CG hypermethylation of the bHLH39 promoter regulates its expression and Fe deficiency responses in tomato roots

Iron(Fe)is an essential micronutrient for all organisms,including plants,whose limited bioavailability restricts plant growth,yield,and nutritional quality.While the transcriptional regulation of plant responses to Fe deficiency have been extensively studied,the contribution of epigenetic modulations,such as DNA methylation,remains poorly understood.Here,we report that treatment with a DNA methylase inhibitor repressed Fe deficiency-induced responses in tomato(Solanum lycopersicum)roots,suggesting the importance of DNA methylation in regulating Fe deficiency responses.Dynamic changes in the DNA methylome in tomato roots responding to short-term(12 hours)and long-term(72 hours)Fe deficiency identified many differentially methylated regions(DMRs)and DMR-associated genes.Most DMRs occurred at CHH sites under short-term Fe deficiency,whereas they were predominant at CG sites following long-term Fe deficiency.Furthermore,no correlation was detected between the changes in DNA methylation levels and the changes in transcript levels of the affected genes under either short-term or long-term treatments.Notably,one exception was CG hypermethylation at the bHLH39 promoter,which was positively correlated with its transcriptional induction.In agreement,we detected lower CG methylation at the bHLH39 promoter and lower bHLH39 expression in MET1-RNA interference lines compared with wild-type seedlings.Virus-induced gene silencing of bHLH39 and luciferase reporter assays revealed that bHLH39 is positively involved in the modulation of Fe homeostasis.Altogether,we propose that dynamic epigenetic DNA methylation in the CG context at the bHLH39 promoter is involved in its transcriptional regulation,thus contributing to the Fe deficiency response of tomato.

Photosynthetic features of leaf and silique of 'Qinyou 7' oilseed rape(Brassica napus L.) at reproductive growth stage

Photosynthetic products are mainly produced by leaf and green silique of oilseed rape(Brassica napus L.) at reproductive growth stage. This study aimed to compare photosynthetic features of leaf and green silique of 'Qinyou 7' hybrid oilseed rape variety. Results showed that, during photosynthetic day time, net photosynthetic rate(P_N) and stomatal conductance(gs) of leaf were markedly higher than that of silique. Compared with silique, leaf had significant higher P_N, g_s, light saturated net photosynthetic rate(P_(Nmax)), light saturation point(LSP), and apparent quantum yield(AQY), but lower light compensation point(LCP), CO_2 compensation point(Γ) and carboxylation efficiency(CE) under various light densities and CO_2 concentrations. Carboxylation activities of ribulose-1, 5-bisphosphate carboxylase/oxygenase(Rubisco), phosphoenolpyruvate carboxylase(PEPC) and chlorophyll a, b(Chl a, b) of leaf were significantly higher than that of silique shell. Our study demonstrated that leaf of oilseed rape at reproductive growth stage had higher photosynthetic capacity than green silique due to its higher carboxylation activity of photosynthetic enzymes as well as higher gs and Chl contents. This study might have good implication in selecting a biological control strategy to enhance seed yield and oil production of oilseed rape.

Effects of basic fibroblast growth factor on angiogenin expression and cell proliferation in H7402 human hepatoma cells

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Basic fibroblast growth factor (bFGF), which is highly expressed in developing tissues and malignant cells, regulates cell growth, differentiation, and migration. Its expression is essential for the progression and metastasis of HCC. This study aims to investigate the effects of bFGF on the expression of angiogenin, another growth factor, which plays an important role in tumor angiogenesis, and on cell proliferation in H7402 human hepatoma cells. The bFGF sense cDNA or antisense cDNA was stably transfected into H7402 cells. Genomic DNA PCR analysis demonstrated that human bFGF sense cDNA or antisense cDNA was inserted into the genome. Furthermore, the expression of bFGF and angiogenin was examined by RT-PCR and Western blot assays. MTT and colony formation assays were employed to determine cell proliferation. Stable bFGF over-expressing and under-expressing transfectants were successfully established. Expression of angiogenin was decreased in the over-expressing bFGF cells (sense transfectants) and was increased in the under-expressing bFGF cells (antisense transfectants). Cell proliferation increased in the bFGF sense transfectants and decreased in the bFGF antisense transfectants. These results demonstrated that the endogenous bFGF may not only negatively regulate the angiogenin expression but also contribute to the overall cell proliferation in H7402 human hepatoma cells. This study may be helpful in finding a potential therapeutic approach to HCC.

Testing the role of genetic variation of the MC4R gene in Chinese population in antipsychotic-induced metabolic disturbance

Antipsychotic-induced metabolic disturbance(AIMD) is a common adverse effect of antipsychotics with genetics partly underpinning variation in susceptibility among schizophrenia patients. Melanocortin4 receptor(MC4 R) gene, one of the candidate genes for AIMD, has been under-studied in the Chinese patients. We conducted a pharmacogenetic study in a large cohort of Chinese patients with schizophrenia. In this study, we investigated the genetic variation of MC4 R in Chinese population by genotyping two SNPs(rs489693 and rs17782313) in 1,991 Chinese patients and examined association of these variants with the metabolic effects that were often observed to be related to AIMD. Metabolic measures, including body mass index(BMI), waist circumference(WC), glucose, triglyceride, high-density lipoprotein(HDL), and low-density lipoprotein(LDL) levels were assessed at baseline and after 6-week antipsychotic treatment. We found that interaction of SNP×medication status(drug-na?ve/medicated) was significantly associated with BMI, WC, and HDL change %, respectively. Both SNPs were significantly associated with baseline BMI and WC in the medicated group. Moderate association of rs489693 with WC, Triglyceride, and HDL change % were observed in the whole sample. In the drug-na?ve group, we found recessive effects of rs489693 on BMI gain more than 7%, WC and Triglyceride change %, with AA incurring more metabolic adverse effects. In conclusion, the association between rs489693 and the metabolic measures is ubiquitous but moderate. Rs17782313 is less involved in AIMD. Two SNPs confer risk of AIMD to patients treated with different antipsychotics in a similar way.

Interaction Between Variations in Dopamine D2 and Serotonin 2A Receptor is Associated with Short-Term Response to Antipsychotics in Schizophrenia

Dear Editor,Schizophrenia is a chronic and debilitating brain disorder,which has a strong genetic component with heritability ranging from 66%to 85%[1,2].Currently,antipsychotic drugs remain the most effective treatment for the psychotic symptoms of schizophrenia[3].Because of the severe sideeffects of first-generation antipsychotics(FGAs),secondgeneration antipsychotics(SGAs)have become more widely used in the treatment of schizophrenia.

The miR157-SPL-CNR module acts upstream of bHLH101 to negatively regulate iron deficiency responses in tomato

Iron(Fe)homeostasis is critical for plant growth,development,and stress responses.Fe levels are tightly controlled by intricate regulatory networks in which transcription factors(TFs)play a central role.A series of basic helix-loop-helix(b HLH)TFs have been shown to contribute to Fe homeostasis,but the regulatory layers beyond b HLH TFs remain largely unclear.Here,we demonstrate that the SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE(SPL)TF Sl SPL-CNR negatively regulates Fe-deficiency responses in tomato(Solanum lycopersicum)roots.Fe deficiency rapidly repressed the expression of Sl SPL-CNR,and Fe deficiency responses were intensified in two clustered regularly interspaced palindromic repeats(CRISPR)/CRISPRassociated protein 9-generated Sl SPL-CNR knockout lines compared to the wild-type.Comparative transcriptome analysis identified 47 Fe deficiencyresponsive genes the expression of which is negatively regulated by Sl SPL-CNR,one of which,Slb HLH101,helps regulate Fe uptake genes.Sl SPLCNR localizes the nucleus and interacts with the GTAC and BOX 4(ATTAAT)motifs in the Slb HLH101 promoter to repress its expression.Inhibition of Sl SPL-CNR expression in response to Fe deficiency was well correlated with the expression of the micro RNA Slymi R157.Slymi R157-overexpressing tomato lines displayed enhanced Fe deficiency responses,as did Sl SPL-CNR loss-of-function mutants.We propose that the Slymi R157-Sl SPL-CNR module represents a novel pathway that acts upstream of Slb HLH101 to regulate Fe homeostasis in tomato roots.

Whole-milk consumption decreases the risk of inflammatory bowel disease:a two-sample Mendelian rand omization analysis

Objective: The impact of dairy fat on inflammatory bowel disease remained inconclusive. We aimed to compare the effects of whole-milk and skimmed-milk consumption on the risk of inflammatory bowel disease using a Mendelian randomization analysis.Methods: We conducted a genome-wide association study of the preference for whole versus skimmed milk using data for 20,200 whole-milk consumers and 67,847 skimmed-milk consumers from the UK Biobank. The lead single nucleotide polymorphisms in the associated loci were identified at the genome-wide significance level, and were further employed as instrumental variables for whole-milk preference. We conducted a two-sample Mendelian randomization analysis with whole-milk preference as the exposure and inflammatory bowel disease as the outcome. The pleiotropic effects and heterogeneity of the instrumental variables were estimated using Mendelian randomization-Egger regression and CochranQ test, respectively. This study was conducted using the UKB resources under the application "53536" . The UK Biobank was approved by the North West Multi-center Research Ethics Committee, the National Information Governance Board for Health and Social Care in England and Wales, and the Community Health Index Advisory Group in Scotland.Results: The genome-wide association study identified five lead nucleotide polymorphisms associated with whole-milk preference. Mendelian randomization indicated that whole-milk preference significantly decreased the risk of inflammatory bowel disease (β=-1.735,P=0.048). Of the two subtypes, whole-milk preference was associated with a lower risk of Crohn disease (β=-2.549,P=0.032), but had no significant effect on the risk of ulcerative colitis (β=-1.002,P=0.44).Conclusion: Consumption of whole-milk fat may protect against Crohn disease, compared with skimmed milk. This conclusion was based on causal inference in a cohort study, and further validation in randomized controlled trials is warranted.