scholarly journals Epigenetic Changes and Transcriptional Reprogramming Upon Woody Plant Grafting for Crop Sustainability in a Changing Environment

2021 ◽  
Vol 11 ◽  
Author(s):  
Aliki Kapazoglou ◽  
Eleni Tani ◽  
Evangelia V. Avramidou ◽  
Eleni M. Abraham ◽  
Maria Gerakari ◽  
...  

Plant grafting is an ancient agricultural practice widely employed in crops such as woody fruit trees, grapes, and vegetables, in order to improve plant performance. Successful grafting requires the interaction of compatible scion and rootstock genotypes. This involves an intricate network of molecular mechanisms operating at the graft junction and associated with the development and the physiology of the scion, ultimately leading to improved agricultural characteristics such as fruit quality and increased tolerance/resistance to abiotic and biotic factors. Bidirectional transfer of molecular signals such as hormones, nutrients, proteins, and nucleic acids from the rootstock to the scion and vice versa have been well documented. In recent years, studies on rootstock-scion interactions have proposed the existence of an epigenetic component in grafting reactions. Epigenetic changes such as DNA methylation, histone modification, and the action of small RNA molecules are known to modulate chromatin architecture, leading to gene expression changes and impacting cellular function. Mobile small RNAs (siRNAs) migrating across the graft union from the rootstock to the scion and vice versa mediate modifications in the DNA methylation pattern of the recipient partner, leading to altered chromatin structure and transcriptional reprogramming. Moreover, graft-induced DNA methylation changes and gene expression shifts in the scion have been associated with variations in graft performance. If these changes are heritable they can lead to stably altered phenotypes and affect important agricultural traits, making grafting an alternative to breeding for the production of superior plants with improved traits. However, most reviews on the molecular mechanisms underlying this process comprise studies related to vegetable grafting. In this review we will provide a comprehensive presentation of the current knowledge on the epigenetic changes and transcriptional reprogramming associated with the rootstock–scion interaction focusing on woody plant species, including the recent findings arising from the employment of advanced—omics technologies as well as transgrafting methodologies and their potential exploitation for generating superior quality grafts in woody species. Furthermore, will discuss graft—induced heritable epigenetic changes leading to novel plant phenotypes and their implication to woody crop improvement for yield, quality, and stress resilience, within the context of climate change.

2017 ◽  
Vol 114 (17) ◽  
pp. 4543-4548 ◽  
Author(s):  
Marianna Nagymihály ◽  
Alaguraj Veluchamy ◽  
Zoltán Györgypál ◽  
Federico Ariel ◽  
Teddy Jégu ◽  
...  

The formation of symbiotic nodule cells in Medicago truncatula is driven by successive endoreduplication cycles and transcriptional reprogramming in different temporal waves including the activation of more than 600 cysteine-rich NCR genes expressed only in nodules. We show here that the transcriptional waves correlate with growing ploidy levels and have investigated how the epigenome changes during endoreduplication cycles. Differential DNA methylation was found in only a small subset of symbiotic nodule-specific genes, including more than half of the NCR genes, whereas in most genes DNA methylation was unaffected by the ploidy levels and was independent of the genes’ active or repressed state. On the other hand, expression of nodule-specific genes correlated with ploidy-dependent opening of the chromatin as well as, in a subset of tested genes, with reduced H3K27me3 levels combined with enhanced H3K9ac levels. Our results suggest that endoreduplication-dependent epigenetic changes contribute to transcriptional reprogramming in the differentiation of symbiotic cells.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Federico Tinarelli ◽  
Elena Ivanova ◽  
Ilaria Colombi ◽  
Erica Barini ◽  
Edoardo Balzani ◽  
...  

Abstract Background DNA methylation has emerged as an important epigenetic regulator of brain processes, including circadian rhythms. However, how DNA methylation intervenes between environmental signals, such as light entrainment, and the transcriptional and translational molecular mechanisms of the cellular clock is currently unknown. Here, we studied the after-hours mice, which have a point mutation in the Fbxl3 gene and a lengthened circadian period. Methods In this study, we used a combination of in vivo, ex vivo and in vitro approaches. We measured retinal responses in Afh animals and we have run reduced representation bisulphite sequencing (RRBS), pyrosequencing and gene expression analysis in a variety of brain tissues ex vivo. In vitro, we used primary neuronal cultures combined to micro electrode array (MEA) technology and gene expression. Results We observed functional impairments in mutant neuronal networks, and a reduction in the retinal responses to light-dependent stimuli. We detected abnormalities in the expression of photoreceptive melanopsin (OPN4). Furthermore, we identified alterations in the DNA methylation pathways throughout the retinohypothalamic tract terminals and links between the transcription factor Rev-Erbα and Fbxl3. Conclusions The results of this study, primarily represent a contribution towards an understanding of electrophysiological and molecular phenotypic responses to external stimuli in the Afh model. Moreover, as DNA methylation has recently emerged as a new regulator of neuronal networks with important consequences for circadian behaviour, we discuss the impact of the Afh mutation on the epigenetic landscape of circadian biology.


2019 ◽  
Author(s):  
Patrick J Murphy ◽  
Jingtao Guo ◽  
Timothy G Jenkins ◽  
Emma R James ◽  
John R Hoidal ◽  
...  

SUMMARYPaternal cigarette smoke (CS) exposure is associated with increased risk of behavioral disorders and cancer in offspring, but the mechanism has not been identified. This study used mouse models to evaluate: 1) what impact paternal CS exposure has on sperm DNA methylation (DNAme), 2) whether sperm DNAme changes persist after CS exposure ends, 3) the degree to which DNAme and gene expression changes occur in offspring and 4) the mechanism underlying impacts of CS exposure. We demonstrate that CS exposure induces sperm DNAme changes that are partially corrected within 28 days of removal from CS exposure. Additionally, paternal smoking causes changes in neural DNAme and gene expression in offspring. Remarkably, the effects of CS exposure are largely recapitulated in oxidative stress-compromised Nrf2-/- mice and their offspring, independent of paternal smoking. These results demonstrate that paternal CS exposure impacts offspring phenotype and that oxidative stress underlies CS induced heritable epigenetic changes.


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.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Silvana C. E. Maas ◽  
Michelle M. J. Mens ◽  
Brigitte Kühnel ◽  
Joyce B. J. van Meurs ◽  
André G. Uitterlinden ◽  
...  

Abstract Background Tobacco smoking is a well-known modifiable risk factor for many chronic diseases, including cardiovascular disease (CVD). One of the proposed underlying mechanism linking smoking to disease is via epigenetic modifications, which could affect the expression of disease-associated genes. Here, we conducted a three-way association study to identify the relationship between smoking-related changes in DNA methylation and gene expression and their associations with cardio-metabolic traits. Results We selected 2549 CpG sites and 443 gene expression probes associated with current versus never smokers, from the largest epigenome-wide association study and transcriptome-wide association study to date. We examined three-way associations, including CpG versus gene expression, cardio-metabolic trait versus CpG, and cardio-metabolic trait versus gene expression, in the Rotterdam study. Subsequently, we replicated our findings in The Cooperative Health Research in the Region of Augsburg (KORA) study. After correction for multiple testing, we identified both cis- and trans-expression quantitative trait methylation (eQTM) associations in blood. Specifically, we found 1224 smoking-related CpGs associated with at least one of the 443 gene expression probes, and 200 smoking-related gene expression probes to be associated with at least one of the 2549 CpGs. Out of these, 109 CpGs and 27 genes were associated with at least one cardio-metabolic trait in the Rotterdam Study. We were able to replicate the associations with cardio-metabolic traits of 26 CpGs and 19 genes in the KORA study. Furthermore, we identified a three-way association of triglycerides with two CpGs and two genes (GZMA; CLDND1), and BMI with six CpGs and two genes (PID1; LRRN3). Finally, our results revealed the mediation effect of cg03636183 (F2RL3), cg06096336 (PSMD1), cg13708645 (KDM2B), and cg17287155 (AHRR) within the association between smoking and LRRN3 expression. Conclusions Our study indicates that smoking-related changes in DNA methylation and gene expression are associated with cardio-metabolic risk factors. These findings may provide additional insights into the molecular mechanisms linking smoking to the development of CVD.


2018 ◽  
Vol 19 (12) ◽  
pp. 4055 ◽  
Author(s):  
Fatma Zehra Kadayifci ◽  
Shasha Zheng ◽  
Yuan-Xiang Pan

DNA methylation is a vital modification process in the control of genetic information, which contributes to the epigenetics by regulating gene expression without changing the DNA sequence. Abnormal DNA methylation—both hypomethylation and hypermethylation—has been associated with improper gene expression, leading to several disorders. Two types of risk factors can alter the epigenetic regulation of methylation pathways: genetic factors and modifiable factors. Nutrition is one of the strongest modifiable factors, which plays a direct role in DNA methylation pathways. Large numbers of studies have investigated the effects of nutrition on DNA methylation pathways, but relatively few have focused on the biochemical mechanisms. Understanding the biological mechanisms is essential for clarifying how nutrients function in epigenetics. It is believed that nutrition affects the epigenetic regulations of DNA methylation in several possible epigenetic pathways: mainly, by altering the substrates and cofactors that are necessary for proper DNA methylation; additionally, by changing the activity of enzymes regulating the one-carbon cycle; and, lastly, through there being an epigenetic role in several possible mechanisms related to DNA demethylation activity. The aim of this article is to review the potential underlying biochemical mechanisms that are related to diet modifications in DNA methylation and demethylation.


2013 ◽  
Vol 45 (14) ◽  
pp. 565-576 ◽  
Author(s):  
Pao-Yang Chen ◽  
Amit Ganguly ◽  
Liudmilla Rubbi ◽  
Luz D. Orozco ◽  
Marco Morselli ◽  
...  

Maternal nutrient restriction causes the development of adult onset chronic diseases in the intrauterine growth restricted (IUGR) fetus. Investigations in mice have shown that either protein or calorie restriction during pregnancy leads to glucose intolerance, increased fat mass, and hypercholesterolemia in adult male offspring. Some of these phenotypes are shown to persist in successive generations. The molecular mechanisms underlying IUGR remain unclear. The placenta is a critical organ for mediating changes in the environment and the development of embryos. To shed light on molecular mechanisms that might affect placental responses to differing environments we examined placentas from mice that had been exposed to different diets. We measured gene expression and whole genome DNA methylation in both male and female placentas of mice exposed to either caloric restriction or ad libitum diets. We observed several differentially expressed pathways associated with IUGR phenotypes and, most importantly, a significant decrease in the overall methylation between these groups as well as sex-specific effects that are more pronounced in males. In addition, a set of significantly differentially methylated genes that are enriched for known imprinted genes were identified, suggesting that imprinted loci may be particularly susceptible to diet effects. Lastly, we identified several differentially methylated microRNAs that target genes associated with immunological, metabolic, gastrointestinal, cardiovascular, and neurological chronic diseases, as well as genes responsible for transplacental nutrient transfer and fetal development.


2020 ◽  
Author(s):  
Chris Bryan ◽  
Li Lin ◽  
Junkai Xie ◽  
Janiel Ahkin Chin Tai ◽  
Katharine A. Horzmann ◽  
...  

ABSTRACTAtrazine (ATZ) is one of the most commonly used herbicides in the United States. Previous studies have hypothesized the role of ATZ as an endocrine disruptor (EDC), and developmental exposure to ATZ has been shown to lead to behavioral and morphological alterations. Specific epigenetic mechanisms responsible for these alterations, however, are yet to be elucidated. In this study, we exposed zebrafish embryos to 0.3, 3, and 30 ppb (µg/L) of ATZ for 72 hours post fertilization. We performed whole-genome bisulfite sequencing (WGBS) to assess the effects of developmental ATZ exposure on DNA methylation in female fish brains. The number of differentially methylated genes (DMG) increase with increasing dose of treatments. DMGs are enriched in neurological pathways with extensive methylation changes consistently observed in neuroendocrine and reproductive pathways. To assess the effects of DNA methylation on gene expression, we integrated our data with transcriptomic data. Four genes, namely CHD9, FRAS1, PID1, and PCLO, were differentially expressed and methylated in each dose. Overall, this study identifies specific genes and pathways with aberrant methylation and expression following ATZ exposure as targets to elucidate the molecular mechanisms of ATZ toxicity and presents ATZ-induced site-specific DNA methylation as a potential mechanism driving aberrant gene expression.


2021 ◽  
Author(s):  
Yue Zhao ◽  
Chen Wang ◽  
Wangxia Li ◽  
Bingyu Jin ◽  
Yang Xiang ◽  
...  

Abstract BackgroundThe mobidity and mortality of coronary artery disease (CAD) is increasing year by year. Hence it is urgent to probe into the molecular mechanism of CAD and seek new therapeutic strategies. The purpose of our study was to screen genes associated with the development of CAD by using bioinformatics tools and clinical samples. MethodsMicroarray datasets from the Gene Expression Omnibus (GEO) database of peripheral blood cells (PBLs) were chosen for this study, and candidate differentially expressed microRNAs (DEMs) were screened using the limma and weighted co-expression network analysis (WGCNA) packages in R (v4.0). Subsequently, we construct a competitive endogenous RNAs (ceRNA) network and perform enrichment analysis of genes in the network. Meanwhile, differentially methylated genes (DMGs) in PBLs were identified using the "ChAMP" package in a DNA methylation chip. We then constructed the methylation-associated ceRNA network in CAD. Eventually, the methylation levels of genes and the relationship with the expression of genes in ceRNA were validated in PBLs samples using the Illumina Methylation 850K chip and transcriptome sequencing, while gene expressions were verified by qRT-PCR. And the regulation of DNA methylation on gene expression was verified in the THP-1 cells treated with 5-Aza-2'-deoxycytidine (5-AZA). ResultsA total of 71 differentially expressed miRNAs were screened by both WGCNA and limma. Then the ceRNA network in CAD was constructed with 269 nodes and 705 edges, which were significantly enriched in the chemokine-mediated signaling pathway and so on. Furthermore, from 4354 identified DMGs in a methylation data, 34 methylation-associated differentially expressed genes (DEGs) and 1 differentially expressed lncRNA (DEL) were obtained. After verification of methylation experiments in study population A, three genes were found to have altered methylation consistent with the bioinformatics results. And these genes were correlated in terms of methylation and expression levels. Corresponding with the bioinformatics results, qRT-PCR results in validation set B also showed that the expression of AGPAT4 and FAM169A were significantly lower in CAD. In addition, 5-AZA treatment could increase the expression of AGPAT4 and FAM169A in THP-1 cells. ConclusionsOur study deepens the understanding of the molecular mechanisms underlying the pathogenesis of CAD and provides new ideas for its treatment.


2021 ◽  
Vol 55 (4) ◽  
pp. 234-237
Author(s):  
Annamaria Srancikova ◽  
Alexandra Reichova ◽  
Zuzana Bacova ◽  
Jan Bakos

Abstract Objectives. The balance between DNA methylation and demethylation is crucial for the brain development. Therefore, alterations in the expression of enzymes controlling DNA methylation patterns may contribute to the etiology of neurodevelopmental disorders, including autism. SH3 and multiple ankyrin repeat domains 3 (Shank3)-deficient mice are commonly used as a well-characterized transgenic model to investigate the molecular mechanisms of autistic symptoms. DNA methyltransferases (DNMTs), which modulate several cellular processes in neurodevelopment, are implicated in the pathophysiology of autism. In this study, we aimed to describe the gene expression changes of major Dnmts in the brain of Shank3-deficient mice during early development. Methods and Results. The Dnmts gene expression was analyzed by qPCR in 5-day-old homo-zygous Shank3-deficient mice. We found significantly lower Dnmt1 and Dnmt3b gene expression levels in the frontal cortex. However, no such changes were observed in the hippocampus. However, significant increase was observed in the expression of Dnmt3a and Dnmt3b genes in the hypothalamus of Shank3-deficient mice. Conclusions. The present data indicate that abnormalities in the Shank3 gene are accompanied by an altered expression of DNA methylation enzymes in the early brain development stages, therefore, specific epigenetic control mechanisms in autism-relevant models should be more extensively investigated.


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