived from ZY-8 and ZS11, and screening by Brassica 60K SNP BeadChip Array, showed the candidate regions localized in chromosome A08 (BY142), C04 (BY137), and A08 (BY56), respectively. Transcriptome analysis of five seedling development stages of ZY-4, ZY-8, and ZS11 showed that photosynthesis, energy metabolism-related pathways and translation-related pathways were important for chloroplast biogenesis. The number of down- or up-regulated genes related to immune system process in ZY-4 was more than in ZY-8. The retrograde signaling pathway was mis-regulated in both mutants. DEG analysis indicated that both mutants showed photooxidative damages. By coupling transcriptome and BSA CHIP analyses, some candidate genes were identified. The gene expression pattern of carotene biosynthesis pathway was disrupted in both mutants. However, histochemical analysis of ROS revealed that there was no excessive accumulation of ROS in ZY-4 and ZY-8. Taken together, our data indicate that the disruption of carotene biosynthetic pathways leads to the variegation phenotypes of ZY-4 and ZY-8 and there are some functions that can compensate for the disruption of carotene biosynthesis in ZY-4 and ZY-8 to reduce ROS and prevent seedling mortality.

Mitochondrial genome and transcriptome analysis of five alloplasmic male-sterile lines in Brassica juncea.

BACKGROUND: Alloplasmic lines, in which the nuclear genome is combined with wild cytoplasm, are often characterized by cytoplasmic male sterility (CMS), regardless of whether it was derived from sexual or somatic hybridization with wild relatives. In this study, we sequenced and analyzed the mitochondrial genomes of five such alloplasmic lines in Brassica juncea. RESULTS: The assembled and annotated mitochondrial genomes of the five alloplasmic lines were found to have virtually identical gene contents. They preserved most of the ancestral mitochondrial segments, and the same candidate male sterility gene (orf108) was found harbored in mitotype-specific sequences. We also detected promiscuous sequences of chloroplast origin that were conserved among plants of the Brassicaceae, and found the RNA editing profiles to vary across the five mitochondrial genomes. CONCLUSIONS: On the basis of our characterization of the genetic nature of five alloplasmic mitochondrial genomes, we speculated that the putative candidate male sterility gene orf108 may not be responsible for the CMS observed in Brassica oxyrrhina and Diplotaxis catholica. Furthermore, we propose the potential coincidence of CMS in alloplasmic lines. Our findings lay the foundation for further elucidation of male sterility gene.

Fine mapping of a silique length- and seed weight-related gene in Brassica napus.

KEY MESSAGE: Using microarray analysis combined with map-based cloning, a major locus positively regulating SL and SW was mapped to a 98.47 kb interval on A09 in rapeseed. In rapeseed, seed yield is closely associated with silique-related traits such as silique length (SL) and seed weight (SW). Previously identified quantitative trait loci (QTLs) revealed that SL and SW are complex traits and many QTLs overlap. However, the genetic characterization of the association between SL and SW is poorly understood. In the present study, a BC3F3 near isogenic line developed from a short silique plant and the long silique cultivar 'ZS11' was analyzed to identify the locus related to SL. Map-based cloning indicated that a major locus acting as a single Mendelian factor was mapped to a 98.47 kb region on chromosome A09. BLAST analysis and DNA sequencing showed SNP variations and a fragment replacement in the upstream region of the candidate gene BnaA09g55530D may alter gene expression and influence SL. The results showed that this SL locus may also positively affect SW as well as in the 186 rapeseed accessions identified by the associated markers. Therefore, selecting plants with appropriate SL and developing functional markers for the associated gene could play important roles in the molecular breeding of high-yield rapeseed varieties.

The effect of cigarette smoking on vitamin D level and depression in male patients with acute ischemic stroke.

OBJECTIVE: The association between low vitamin D levels and depression has been well documented in nonstroke subjects. Accumulating evidence shows that low vitamin D levels may be also associated with depression post stroke. Cigarette smoking was associated with lower vitamin D levels. The purposes of this study were to compare vitamin D levels in smokers to nonsmokers and examine the association between vitamin D levels and depression symptoms in patients with acute ischemic stroke. MATERIALS AND METHODS: Serum levels of 25-hydroxyvitamin D [25(OH)D] were measured in 194 males within 24h after admission: 116 smokers and 78 nonsmokers. Depression symptoms were assessed with the 17-item Hamilton Depression Scale (HAMD-17). Patients with the HAMD-17 score >7 were identified to have depression symptoms. RESULTS: The chi-square test showed that the frequency of depression in the smoker group was 23.3% (27/116), which was significantly higher than that in the nonsmoker group (11.5%=9/78), with an odds ratios (OR) of 2.33 (95% CI: 1.03-5.27; χ(2)=4.25, df=1, p=0.039, φ=0.15). Vitamin D levels were significantly lower in smokers than in nonsmokers (52.4±20.8 vs 61.7±19.2; F=9.88, p=0.002), with an effect size of 0.05 (ηp(2)). Patients with depression symptoms showed lower vitamin D levels than those with no depression symptoms (49.2±19.6 vs 57.7±20.6; F=5.03, p=0.03), with an effect size of 0.03 (ηp(2)). CONCLUSION: Higher rates of depression in smokers with acute ischemic stroke may be associated with lower vitamin D levels induced by smoking.

Coagulation-ultrafiltration integrated process for membrane fouling control: Influence of Al species and SUVA values of water.

Natural organic matter (NOM) pollution is a great challenge for the ultrafiltration (UF) process owing to the inevitable membrane fouling. In this study, three Al species coagulants (Ala/Alb/Alc) and their composites in combination with Poly dimethyl ammonium chloride (PolyDMDAAC) were used as a pretreatment strategy for the UF process. Then, test waters with different NOM fractions (i.e., humic acid, fulvic acid, protein, and polysaccharide) were prepared to analyze the effects of NOM characteristics on membrane fouling behaviors. The results indicated that compared with Alb and Alc, Ala showed higher removal efficiencies for hydrophobic NOM, aromatic organic matters, and suspended particles, but a limited effect on removing dissolved organic carbon (DOC). Ala or Ala-PolyDMDAAC effectively mitigated membrane fouling by removing the hydrophobic NOM in the coagulation process and forming the porous cake layer in the UF process. The test waters with higher specific ultraviolet absorbance (SUVA) resulted in more severe total and reversible membrane fouling but lighter irreversible fouling. After pretreatment by Ala or Ala-PolyDMDAAC, water samples with the medium SUVA value exhibited remarkable alleviation of membrane fouling due to the formation of large, compact, and robust flocs, as well as the construction of loose and poriferous cake layer on the membrane surface. Although hydrophilic NOM was challenging to be removed by coagulation, the interception and re-adsorption of porous cake layers contributed to the alleviation of irreversible fouling.

The silencing of DEK reduced disease resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 based on virus-induced gene silencing analysis in tomato.

DEK involves in the modulation of cell proliferation, differentiation, apoptosis, migration and cell senescence. However, direct genetic evidence proving the functions of DEK in disease resistance against pathogens is still deficient. In the present study, four DEKs were identified in tomato genome and their roles in disease resistance in tomato were analyzed. The expression levels of DEKs were differently induced by Botrytis cinerea, Pseudomonas syringae pv. tomato (Pst) DC3000 and defense-related signaling molecules (such as jasmonic acid, aethylene precursor and salicylic acid). The DEKs' silencing by virus induced gene silencing led to decreased resistance against B. cinerea or Pst DC3000. The underlying mechanisms may be through the upregulation of the accumulation of reactive oxygen species (ROS) and the changed expression levels of defense-related genes by pathogen inoculation. These results indicate that DEKs involve in disease resistance against different pathogens and thus broaden the knowledge of DEK genes' function in tomato.

Study on the metabolism toxicity, susceptibility and mechanism of di-(2-ethylhexyl) phthalate on rat liver BRL cells with insulin resistance in vitro.

Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizer which could be easily absorbed by humans and animals through various channels. It has been found that exposure to DEHP could increase the incidence of insulin resistance. In this study, therefore, the metabolism toxicity, susceptibility and mechanism of DEHP (5500 and 50,000 nM exposure for 24 h) on normal BRL cells (Buffalo Rat Liver cells) and BRL cells with insulin resistance induced by insulin were investigated. The results showed that DEHP could cause cell damage with ALT and AST activities and MDA levels increased, cell apoptosis with Caspase-3 levels increased and insulin resistance with IR-ß levels decreased in BRL cells with resistance and normal BRL cells. Western-blot analysis and Q-PCR showed that the levels and gene expressions of insulin signaling proteins (IRS-1, GLUT4, GSK-3α, GSK-3ß, PI3K, AKT, mTOR), cell signaling proteins (RAS, ERK1/2, MEK1/2, BAD, BAX, BCL-2) and immediate early genes in insulin resistance cells and normal cells were significantly altered by DEHP. DEHP significantly promoted serine phosphorylation of IRS-1. The insulin resistance cells in metabolism toxicity were more sensitive to DEHP than normal cells. Intervention with insulin could improve the metabolism toxicity and insulin resistance. The results indicated that DEHP exerted metabolic toxic effects and increased insulin resistance through interfering with glucose metabolism and insulin signaling transduction pathway. Moreover, the risks of DEHP-induced metabolic toxicity and insulin resistance in BRL cells with insulin resistance were higher than that of normal BRL cells.

Improvement of high-glucose and insulin resistance of chromium malate in 3T3-L1 adipocytes by glucose uptake and insulin sensitivity signaling pathways and its mechanism.

Previous study has revealed that chromium malate could improve insulin resistance and the regulation of fasting blood glucose in type 2 diabetic rats. This study was designed to investigate the effect of chromium malate on hypoglycemic and improve insulin resistance activities in 3T3-L1 adipocytes with insulin resistance and investigate the acting mechanism. The result indicated that chromium malate exhibited direct hypoglycemic activity in vitro. Compared with the model group, chromium malate could significantly promote the expression levels of GLUT-4, Akt, Irs-1, PPARγ, PI3K and p38-MAPK and their mRNA, increase p-AKT/AKT level, AKT and AMPKß1 phosphorylation and reduce Irs-1 phosphorylation and p-Irs-1/Irs-1 level in 3T3-L1 adipocytes (p < 0.05). Chromium malate is more effective in regulating the proteins and mRNA expressions than those of chromium trichloride and chromium picolinate. Compared to the model group, pretreatment with the specific p38-MAPK inhibitor completely inhibited the GLUT-4 and Irs-1 proteins and mRNA expressions induced by the chromium malate. In conclusion, chromium malate had a beneficial influence on improvement of controlling glucose levels and insulin resistance in 3T3-L1 adipocytes with insulin resistance by regulating proteins productions and genes expressions in glucose uptake and insulin sensitivity signaling pathways.

Low serum prealbumin levels in post-stroke depression.

Previous studies have shown that prealbumin is associated with depression. However, the association between prealbumin and post-stroke depression remains unelucidated. This observational cohort study determined whether low baseline serum prealbumin could predict post-stroke depression at 1 month in patients admitted with acute stroke. The study, conducted from October 2013 to September 2014, included 307 patients with acute stroke who were followed-up for 1 month. Serum prealbumin was measured within 24h after admission using an immunoturbidimetric method. The17-item Hamilton Depression Scale was used to evaluate depression symptoms. Patients with a depression score of ≥7 were evaluated using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for diagnosing post-stroke depression at 1 month. Binary logistic regression analysis was used to evaluate possible predictors of post-stroke depression. Overall, 93 (30.3%) patients were diagnosed with post-stroke depression. Serum prealbumin was significantly lower in patients with versus those without post-stroke depression, and was a significant predictor of post-stroke depression after adjusting for confounding risk factors. In conclusion, baseline serum prealbumin level was associated with post-stroke depression at 1 month, suggesting that prealbumin might be a useful biomarker for post-stroke depression.

The association between serum ferritin levels and post-stroke depression.

BACKGROUND: Post-stroke depression (PSD) is a common neuropsychiatric affective disorder occurring after stroke. Elevated serum ferritin levels have been reported to contribute to depression. Our aim was to determine whether there is a relationship between serum ferritin levels and PSD. METHODS: 196 ischemic stroke patients were consecutively recruited within the first 24h of stroke onset and were followed up for 2 months. Serum ferritin levels were assayed by electrochemiluminescence immunoassay at hospital admission. Clinical depression was diagnosed according to DSM-IV criteria and a HAMD -17 score of ≥ 7. Meanwhile, 100 normal control subjects were also recruited. RESULTS: We found that 56 stroke patients (28.6%) were diagnosed with PSD at two months. There was a significant intergroup difference in serum ferritin levels within 24h after admission (F=25.044, P<0.001). Serum ferritin levels were significantly higher at admission in PSD patients than in non-PSD patients and normal controls. There was a positive correlation between serum ferritin levels and hs-CRP at admission in PSD patients (r=0.129, P=0.042). In multivariate analyses, serum levels of ferritin ≥ 130.15 µg/L were independently associated with PSD at two months [odds ratio OR=5.388, 95%CI:1.725-16.829; P=0.004] after adjusting for all possible variables. LIMITATIONS: We excluded patients with severe aphasia and with serious conditions.In addition, the information for dietary intake was not recorded, which may influence body iron stores. CONCLUSION: Our findings show that elevated serum ferritin levels at admission are associated with PSD and may predict its development at 2 months post-stroke.

Low Serum Levels of Uric Acid are Associated With Development of Poststroke Depression.

Poststroke depression (PSD) is a frequent complication of stroke that has been associated with poorer outcome of stroke patients. This study sought to examine the possible association between serum uric acid levels and the development of PSD.We recruited 196 patients with acute ischemic stroke and 100 healthy volunteers. Serum uric acid levels were tested by uricase-PAP method within 24 hr after admission. Neuropsychological evaluations were conducted at 3-month poststroke. The 17-item Hamilton Depression Scale was used to assess depressive symptoms. Diagnosis of PSD was made in accordance with DSM-IV criteria for depression. Multivariate analyses were conducted using logistic regression models.Fifty-six patients (28.6%) were diagnosed as having PSD at 3 months. PSD patients showed significantly lower levels of uric acid at baseline as compared to non-PSD patients (237.02 ±â€Š43.43 vs 309.10 ±â€Š67.44 µmol/L, t = -8.86, P < 0.001). In multivariate analyses, uric acid levels (≤239.0 and ≥328.1 µmol/L) were independently associated with the development of PSD (OR, 7.76; 95% confidence interval [CI], 2.56-23.47, P < 0.001 and OR, 0.05; 95% CI, 0.01-0.43, P = 0.01, respectively) after adjustment for possible variables.Serum uric acid levels at admission are found to be correlated with PSD and may predict its development at 3 months after stroke.