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细胞程序死亡(PCD)是在植物体发育过程中普遍存在的,在发育的特定阶段发生的自然的细胞死亡过程,这一死亡过程是由某些特定基因编码的“死亡程序”控制的。PCD是细胞分化的最后阶段。细胞分化的临界期就处于死亡程序执行中的某个阶段。PCD包含启动期、效应期和清除期三个阶段,其间caspase家族起着重要作用。PCD在细胞和组织的平衡、特化,以及组织分化、器官建成和对病原体的反应等植物发育过程中起着重要作用。PCD中的形态学变化和生物化学变化都有着严格的时序性。植物的PCD和动物的PCD有许多共性,包括细胞形态和DNA降解等变化。也有一些不同,植物PCD的产物既可被其它细胞吸收利用;也可用于构建自身的次生细胞壁。 相似文献
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液泡是植物细胞专一性器官之一,具有多种功能,参与细胞内环境调节和细胞解毒等过程。研究表明,液泡在植物细胞程序性死亡(programmed cell death,PCD)中具有重要作用。在液泡介导的PCD过程中,液泡加工酶(vacuolar processing enzyme,VPE)的调控和激活是PCD的关键环节。着眼于液泡信号通路依赖的PCD,对相关细胞事件和分子调控机制进行了讨论,并对未来的研究方向作了展望,以期能推进PCD机制解明。 相似文献
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细胞程序性死亡(PCD)对于维持植物的正常生长发育非常重要,目前已成为植物学研究的一个热点。本文综合评述了近年来植物PCD研究的某些进展,包括植物PCD的特征,植物的营养生长、生殖生长以及与环境互作过程中存在的各种PCD及其证据,植物PCD发生的分子机制及其调控等等。对植物PCD研究中有待进一步解决的问题和可能意义提出了自己的见解。 相似文献
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以入侵植物飞机草的不同时期花蕾为材料,利用RT-PCR法扩增得到了与PCD相关的类Beclin1基因的部分cDNA序列(大约700bp),与烟草叶片中的基因序列(AY701316)同源性为95%;Northern blotting结果表明类Beclin1基因。在花蕾发育中期的表达量高于初期和后期;通过DNA ladder检测表明在花蕾发育过程中伴随着PCD的发生,这些结果表明花蕾发育中期是PCD初期发生的活跃期,是绒毡层逐渐退化和花粉不断形成的过程。通过对生殖过程中的细胞程序性死亡的分子生物学研究,初步揭示了飞机草入侵过程与PCD的相互关系。 相似文献
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环境胁迫下的植物细胞程序性死亡及其意义 总被引:5,自引:0,他引:5
从低氧适应、抗病反应、抗盐机制等方面阐明了环境胁迫下的植物细胞程序性死亡(PCD)的普遍性,并就PCD在植物抵御不良环境中的意义进行讨论。 相似文献
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以入侵植物飞机草的不同时期花蕾为材料,利用RT-PCR法扩增得到了与PCD相关的类Beclin1基因的部分cDNA序列(大约700 bp),与烟草叶片中的基因序列(AY701316)同源性为95%;Northern blotting结果表明类Beclin1基因在花蕾发育中期的表达量高于初期和后期;通过DNA ladder检测表明在花蕾发育过程中伴随着PCD的发生,这些结果表明花蕾发育中期是PCD初期发生的活跃期,是绒毡层逐渐退化和花粉不断形成的过程.通过对生殖过程中的细胞程序性死亡的分子生物学研究,初步揭示了飞机草入侵过程与PCD的相互关系. 相似文献
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Developmental programmed cell death in plants 总被引:16,自引:0,他引:16
Mechanisms of plant developmental programmed cell death (PCD) have been intensively studied in recent years. Most plant developmental PCD is triggered by plant hormones, and the 'death signal' may be transduced by hormonal signaling pathways. Although there are some fundamental differences in the regulation of developmental PCD in various eukaryotes of different kingdoms, hormonal control and death signal transduction via pleiotropic signaling pathways constitute a common framework. However, plants possess a unique process of PCD execution that depends on vacuolar lytic function. Comparisons of the developmental PCD mechanisms of plants and other organisms are providing important insights into the detailed characteristics of developmental PCD in plants. 相似文献
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Primary roots of two species of Sonoran Desert Cactaceae, Stenocereus gummosus and Pachycereus pringlei, have a determinate pattern of growth: meristematic cells divide only for a limited time and then differentiate. Detecting DNA fragmentation by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL), we have shown that programmed cell death (PCD) was not involved in meristem exhaustion. However, we found TUNEL-positive nuclei in the root hair and root cap cells of both species. Programmed cell death in root hair cells has not been previously reported, and the pattern of PCD events in the root cap differed from that described earlier. These data suggest that in the studied Cactaceae, PCD is involved in developmental adaptations related to the formation of a compact root system important for rapid seedling establishment in a desert environment. Participation of PCD in developmental loss of the root cap and in root hair renovation proposed in the current study implicates an evolutionary conserved link between PCD and differentiation processes in plants. 相似文献
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Jaana Vuosku Suvi Sutela Eila Tillman-Sutela Anneli Kauppi Anne Jokela Tytti Sarjala Hely H?ggman 《Plant signaling & behavior》2009,4(10):928-932
In plants, programmed cell death (PCD) is an important mechanism that controls normal growth and development as well as many defence responses. At present, research on PCD in different plant species is actively carried out due to the possibilities offered by modern methods in molecular biology and the increasing amount of genome data. The pine seed provides a favourable model for PCD because it represents an interesting inheritance of seed tissues as well as an anatomically well-described embryogenesis during which several tissues die via morphologically different PCD processes.Key words: conifer, developmental cell death, embryogenesis, megagametophyte, necrotic cell death, pine, seed development 相似文献
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Plant mitochondrial pathway leading to programmed cell death 总被引:3,自引:0,他引:3
Angelo Vianello Marco Zancani Carlo Peresson Elisa Petrussa Valentino Casolo Jana Krajáková Sonia Patui Enrico Braidot Francesco Macrì 《Physiologia plantarum》2007,129(1):242-252
Programmed cell death (PCD) is a finely tuned process of multicellular organisms. In higher plants, PCD regulates many developmental processes and the response of host plants to incompatible pathogens (hypersensitive response). Four types of PCD have been described in plants, mainly associated to vacuole rupture, that is followed by the appearance of the typical PCD hallmarks (i.e. nuclear DNA fragmentation and cell shrinkage). However, in some cases vacuole collapse is preceded by an early alteration of other subcellular organelles, such as mitochondria. In particular, the central role played by mitochondria in PCD has been largely recognised in animal cells. This review deals with the involvement of mitochondria in the manifestation of plant PCD, in comparison to that described in animal PCD. The main hallmark, connecting animal and plant PCD via mitochondria, is represented by the release of cytochrome c and possibly other chemicals such as nucleases, which may be accomplished by different mechanisms, involving both swelling and non-swelling of the organelles. 相似文献
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Transgene-induced lesion mimic 总被引:17,自引:0,他引:17
Lesion mimic, i.e., the spontaneous formation of lesions resembling hypersensitive response (HR) lesions in the absence of a pathogen, is a dramatic phenotype occasionally found to accompany the expression of different, mostly unrelated, transgenes in plants. Recent studies indicated that transgene-induced lesion formation is not a simple case of necrosis, i.e., direct killing of cells by the transgene product, but results from the activation of a programmed cell death (PCD) pathway. Moreover, activation of HR-like cell death by transgene expression is viewed as an important evidence for the existence of a PCD pathway in plants. The study of lesion mimic transgenes is important to our understanding of PCD and the signals that control it in plants. PCD-inducing transgenes may provide clues regarding the different entry points into the cell death pathway, the relationships between the different branches of the pathway (e.g., developmental or environmental), or the different mechanisms involved in its induction or execution. Cell death-inducing transgenes may also be useful in biotechnology. Some lesion mimic transgenes were found to be induced in plants a state of systemic acquired resistance (SAR). These genes can be used in the development of pathogen-resistant crops. Other cell death-inducing transgenes may be used as specific cell ablation tools. Although mainly revealed unintentionally, and at times considered `an adverse phenotype', lesion mimic transgenes should not be ignored because they may prove valuable for studying PCD as well as developing useful traits in different plants and crops. 相似文献
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Programmed cell death (PCD) functions in the developmental remodeling of leaf shape in higher plants, a process analogous to digit formation in the vertebrate limb. In this study, we provide a cytological characterization of the time course of events as PCD remodels young expanding leaves of the lace plant. Tonoplast rupture is the first PCD event in this system, indicated by alterations in cytoplasmic streaming, loss of anthocyanin color, and ultrastructural appearance. Nuclei become terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling positive soon afterward but do not become morphologically altered until late stages of PCD. Genomic DNA is fragmented, but not into internucleosomal units. Other cytoplasmic changes, such as shrinkage and degradation of organelles, occur later. This form of PCD resembles tracheary element differentiation in cytological execution but requires unique developmental regulation so that discrete panels of tissue located equidistantly between veins undergo PCD while surrounding cells do not. 相似文献
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Programmed cell death (PCD), a topic of abiding interest, remodels plants at the cell, tissue, and organ levels involving
various developmental processes of plants. The aim of this study is to provide a morphological characterization of evidence
of PCD involvement in the laticiferous canal formation in fruit of Decaisnea fargesii. Several ultrastructural features of PCD have been observed including disintegration of vacuole and plasma membranes, cell
wall degeneration, degenerated cytoplasm, abundant membrane structures and flocculent material, mitochondria and misshapen
nuclei coupled with degraded plastids in vacuoles, and nuclei enveloped by rubber granule. In D. fargesii, the nuclei of the secretory epidermal cells become TUNEL-positive from the sunken stage to the late expanding stage, then
DAPI-negative during the mature stage, indicating an early event of deoxyribonucleic acid (DNA) cleavage and a late event
of complete DNA degeneration. Gel electrophoresis indicates that DNA cleavage is random and does not result in the laddering
pattern indicating multiples of internucleosomal units. During the PCD of secretory epidermal cells, the rubber granules continue
to be synthesized and accumulated in the secretory epidermal cells despite nuclear degradation. The PCD’s role in laticiferous
canal formation suggests that PCD may play important roles in gland development of plants. 相似文献
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Eva Dvok Tomatíkov Anders Hafrn Minerva S Trejo-Arellano Sheena Ricafranca Rasmussen Hikaru Sato Juan Santos-Gonzlez Claudia Khler Lars Hennig Daniel Hofius 《Plant physiology》2021,185(4):2003
The Polycomb Repressive Complex 2 (PRC2) is well-known for its role in controlling developmental transitions by suppressing the premature expression of key developmental regulators. Previous work revealed that PRC2 also controls the onset of senescence, a form of developmental programmed cell death (PCD) in plants. Whether the induction of PCD in response to stress is similarly suppressed by the PRC2 remained largely unknown. In this study, we explored whether PCD triggered in response to immunity- and disease-promoting pathogen effectors is associated with changes in the distribution of the PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) modification in Arabidopsis thaliana. We furthermore tested the distribution of the heterochromatic histone mark H3K9me2, which is established, to a large extent, by the H3K9 methyltransferase KRYPTONITE, and occupies chromatin regions generally not targeted by PRC2. We report that effector-induced PCD caused major changes in the distribution of both repressive epigenetic modifications and that both modifications have a regulatory role and impact on the onset of PCD during pathogen infection. Our work highlights that the transition to pathogen-induced PCD is epigenetically controlled, revealing striking similarities to developmental PCD.Changes in histone modifications mediated by Polycomb Repressive Complex 2 and KRYPTONITE play a regulatory role in pathogen-induced programmed cell death in Arabidopsis. 相似文献
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Programmed cell death (PCD) in plants is a crucial componentof development and defence mechanisms. In animals, differenttypes of cell death (apoptosis, autophagy, and necrosis) havebeen distinguished morphologically and discussed in these morphologicalterms. PCD is largely used to describe the processes of apoptosisand autophagy (although some use PCD and apoptosis interchangeably)while necrosis is generally described as a chaotic and uncontrolledmode of death. In plants, the term PCD is widely used to describemost instances of death observed. At present, there is a vastarray of plant cell culture models and developmental systemsbeing studied by different research groups and it is clear fromwhat is described in this mass of literature that, as with animals,there does not appear to be just one type of PCD in plants.It is fundamentally important to be able to distinguish betweendifferent types of cell death for several reasons. For example,it is clear that, in cell culture systems, the window of timein which PCD is studied by different groups varieshugely and this can have profound effects on the interpretationof data and complicates attempts to compare different researcher'sdata. In addition, different types of PCD will probably havedifferent regulators and modes of death. For this reason, inplant cell cultures an apoptotic-like PCD (AL-PCD) has beenidentified that is fairly rapid and results in a distinct corpsemorphology which is visible 4–6 h after release of cytochromec and other apoptogenic proteins. This type of morphology, distinctfrom autophagy and from necrosis, has also been observed inexamples of plant development. In this review, our model systemand how it is used to distinguish specifically between AL-PCDand necrosis will be discussed. The different types of PCD observedin plants will also be discussed and the importance of distinguishingbetween different forms of cell death will be highlighted. Key words: Apoptosis, apoptosis-like programmed cell death (AL-PCD), Arabidopsis, autophagy, mitochondria, necrosis, programmed cell death (PCD)
Received 5 June 2007; Revised 13 September 2007 Accepted 20 September 2007 相似文献