scholarly journals Integrated Transcriptome Analysis and Single-Base Resolution Methylomes of Watermelon (Citrullus lanatus) Reveal Epigenome Modifications in Response to Osmotic Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangming Zhu ◽  
Mingyan Li ◽  
Manwen Yan ◽  
Fei Qiao ◽  
Xuefei Jiang

DNA methylation plays an important role against adverse environment by reshaping transcriptional profile in plants. To better understand the molecular mechanisms of watermelon response to osmotic stress, the suspension cultured watermelon cells were treated with 100mM mannitol, and then a methylated cytosines map was generated by whole genome bisulfite sequencing (WGBS). Combined with transcriptome sequencing, the effects of osmotic stress on differentially methylated expressed genes (DMEGs) were assessed. It was found that genes related to plant hormone synthesis, signal transduction, osmoregulatory substance-related and reactive oxygen species scavenging-related enzyme could rapidly respond to osmotic stress. The overall methylation level of watermelon decreased after osmotic stress treatment, and demethylation occurred in CG, CHG, and CHH contexts. Moreover, differentially methylated expressed genes (DMEGs) were significantly enriched in RNA transport, starch and sucrose metabolism, plant hormone signal transduction and biosynthesis of secondary metabolites, especially in biosynthesis of osmolytes synthase genes. Interestingly, demethylation of a key enzyme gene Cla014489 in biosynthesis of inositol upregulated its expression and promoted accumulation of inositol, which could alleviate the inhibition of cell growth caused by osmotic stress. Meanwhile, a recombinant plasmid pET28a-Cla014489 was constructed and transferred into Escherichia coli BL21 for prokaryotic expression and the expression of ClMIPS protein could improve the tolerance of E. coli to osmotic stress. The effect of methylation level on the expression properties of inositol and its related genes was further confirmed by application of DNA methylation inhibitor 5-azacytidine. These results provide a preliminary insight into the altered methylation levels of watermelon cells in response to osmotic stress and suggest a new mechanism that how watermelon cells adapt to osmotic stress.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Xiaofeng Zhou ◽  
Yingting He ◽  
Nian Li ◽  
Guofeng Bai ◽  
Xiangchun Pan ◽  
...  

AbstractIn female mammals, the proliferation, apoptosis, and estradiol-17β (E2) secretion of granulosa cells (GCs) have come to decide the fate of follicles. DNA methylation and RSPO2 gene of Wnt signaling pathway have been reported to involve in the survival of GCs and follicular development. However, the molecular mechanisms for how DNA methylation regulates the expression of RSPO2 and participates in the follicular development are not clear. In this study, we found that the mRNA and protein levels of RSPO2 significantly increased during follicular development, but the DNA methylation level of RSPO2 promoter decreased gradually. Inhibition of DNA methylation or DNMT1 knockdown could decrease the methylation level of CpG island (CGI) in RSPO2 promoter and upregulate the expression level of RSPO2 in porcine GCs. The hypomethylation of −758/−749 and −563/−553 regions in RSPO2 promoter facilitated the occupancy of transcription factor E2F1 and promoted the transcriptional activity of RSPO2. Moreover, RSPO2 promoted the proliferation of GCs with increasing the expression level of PCNA, CDK1, and CCND1 and promoted the E2 secretion of GCs with increasing the expression level of CYP19A1 and HSD17B1 and inhibited the apoptosis of GCs with decreasing the expression level of Caspase3, cleaved Caspase3, cleaved Caspase8, cleaved Caspase9, cleaved PARP, and BAX. In addition, RSPO2 knockdown promoted the apoptosis of GCs, blocked the development of follicles, and delayed the onset of puberty with decreasing the expression level of Wnt signaling pathway-related genes (LGR4 and CTNNB1) in vivo. Taken together, the hypomethylation of −758/−749 and −563/−553 regions in RSPO2 promoter facilitated the occupancy of E2F1 and enhanced the transcription of RSPO2, which further promoted the proliferation and E2 secretion of GCs, inhibited the apoptosis of GCs, and ultimately ameliorated the development of follicles through Wnt signaling pathway. This study will provide useful information for further exploration on DNA-methylation-mediated RSPO2 pathway during follicular development.



2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Roberta Magnano San Lio ◽  
Giuliana Favara ◽  
Claudia La Mastra ◽  
...  

Uncovering the relationship between body mass index (BMI) and DNA methylation could be useful to understand molecular mechanisms underpinning the effects of obesity. Here, we presented a cross-sectional study, aiming to evaluate the association of BMI and obesity with long interspersed nuclear elements (LINE-1) methylation, among 488 women from Catania, Italy. LINE-1 methylation was assessed in leukocyte DNA by pyrosequencing. We found a negative association between BMI and LINE-1 methylation level in both the unadjusted and adjusted linear regression models. Accordingly, obese women exhibited lower LINE-1 methylation level than their normal weight counterpart. This association was confirmed after adjusting for the effect of age, educational level, employment status, marital status, parity, menopause, and smoking status. Our findings were in line with previous evidence and encouraged further research to investigate the potential role of DNA methylation markers in the management of obesity.



2018 ◽  
Vol 13 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Xiaowu Chen ◽  
Yonghua Zhao ◽  
Yudong He ◽  
Jinliang Zhao

AbstractSkewed sex development is prevalent in fish hybrids. However, the histological observation and molecular mechanisms remain elusive. In this study, we showed that the interspecific hybrids of the two fish species, Oreochromis niloticus and Oreochromis aureus, had a male ratio of 98.02%. Microscopic examination revealed that the gonads of both male and female hybrids were developmentally retarded. Compared with the ovaries, the testes of both O. niloticus and hybrids showed higher DNA methylation level in two selected regions in the promoter of cyp19a, the gonadal aromatase gene that converts androgens into estrogens, cyp19a showed higher level gene expression in the ovary than in the testis in both O. niloticus and hybrid tilapia. Methylation and gene expression level of cyp19a were negative correlation between the testis and ovary. Gene transcription was suppressed by the methylation of the cyp19a promoter in vitro. While there is no obvious difference of the methylation level in testis or ovary between O. niloticus and hybrids. Thus, the DNA methylation of the promoter of cyp19a may be an essential component of the sex maintenance, but not a determinant of high male ratio and developmental retardation of gonads in tilapia hybrids.



2021 ◽  
Author(s):  
Roxane Verdikt ◽  
Sophie Bouchat ◽  
Alexander O. Pasternak ◽  
Lorena Nestola ◽  
Gilles Darcis ◽  
...  

The multiplicity, heterogeneity and dynamic nature of HIV-1 latency mechanisms are reflected in the current lack of functional cure for HIV-1 and in the various reported ex vivo potencies of latency-reversing agents. Here, we investigated the molecular mechanisms underlying the potency of the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-AzadC) in HIV-1 latency reversal. Doing so, we uncovered specific demethylation CpG signatures induced by 5-AzadC in the HIV-1 promoter. By analyzing the binding modalities to these CpG, we revealed the recruitment of the epigenetic integrator UHRF1 to the HIV-1 promoter. We further demonstrated the role of UHRF1 in DNA methylation-mediated silencing of the latent HIV-1 promoter. As a proof-of-concept to this molecular characterization, we showed that pharmacological downregulation of UHRF1 in ex vivo HIV+ patient cell cultures resulted in potent reactivation of latent HIV-1. Together, we identify UHRF1 as a novel actor in HIV-1 gene silencing and highlight that it constitutes a new molecular target for HIV-1 curative strategies.



2019 ◽  
Vol 20 (24) ◽  
pp. 6138 ◽  
Author(s):  
Mbuya Sylvain Ntambo ◽  
Jian-Yu Meng ◽  
Philippe C. Rott ◽  
Robert J. Henry ◽  
Hui-Li Zhang ◽  
...  

Sugarcane (Saccharum spp. hybrids) is a major source of sugar and renewable bioenergy crop worldwide and suffers serious yield losses due to many pathogen infections. Leaf scald caused by Xanthomonas albilineans is a major bacterial disease of sugarcane in most sugarcane-planting countries. The molecular mechanisms of resistance to leaf scald in this plant are, however, still unclear. We performed a comparative transcriptome analysis between resistant (LCP 85-384) and susceptible (ROC20) sugarcane cultivars infected by X. albilineans using the RNA-seq platform. 24 cDNA libraries were generated with RNA isolated at four time points (0, 24, 48, and 72 h post inoculation) from the two cultivars with three biological replicates. A total of 105,783 differentially expressed genes (DEGs) were identified in both cultivars and the most upregulated and downregulated DEGs were annotated for the processes of the metabolic and single-organism categories, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the 7612 DEGs showed that plant–pathogen interaction, spliceosome, glutathione metabolism, protein processing in endoplasmic reticulum, and plant hormone signal transduction contributed to sugarcane’s response to X. albilineans infection. Subsequently, relative expression levels of ten DEGs determined by quantitative reverse transcription-PCR (qRT-PCR), in addition to RNA-Seq data, indicated that different plant hormone (auxin and ethylene) signal transduction pathways play essential roles in sugarcane infected by X. albilineans. In conclusion, our results provide, for the first time, valuable information regarding the transcriptome changes in sugarcane in response to infection by X. albilineans, which contribute to the understanding of the molecular mechanisms underlying the interactions between sugarcane and this pathogen and provide important clues for further characterization of leaf scald resistance in sugarcane.



2021 ◽  
Author(s):  
Xingbo Bian ◽  
Yan Zhao ◽  
Shengyuan Xiao ◽  
He Yang ◽  
Yongzhong Han ◽  
...  

Abstract Background: Ginseng rusty root symptoms (GRS) is one of the primary diseases of ginseng. It leads to a severe decline in the quality of ginseng. Results: Compared with Healthy ginseng (HG), 949 metabolites and 9451 genes in diseased tissues were significantly changed at the metabolic and transcription levels. The metabolic patterns of the diseased tissues changed significantly, and organic acids, alkaloids, alcohols, and phenols may play a vital role in the response of ginseng to this disease. There were significant differences in the expression of plant hormone signal transduction, phenylpropanoid biosynthesis, peroxidase pathway, and multiple genes in the plant-pathogen interaction pathway.Conclusion: The current study performed a comparative metabolome and transcriptome analysis of GRS and HG. Based on the findings at the transcriptional and metabolic levels, the mechanism model of ginseng response to rusty root symptoms was established. Our results provide new insights into ginseng's response to rusty root symptoms, which will help reveal the potential molecular mechanisms of this disease in ginseng.



2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaochun Wei ◽  
Md. Abdur Rahim ◽  
Yanyan Zhao ◽  
Shuangjuan Yang ◽  
Zhiyong Wang ◽  
...  

Chinese cabbage is one of the most important and widely consumed vegetables in China. The developmental transition from the vegetative to reproductive phase is a crucial process in the life cycle of flowering plants. In spring-sown Chinese cabbage, late bolting is desirable over early bolting. In this study, we analyzed double haploid (DH) lines of late bolting (“Y410-1” and “SY2004”) heading Chinese cabbage (Brassica rapa var. pekinensis) and early-bolting Chinese cabbage (“CX14-1”) (B. rapa ssp. chinensis var. parachinensis) by comparative transcriptome profiling using the Illumina RNA-seq platform. We assembled 721.49 million clean high-quality paired-end reads into 47,363 transcripts and 47,363 genes, including 3,144 novel unigenes. There were 12,932, 4,732, and 4,732 differentially expressed genes (DEGs) in pairwise comparisons of Y410-1 vs. CX14-1, SY2004 vs. CX14-1, and Y410-1 vs. SY2004, respectively. The RNA-seq results were confirmed by reverse transcription quantitative real-time PCR (RT-qPCR). A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs revealed significant enrichment for plant hormone and signal transduction as well as starch and sucrose metabolism pathways. Among DEGs related to plant hormone and signal transduction, six unigenes encoding the indole-3-acetic acid-induced protein ARG7 (BraA02g009130), auxin-responsive protein SAUR41 (BraA09g058230), serine/threonine-protein kinase BSK11 (BraA07g032960), auxin-induced protein 15A (BraA10g019860), and abscisic acid receptor PYR1 (BraA08g012630 and BraA01g009450), were upregulated in both late bolting Chinese cabbage lines (Y410-1 and SY2004) and were identified as putative candidates for the trait. These results improve our understanding of the molecular mechanisms underlying flowering in Chinese cabbage and provide a foundation for studies of this key trait in related species.



2020 ◽  
Vol 27 (2) ◽  
pp. 187-215 ◽  
Author(s):  
Lavinia Raimondi ◽  
Angela De Luca ◽  
Gianluca Giavaresi ◽  
Agnese Barone ◽  
Pierosandro Tagliaferri ◽  
...  

: Chemoprevention is based on the use of non-toxic, pharmacologically active agents to prevent tumor progression. In this regard, natural dietary agents have been described by the most recent literature as promising tools for controlling onset and progression of malignancies. Extensive research has been so far performed to shed light on the effects of natural products on tumor growth and survival, disclosing the most relevant signal transduction pathways targeted by such compounds. Overall, anti-inflammatory, anti-oxidant and cytotoxic effects of dietary agents on tumor cells are supported either by results from epidemiological or animal studies and even by clinical trials. : Multiple myeloma is a hematologic malignancy characterized by abnormal proliferation of bone marrow plasma cells and subsequent hypercalcemia, renal dysfunction, anemia, or bone disease, which remains incurable despite novel emerging therapeutic strategies. Notably, increasing evidence supports the capability of dietary natural compounds to antagonize multiple myeloma growth in preclinical models of the disease, underscoring their potential as candidate anti-cancer agents. : In this review, we aim at summarizing findings on the anti-tumor activity of dietary natural products, focusing on their molecular mechanisms, which include inhibition of oncogenic signal transduction pathways and/or epigenetic modulating effects, along with their potential clinical applications against multiple myeloma and its related bone disease.



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