DNA methylation in plants and its role in tissue culture

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 717-729 ◽  
Author(s):  
P. T. H. Brown
Keyword(s):  
Dna Methylation ◽  
Tissue Culture ◽  
Zea Mays ◽  
Somaclonal Variation ◽  
Inbred Line ◽  
Phenotypic Variation ◽  
Methylation Status ◽  
Structural Genes ◽  
Gene Methylation ◽  
Regenerated Plants

Regeneration of plants via tissue culture often results in a number of plants subsequently showing phenotypic or genotypic deviations from the parental type. This variation has been called somaclonal variation. In an analysis of regenerated Zea mays plants of the inbred line A188, high levels of phenotypic variation were observed. Subsequent analysis of these regenerated plants shows that a high proportion of the regenerants demonstrate significant alterations in the methylation status of both housekeeping and structural genes. These results are described and the theory of gene methylation is reviewed with regard to the differences that exist between plant and animal systems.Key words: 5-methylcytosine, 5-azacytidine, tissue culture, cereals, somaclonal variation.

Relative stability among barley plants regenerated from cultured immature embryos

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 405-412 ◽  
Author(s):  
A. Karp ◽  
S. H. Steele ◽  
S. Parmar ◽  
M. G. K. Jones ◽  
P. R. Shewry ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Somaclonal Variation ◽  
Length Polymorphism ◽  
Immature Embryos ◽  
Glutamate Oxaloacetate Transaminase ◽  
Spacer Length ◽  
Factors Affecting ◽  
Regenerated Plants ◽  
Key Words Barley ◽  
Sds Page

Relative genetic stability was observed among barley plants regenerated from cultured immature embryos. Regenerated plants were studied cytologically and their seed progenies assayed for (i) the isoenzymes esterase and glutamate-oxaloacetate transaminase, (ii) ribosomal DNA spacer length polymorphism, and (iii) hordein patterns on SDS–PAGE. Of 42 regenerated plants, 1 regenerant had abnormal meiosis and the same plant produced one seed with a variant hordein pattern. These findings are discussed in relation to the factors affecting somaclonal variation in cereals and to methods of assaying the variation. Key words: barley, isozymes, somaclonal variation, tissue culture.

scholarly journals Somaclonal variation of tissue culture regenerated plants of Aloe barbadensis Mill.

2018 ◽  
Vol 5 (1) ◽  
pp. 72-81
Author(s):  
Zahra Noormohammadi ◽  
Bahar Ghasemzadeh ◽  
Farah Farahani
Keyword(s):  
Tissue Culture ◽  
Somaclonal Variation ◽  
Aloe Barbadensis ◽  
Regenerated Plants

Search for methylation-sensitive amplification polymorphisms associated with the "mantled" variant phenotype in oil palm (Elaeis guineensis Jacq.)

Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 224-228 ◽  
Author(s):  
E Jaligot ◽  
T Beulé ◽  
F-C Baurens ◽  
N Billotte ◽  
A Rival
Keyword(s):  
Dna Methylation ◽  
Somaclonal Variation ◽  
Oil Palm ◽  
Elaeis Guineensis ◽  
Methylation Status ◽  
Methylation Pattern ◽  
Variant Phenotype ◽  
Elaeis Guineensis Jacq ◽  
The Moment ◽  
Direct Use

The methylation-sensitive amplification polymorphism (MSAP) technique has been employed on somatic embryo-derived oil palms (Elaeis guineensis Jacq.) to identify methylation polymorphisms correlated with the "mantled" somaclonal variation. The variant phenotype displays an unstable feminization of male organs in both male and female flowers. Using MSAP, the methylation status of CCGG sites was compared in three normal versus three mantled regenerants sampled in clonal populations obtained through somatic embryogenesis from four genotypically distinct mother palms. Overall, 64 selective primer combinations were used and they have amplified 23 markers exhibiting a differential methylation pattern between the two phenotypes. Our results indicate that CCGG sites are poorly affected by the considerable decrease in global DNA methylation that has been previously associated with the mantled phenotype. Each of the 23 markers isolated in the present study could discriminate between the two phenotypes only when they were from the same genetic origin. This result hampers at the moment the direct use of MSAP markers for the early detection of variants, even though valuable information on putative target sequences will be obtained from a further characterization of these polymorphic markers.Key words: DNA methylation, epigenetics, MSAP, oil palm, somaclonal variation.

scholarly journals Quantitative and correlation analysis of the DNA methylation and expression of DAPK in breast cancer

2016 ◽  
Author(s):  
Youzhi Zhu ◽  
Shuiqin Li ◽  
Qingshui Wang ◽  
Ling Chen ◽  
Kunlin Wu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Methylation ◽  
Protein Expression ◽  
Methylation Status ◽  
Clinicopathological Characteristics ◽  
Clinicopathological Parameters ◽  
Gene Methylation ◽  
Methylation Rate ◽  
Death Associated Protein Kinase ◽  
Mrna And Protein Expression

Backgound. Death associated protein kinase 1 (DAPK) is an important tumor suppressor kinase involved in the regulation of multiple cellular activities such as apoptosis and autophagy. DNA methylation of DAPK gene was found in various types of cancers and often correlated with the clinicopathological characteristics. However, the mRNA and protein expression of DAPK in the same sample was rarely measured. Thus it was unclear if the correlation between DAPK gene methylation and clinicopathological parameters was due to the loss of DAPK expression. Methods. In this study, the DNA methylation rate, mRNA and protein expression of DAPK was quantitatively detected in 15 pairs of breast cancer patient samples including tumor (T) and adjacent non-tumor (N) tissues. Results. The correlation between DNA methylation rate and mRNA expression, together with the correlation between mRNA and protein expression, was calculated. No correlation was observed between any levels using either the measurement value of each sample or the T/N ratio of each pair. Discussion. These data suggested the DNA methylation status of DAPK did not correlate well with its mRNA or protein expression. Extra caution is needed when interpreting the DNA methylation data of DAPK gene in clinical studies.

scholarly journals Extracellular Superoxide Dismutase (EC-SOD) Regulates Gene Methylation and Cardiac Fibrosis During Chronic Hypoxic Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Ayan Rajgarhia ◽  
Kameshwar R. Ayasolla ◽  
Nahla Zaghloul ◽  
Jorge M. Lopez Da Re ◽  
Edmund J. Miller ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Tissue Culture ◽  
Superoxide Dismutase ◽  
Cardiac Fibrosis ◽  
Extracellular Superoxide Dismutase ◽  
Hypoxic Stress ◽  
Fibroblast Proliferation ◽  
Gene Methylation ◽  
Hypoxic Group

Chronic hypoxic stress induces epigenetic modifications mainly DNA methylation in cardiac fibroblasts, inactivating tumor suppressor genes (RASSF1A) and activating kinases (ERK1/2) leading to fibroblast proliferation and cardiac fibrosis. The Ras/ERK signaling pathway is an intracellular signal transduction critically involved in fibroblast proliferation. RASSF1A functions through its effect on downstream ERK1/2. The antioxidant enzyme, extracellular superoxide dismutase (EC-SOD), decreases oxidative stress from chronic hypoxia, but its effects on these epigenetic changes have not been fully explored. To test our hypothesis, we used an in-vitro model: wild-type C57B6 male mice (WT) and transgenic males with an extra copy of human hEC-SOD (TG). The studied animals were housed in hypoxia (10% O2) for 21 days. The right ventricular tissue was studied for cardiac fibrosis markers using RT-PCR and Western blot analyses. Primary C57BL6 mouse cardiac fibroblast tissue culture was used to study the in-vitro model, the downstream effects of RASSF-1 expression and methylation, and its relation to ERK1/2. Our findings showed a significant increase in cardiac fibrosis markers: Collagen 1, alpha smooth muscle actin (ASMA), and SNAIL, in the WT hypoxic animals as compared to the TG hypoxic group (p < 0.05). The expression of DNA methylation enzymes (DNMT 1&3b) was significantly increased in the WT hypoxic mice as compared to the hypoxic TG mice (p < 0.001). RASSF1A expression was significantly lower and ERK1/2 was significantly higher in hypoxia WT compared to the hypoxic TG group (p < 0.05). Use of SiRNA to block RASSF1A gene expression in murine cardiac fibroblast tissue culture led to increased fibroblast proliferation (p < 0.05). Methylation of the RASSF1A promoter region was significantly reduced in the TG hypoxic group compared to the WT hypoxic group (0.59 vs. 0.75, respectively). Based on our findings, we can speculate that EC-SOD significantly attenuates RASSF1A gene methylation and can alleviate cardiac fibrosis induced by hypoxia.

scholarly journals Assessment of Epigenetic and Phenotypic Variation in Populus nigra Regenerated via Sequential Regeneration

2021 ◽  
Vol 12 ◽  
Author(s):  
Weixi Zhang ◽  
Yanbo Wang ◽  
Shu Diao ◽  
Shanchen Zhong ◽  
Shu Wu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Phenotypic Variation ◽  
Populus Nigra ◽  
Utilization Efficiency ◽  
Plant Genome ◽  
Physiological Traits ◽  
Somatic Variation ◽  
Regenerated Plants ◽  
Significant Difference ◽  
Almost All

Somatic variation has been demonstrated in tissue culture regenerated plants of many species. In the genus Populus, phenotypic variation caused by changes in 5-methylcytosine within the plant genome have been reported. To date, the phenotypic and epigenetic stability of plants regenerated from sequential regeneration has not been tested in trees. In this study, we detected DNA methylation of CCGG sites in regenerated plants of five generations in Populus nigra using methylation-sensitive amplified polymorphisms, and evaluated their growth performance and physiological traits. About 10.86–26.80% of CCGG sites in the regenerated plant genome were demethylated and 5.50–8.45% were methylated, resulting in significantly lower DNA methylation levels among all regenerated plants than among donor plants. We detected a significant difference in methylation levels between first regeneration regenerated plants (G1) and those of the other four generations (G2–G5); there were no significant differences among the four later generations. Therefore, the dramatic decrease in DNA methylation levels occurred only in the first and second poplar regenerations; levels then stabilized later in the regeneration process, indicating that two regeneration events were sufficient to change the methylation statuses of almost all CCGG sites sensitive to regeneration. Differences in growth and physiological traits were observed between regenerated plants and donor plants, but were significant only among plants of certain generations. Significant correlations were detected between methylation level and transpiration rate, net photosynthetic rate, peroxidase activity, and instant water utilization efficiency, indicating the involvement of epigenetic regulation in this unpredictable phenotypic variation.

scholarly journals Somaclonal variation in triticale (×Triticosecale Wittmack) cv. Carman

1985 ◽  
Vol 27 (2) ◽  
pp. 151-157 ◽  
Author(s):  
M. C. Jordan ◽  
E. N. Larter
Keyword(s):  
Tissue Culture ◽  
Plant Regeneration ◽  
Somaclonal Variation ◽  
Chromosomal Instability ◽  
Dichlorophenoxyacetic Acid ◽  
Ms Medium ◽  
Regenerated Plants ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Triticosecale Wittmack ◽  
Kernel Protein

Callus was initiated from 15-day-old embryos of 'Carman' triticale (×Triticosecale Wittmack) cultured on 2,4-dichlorophenoxyacetic acid supplemented Murashige and Skoog (MS) medium. For plant regeneration, the calli were subcultured every 4 weeks on MS media with no added hormones. The original euploid (2n = 42) regenerated plants and their progeny were examined for several traits. Considerable variation for all measured traits was observed among the regenerated plants. Variability was greatest for spike length, fertility, and plant height. Two second-generation plants were found to have a significant increase in percent kernel protein relative to 'Carman' controls. Electrophoretic studies showed that all regenerated plants of both generations had the same prolamin banding pattern as 'Carman' triticale but variation existed in the intensity of the bands. This was especially true for the bands encoded for by the rye genome. One genotype, viz. R13, exhibited extreme chromosomal instability resulting in the occurrence of both rye and wheat univalents as observed at metaphase I.Key words: somaclonal variation, triticale, tissue culture, plant regeneration.

Genetic variants in progeny of regenerated maize plants

Genome ◽  
1987 ◽  
Vol 29 (6) ◽  
pp. 834-838 ◽  
Author(s):  
Michael Lee ◽  
R. L. Phillips
Keyword(s):  
Tissue Culture ◽  
Zea Mays ◽  
Zea Mays L ◽  
Single Gene ◽  
Callus Cultures ◽  
Regenerated Plants ◽  
Two Generations ◽  
Frequent Variant ◽  
Maize Plants ◽  
Regenerated Plant

Tissue culture has been shown to be a method of generating genetic variation in regenerated plants and their progeny for several maize (Zea mays L.) genotypes. The objectives of this study were to (i) estimate the frequency and types of variants arising from maize tissue cultures, (ii) investigate the effect of culture age on the frequency of variants per regenerated plant, and (iii) estimate the frequency of sectoring among regenerated plants of an F3 from Oh43/A188 genetic background that had not been examined previously for genetic stability in culture. Organogenic callus cultures were initiated from immature F3 embryos for several Oh43ms isoline × A188 crosses. Plants were regenerated either 3 to 4 or 8 to 9 months after culture initiation. Progenies of 248 plants regenerated from 74 cultures were scored for kernel, seedling, and other sporophytic variants following one or two generations of self-pollination. The frequency of variants per regenerated plants increased from 0.5 after 3 to 4 months of culture to 1.3 after 8 to 9 months. A total of 44 variant phenotypes were observed. Defective kernels were the most frequent variant. Most variants were inherited as single-gene recessives. Segregation patterns suggested that the ear and tassel of several (40 of 80) self-pollinated, regenerated plants were genetically discordant. Key words: Zea mays L., tissue culture, somaclonal variation, chimera, qualitative variation.

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