共查询到18条相似文献,搜索用时 718 毫秒
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植物表观遗传学不仅是基础科学研究的焦点,也是植物育种中获得新资源的一种方式。表观遗传机制可以通过非编码RNA,组蛋白修饰和DNA甲基化控制基因的表达,且越来越多的研究表明表观遗传机制对植物适应环境及胁迫记忆是必要的。本综述重点从DNA甲基化调控、组蛋白变异、组蛋白修饰调控、非编码RNA调控水平论述植物在各种逆境条件下如何通过表观遗传机制来适应环境。 相似文献
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种子活力和DNA甲基化关系的研究进展 总被引:1,自引:0,他引:1
种子活力在发育中逐渐形成,成熟期随着水分的减少,种子获得最大活力。期间发生了许多重要的生理生化反应,如营养物质大量积累、酶和mRNA的钝化等,为种子活力的保持和萌发做好准备。植物中有20%~30%的核基因组DNA胞嘧啶处于甲基化状态,DNA甲基化可以调节基因的表达,维持植物基因组稳定。而植物的DNA甲基化状态在不同器官、不同组织、甚至发育的不同阶段都是不同的,这与遗传和外界环境的刺激相关。在种子的活力形成和萌发过程中,DNA甲基化状态也发生了复杂的变化,这种变化具有种属特异性。种子活力的遗传基础复杂,且受到环境因素的影响。种子经历逆境胁迫时,DNA甲基化状态会发生改变,种子活力水平也会下降,这可能是由于逆境胁迫相关基因的DNA甲基化状态发生变化引起的。 相似文献
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叶锈菌胁迫下的小麦基因组MSAP分析 总被引:10,自引:0,他引:10
内源DNA甲基化是真核生物表观遗传调控的重要组成部分, 在真核生物的基因表达调控中具有重要的作用。生物胁迫为植物提供一种内在的表观遗传进化动力。研究生物胁迫下DNA甲基化的变异模式, 有助于全面理解DNA甲基化的表观调控生物学功能。小麦近等基因系TcLr19、TcLr41及其感病亲本Thatcher在苗期对叶锈菌生理小种THTT、TKTJ分别表现为小种特异性抗病反应和感病反应。文章利用甲基化敏感扩增多态性(Methylation-sensitive amplified polymorphism, MSAP)技术分析了小麦的甲基化水平, 同时比较了苗期在生物胁迫前后基因组DNA胞嘧啶甲基化模式。用60对MSAP引物对接种前后的小麦DNA进行全基因组筛选, 没有直接分离得到接菌前后的甲基化模式的差异, 结果初步表明, 叶锈菌并没有诱导稳定且特异的植物基因组DNA胞嘧啶位点的甲基化模式变化, 但发现TcLr41及其感病亲本Thatcher之间存在表观遗传学差异。 相似文献
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Targets of RNA-directed DNA methylation 总被引:7,自引:0,他引:7
Matzke M Kanno T Huettel B Daxinger L Matzke AJ 《Current opinion in plant biology》2007,10(5):512-519
RNA-directed DNA methylation contributes substantially to epigenetic regulation of the plant genome. Methylation is guided to homologous DNA target sequences by 24 nt 'heterochromatic' small RNAs produced by nucleolar-localized components of the RNAi machinery and a plant-specific RNA polymerase, Pol IV. Plants contain unusually large and diverse populations of small RNAs, many of which originate from transposons and repeats. These sequences are frequent targets of methylation, and they are able to bring plant genes in their vicinity under small RNA-mediated control. RNA-directed DNA methylation can be removed by enzymatic demethylation, providing plants with a versatile system that facilitates epigenetic plasticity. In addition to subduing transposons, RNA-directed DNA methylation has roles in plant development and, perhaps, stress responses. 相似文献
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Conchita Alonso Ricardo Pérez Pilar Bazaga Mónica Medrano Carlos M. Herrera 《Molecular ecology resources》2016,16(1):80-90
Methylation of DNA cytosines affects whether transposons are silenced and genes are expressed, and is a major epigenetic mechanism whereby plants respond to environmental change. Analyses of methylation‐sensitive amplification polymorphism (MS‐AFLP or MSAP) have been often used to assess methyl‐cytosine changes in response to stress treatments and, more recently, in ecological studies of wild plant populations. MSAP technique does not require a sequenced reference genome and provides many anonymous loci randomly distributed over the genome for which the methylation status can be ascertained. Scoring of MSAP data, however, is not straightforward, and efforts are still required to standardize this step to make use of the potential to distinguish between methylation at different nucleotide contexts. Furthermore, it is not known how accurately MSAP infers genome‐wide cytosine methylation levels in plants. Here, we analyse the relationship between MSAP results and the percentage of global cytosine methylation in genomic DNA obtained by HPLC analysis. A screening of literature revealed that methylation of cytosines at cleavage sites assayed by MSAP was greater than genome‐wide estimates obtained by HPLC, and percentages of methylation at different nucleotide contexts varied within and across species. Concurrent HPLC and MSAP analyses of DNA from 200 individuals of the perennial herb Helleborus foetidus confirmed that methyl‐cytosine was more frequent in CCGG contexts than in the genome as a whole. In this species, global methylation was unrelated to methylation at the inner CG site. We suggest that global HPLC and context‐specific MSAP methylation estimates provide complementary information whose combination can improve our current understanding of methylation‐based epigenetic processes in nonmodel plants. 相似文献
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The role of epigenetic processes in controlling flowering time in plants exposed to stress 总被引:2,自引:0,他引:2
Plants interact with their environment by modifying gene expression patterns. One mechanism for this interaction involves epigenetic modifications that affect a number of aspects of plant growth and development. Thus, the epigenome is highly dynamic in response to environmental cues and developmental changes. Flowering is controlled by a set of genes that are affected by environmental conditions through an alteration in their expression pattern. This ensures the production of flowers even when plants are growing under adverse conditions, and thereby enhances transgenerational seed production. In this review recent findings on the epigenetic changes associated with flowering in Arabidopsis thaliana grown under abiotic stress conditions such as cold, drought, and high salinity are discussed. These epigenetic modifications include DNA methylation, histone modifications, and the production of micro RNAs (miRNAs) that mediate epigenetic modifications. The roles played by the phytohormones abscisic acid (ABA) and auxin in chromatin remodelling are also discussed. It is shown that there is a crucial relationship between the epigenetic modifications associated with floral initiation and development and modifications associated with stress tolerance. This relationship is demonstrated by the common epigenetic pathways through which plants control both flowering and stress tolerance, and can be used to identify new epigenomic players. 相似文献
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Roles,and establishment,maintenance and erasing of the epigenetic cytosine methylation marks in plants 总被引:1,自引:0,他引:1
Heritable information in plants consists of genomic information in DNA sequence and epigenetic information superimposed on DNA sequence. The latter is in the form of cytosine methylation at CG, CHG and CHH elements (where H = A, T or C) and a variety of histone modifications in nucleosomes. The epialleles arising from cytosine methylation marks on the nuclear genomic loci have better heritability than the epiallelic variation due to chromatin marks. Phenotypic variation is increased manifold by epiallele comprised methylomes. Plants (angiosperms) have highly conserved genetic mechanisms to establish, maintain or erase cytosine methylation from epialleles. The methylation marks in plants fluctuate according to the cell/tissue/organ in the vegetative and reproductive phases of plant life cycle. They also change according to environment. Epialleles arise by gain or loss of cytosine methylation marks on genes. The changes occur due to the imperfection of the processes that establish and maintain the marks and on account of spontaneous and stress imposed removal of marks. Cytosine methylation pattern acquired in response to abiotic or biotic stress is often inherited over one to several subsequent generations. Cytosine methylation marks affect physiological functions of plants via their effect(s) on gene expression levels. They also repress transposable elements that are abundantly present in plant genomes. The density of their distribution along chromosome lengths affects meiotic recombination rate, while their removal increases mutation rate. Transposon activation due to loss of methylation causes rearrangements such that new gene regulatory networks arise and genes for microRNAs may originate. Cytosine methylation dynamics contribute to evolutionary changes. This review presents and discusses the available evidence on origin, removal and roles of cytosine methylation and on related processes, such as RNA directed DNA methylation, imprinting, paramutation and transgenerational memory in plants. 相似文献
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Heritable alteration in DNA methylation pattern occurred specifically at mobile elements in rice plants following hydrostatic pressurization 总被引:7,自引:0,他引:7
Long L Lin X Zhai J Kou H Yang W Liu B 《Biochemical and biophysical research communications》2006,340(2):369-376
Intrinsic DNA methylation pattern is an integral component of the epigenetic network in many eukaryotes. Exploring the extent to which DNA methylation patterns can be altered under a specific condition is important for elucidating the biological functions of this epigenetic modification. This is of added significance in plants wherein the newly acquired methylation patterns can be inherited through organismal generations. We report here that DNA methylation patterns of mobile elements but not of cellular genes were specifically altered in rice plants following hydrostatic pressurization. This was evidenced by methylation-sensitive gel-blot analysis, which showed that 10 out of 10 studied low-copy transposons and retrotransposons manifested methylation alteration in at least one of the 8 randomly chosen pressure-treated plants, whereas none of the 16 studied low-copy cellular genes showed any change. Both gel-blotting and genome-wide fingerprinting indicated that the methylation alteration in mobile elements was not accompanied by a general genetic instability. Progeny analysis indicated retention of the altered methylation patterns in most progeny plants, underscoring early occurrence of the alterations, and their faithful epigenetic inheritance. 相似文献
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Amr Rafat Elhamamsy 《Cell biochemistry and function》2016,34(5):289-298
DNA methylation is a major epigenetic marking mechanism regulating various biological functions in mammals and plant. The crucial role of DNA methylation has been observed in cellular differentiation, embryogenesis, genomic imprinting and X‐chromosome inactivation. Furthermore, DNA methylation takes part in disease susceptibility, responses to environmental stimuli and the biodiversity of natural populations. In plant, different types of environmental stress have demonstrated the ability to alter the archetype of DNA methylation through the genome, change gene expression and confer a mechanism of adaptation. DNA methylation dynamics are regulated by three processes de novo DNA methylation, methylation maintenance and DNA demethylation. These processes have their similarities and differences between mammals and plants. Furthermore, the dysregulation of DNA methylation dynamics represents one of the primary molecular mechanisms of developing diseases in mammals. This review discusses the regulation and dysregulation of DNA methylation in plants and mammals. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Wang WS Pan YJ Zhao XQ Dwivedi D Zhu LH Ali J Fu BY Li ZK 《Journal of experimental botany》2011,62(6):1951-1960
An indica pyramiding line, DK151, and its recurrent parent, IR64, were evaluated under drought stress and non-stress conditions for three consecutive seasons. DK151 showed significantly improved tolerance to drought. The DNA methylation changes in DK151 and IR64 under drought stress and subsequent recovery were assessed using methylation-sensitive amplified polymorphism analysis. Our results indicate that drought-induced genome-wide DNA methylation changes accounted for ~12.1% of the total site-specific methylation differences in the rice genome. This drought-induced DNA methylation pattern showed three interesting properties. The most important one was its genotypic specificity reflected by large differences in the detected DNA methylation/demethylation sites between DK151 and IR64, which result from introgressed genomic fragments in DK151. Second, most drought-induced methylation/demethylation sites were of two major types distinguished by their reversibility, including 70% of the sites at which drought-induced epigenetic changes were reversed to their original status after recovery, and 29% of sites at which the drought-induced DNA demethylation/methylation changes remain even after recovery. Third, the drought-induced DNA methylation alteration showed a significant level of developmental and tissue specificity. Together, these properties are expected to have contributed greatly to rice response and adaptation to drought stress. Thus, induced epigenetic changes in rice genome can be considered as a very important regulatory mechanism for rice plants to adapt to drought and possibly other environmental stresses. 相似文献