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植物茎分枝的分子调控 总被引:4,自引:0,他引:4
植物茎分枝结构决定了不同植物的不同形态结构.本文从腋生分生组织的发生、腋芽的生长两个方面综述了近年来植物分枝发生发育相关的分子机理研究及其进展.发现在不同植物中腋分生组织形成的基本机制是相似的,LS(lateral suppressor)及其同源基因在不同植物中都参与腋生分生组织的形成,而BL(blind)及其同源基因也参与调控腋生分生组织的形成.腋生分生组织的形成可能也是受激素调控的.目前,对腋芽生长的分子调控机制的认识主要集中于生长素通过二级信使的作用调控腋芽的生长.而生长素调控腋芽生长的机制已经较为清楚的有两条途径:一是生长素通过抑制细胞分裂素合成来调控腋芽的生长;另一途径是一种类胡萝卜素衍生的信号物质参与生长素的运输调控(MAX途径)来调控腋芽的生长.最新研究表明,TB1的拟南芥同源基因在MAX途径的下游负调控腋芽的生长.此外,增强表达OsNAC2也促进腋芽的生长. 相似文献
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植物衰老是由内外环境因子共同调节的,发生在细胞、组织、器官和个体等多个层面上的衰退和死亡过程,涉及基因表达、蛋白翻译和修饰水平变化以及多种细胞结构和代谢途径的变化,并与激素和生物/非生物胁迫的应答等过程形成复杂的调控网络。近年的研究表明,表观遗传修饰参与了对植物衰老过程的调节,是除经典遗传学以研究基因序列影响生物学功能之外在非核酸序列改变的情况下导致可遗传的基因表达变化的机制。本文综述了植物衰老过程中表观遗传调控的机理,包括染色质构象变化、DNA甲基化、组蛋白修饰、ATP依赖的重构因子和非编码RNA介导的调控等,并对这一领域今后的发展方向进行了展望。 相似文献
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真核生物基因表达受到染色质结构的调控,组蛋白与DNA的共价修饰构成表观遗传标签,并在植物胁迫应答如防御病原菌侵染过程中起重要作用.病原菌侵染可引起基因组整体DNA甲基化模式变化及胁迫应答基因的位点特异性去甲基化,导致植物抗性基因表达上调或下调,并进一步调控植物对病原菌的胁迫应答;组蛋白去乙酰化酶HDAC通过茉莉酸途径增强植物对病原菌的胁迫应答;此外,染色质重塑复合物Swr1复合体通过识别DNA基元和组蛋白乙酰化修饰状态靶向基因启动子,负调控SA敏感基因.该文从DNA甲基化、组蛋白乙酰化、甲基化修饰,染色质重塑等方面着重阐述植物与病原菌互作过程中发生的主要事件的分子基础及其研究进展. 相似文献
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植物叶片衰老是一个非常重要的发育过程,涉及大分子的有序分解从而将营养物质从叶片转移到其他器官,对植物的生存和适应至关重要。叶片衰老主要受植物的发育调控,但同时也受内部和外部环境因素的影响,涉及高度复杂的基因调控网络和多层级的调控。近年来的研究表明表观遗传是调控植物叶片衰老的一种重要调控方式。该研究综述了植物叶片衰老过程中的表观遗传调控机制,包括组蛋白修饰、DNA甲基化、ATP依赖的染色质重塑和非编码RNA介导的调控,并对该领域今后的发展方向进行了展望。 相似文献
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花青苷是广泛存在于植物中的一类重要的类黄酮化合物,对植物生长、代谢、应激等方面具有重要作用。在植物生长发育过程中,花青苷使植物的花和果实呈现出丰富色彩的颜色,从而吸引昆虫传粉和动物采食,便于结种和传播;在植物代谢应激反应中,花青苷使植物具有抵御低温、干旱、真菌感染,防御紫外线伤害、虫害等能力。花青苷生物合成通路受相关结构基因和转录因子的调控机制已被解析得十分清楚,近几年研究发现,植物花青苷生物合成相关基因受到表观调控,从而影响花青素苷的合成。表观遗传学是目前生命科学领域研究的热点之一,本文结合最新的植物花青苷合成表观遗传学研究进展,综述了花青苷合成过程中的表观遗传修饰以及基因编辑技术在表观遗传学研究中的应用,以期利用表观遗传手段为花色育种改良提供新思路。 相似文献
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阿尔茨海默病(Alzheimer’s disease,AD)是一种临床上常见的以进行性认知功能障碍和记忆减退为主要特征的神经退行性疾病。近些年研究发现,表观遗传修饰如DNA修饰、组蛋白修饰、RNA修饰及非编码RNA在Aβ沉积、Tau蛋白过度磷酸化、神经再生、突触可塑性和认知功能中发挥不同程度的调控作用,进而改善或加剧AD病理进程。临床数据表明表观遗传修饰的改变与AD风险呈显著相关性,运用药物、物理刺激、si RNA等干预手段在AD动物模型中改变表观遗传修饰水平可改善AD病理和认知能力。本文综述了不同的表观遗传修饰在AD中的调控作用,为进一步理解AD的表观遗传学机制及通过干预表观遗传修饰改善或治疗AD的可行性提供理论依据。 相似文献
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Plant branching development plays an important role in plant morphogenesis (aboveground plant type), the number and angle of branches are important agronomic characters that determine crop plant type. Effective branches determine the number of panicles or pods of crops and then control the yield of crops. With the rapid development of plant genomics and molecular genetics, great progress has been made in the study of branching development. In recent years, a series of important branching-related genes have been validated from Arabidopsis thaliana, rice, pea, tomato and maize mutants. It is reviewed that plant branching development is controlled by genetic elements and plant hormones, such as auxin, cytokinin and lactones (or lactone derivatives), as well as by environment and genetic elements. Meanwhile, shoot architecture in crop breeding was discussed in order to provide theoretical basis for the study of crop branching regulation. 相似文献
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In the plagiotropic nodally rooting clonal herb, Trifolium repens,the development of branches on stems is primarily controlled by the presence of nodal roots, and apical dominance is of secondary importance; only six to ten branches form distal to the youngest nodal root on a horizontal stem. We assessed the hypothesis that this phenomenon is general for clonal herbs with prostrate nodally rooting stems, and that they all have the same physiological system regulating branching, by testing a selection of species from diverse angiosperm families that exhibit either phalanx (Leptinella (Asteraceae), Hydrocotyle (Apiaceae), Acaena (Rosaceae)) or guerilla (Vinca (Apocynaceae), Glechoma and Lamiastrum (Lamiaceae)) growth strategies. In all these species the establishment of a single nodal root on a prostrate stem, otherwise prevented from nodally rooting, induced the outgrowth of a limited number of axillary buds (the number of which was species specific) at the nodes immediately distal to the newly established root, thereby indicating a phenotypic response similar to that in T. repens. Furthermore, their branching responses to manipulative treatments were also similar to those of T. repens, indicating that their regulatory physiology of axillary bud outgrowth from their prostrate stems is similar. We conclude that, for the group of prostrate nodally rooting clonal herbs as a whole, the apical dominance phenotype arises predominantly from variation in the supply of resources from nodal roots rather than from repression of axillary buds by apical tissues (apical dominance). We suggest that evolution of such a physiological mechanism enhances the exploration for patchily distributed favourable nodal rooting sites by regulating shoot development so as to efficiently utilise the diminishing intra-plant availability of root-supplied resources. For the species examined, inter-specific variation in intensity of branching response to a nodal root is shown to be linked to a trade off in foraging strategy, with the allocation of resources primarily to explorative growth (long internodes, few branches) in guerilla species or to exploitive growth (short internodes, many branches) in phalanx species.Co-ordinating editor: J. Tuomi 相似文献
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rDNA是控制细胞核糖体生物合成的串联重复基因,影响着整体蛋白质的翻译水平,与细胞生长代谢息息相关.由于rDNA序列具有多拷贝的重复特征,其转录除了受一般转录机制的调节外,还受多重表观调控机制的调节,精细调控着rDNA的转录状态.一般认为rDNA分为活跃和沉默两种状态,分别与活跃染色质标记和异染色质标记相关.近些年来,发现一种平衡态rDNA的存在,更加丰富了rDNA表观机制的研究.H3.3是一种H3组蛋白变体,是近些年来的研究热点,已有报道H3.3可能在分子伴侣HIRA的介导下整合进入活跃rDNA,然而沉默rDNA的维持是否也与H3.3的作用相关需要更多的探索.CTCF是rDNA重复单元间的绝缘子成分,与H3.3相关但并不清楚是否也调控着rDNA的转录.该综述讨论了几种调控rDNA表观状态的机制,并对可能参与该过程的新机制提出了设想. 相似文献
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乳腺癌是影响女性健康最主要的恶性肿瘤之一.表观遗传修饰及活性氧(ROS)过度积累引起的氧化应激在乳腺癌发生发展中起关键作用,表观遗传修饰与ROS的生成和清除相互影响.本文通过对目前有关表观遗传修饰和ROS参与乳腺癌的发生发展进行综述,为寻求乳腺癌发生发展的生物标志物及精准治疗提供思路. 相似文献
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磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxykinase,PEPC)家族蛋白普遍存在各种植物中,在光合碳同化过程中起到重要作用,同时具有多种非光合生物学功能,但PEPC基因在苹果(Malus domestica Borkh.)中尚未研究报道。本研究以苹果新基因组数据为基础,利用生物信息学方法对苹果PEPC家族成员(the members of apple PEPC family,MdPEPC)进行鉴定,并对其在不同组织中的表达谱以及去顶和细胞分裂素噻重氮苯基脲(thidazuron,TDZ)处理后苹果腋芽转录组中的表达模式进行分析,以期探究MdPEPC基因在参与苹果腋芽萌发中的作用。结果表明,苹果MdPEPC家族共有6个成员,分布于6条不同的染色体上,且理化特征较为相似;系统进化树及序列比对分析显示其可分为2个亚组(Group Ⅰ和Group Ⅱ),其中Ⅰ组含4个MdPEPC家族成员,属于植物型PEPCs,而MdPEPC4和MdPEPC5则与拟南芥细菌型AtPPC4聚类到Ⅱ组;共线性分析表明,MdPEPC成员之间不存在串联重复,含7对片段重复;顺式作用元件分析显示,MdPEPC家族成员不仅受光和逆境等影响,还受多种激素综合调控;表达谱显示,除MdPEPC4和MdPEPC5外,其他植物型MdPEPC在不同组织中均有表达。转录组数据分析表明,去顶和TDZ处理后MdPEPC1和MdPEPC3表达量上调,而MdPEPC2则在处理后48 h明显下调表达。综上所述,本研究通过对苹果MdPEPC家族的鉴定和分析,筛选出MdPEPC1、MdPEPC2和MdPEPC3作为调控苹果腋芽萌发的候选基因,以便后期对其进行深入研究。 相似文献
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Plant architecture, a collection of the important agronomic traits that determine grain production in rice, is mainly affected
by factors including tillering, plant height and panicle morphology. Recently, significant progress has been made in isolating
and collecting of mutants that are defective in rice plant architecture. Although our understanding of the molecular mechanisms
that control rice tillering, panicle development and plant height are still limited, new findings have begun to emerge. This
review, therefore, summarizes the recent progress in exploring the mechanisms that control rice plant architecture. 相似文献
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The role of hormones in apical dominance. New approaches to an old problem in plant development 总被引:19,自引:0,他引:19
Morris G. Cline 《Physiologia plantarum》1994,90(1):230-237
The role of hormones in apical dominance has been under investigation with traditional 'spray and weigh' methods for nearly 5 decades. Even though the precision of hormone content analyses in tissue has greatly improved in recent years, there have been no significant breakthroughs in our understanding of the action mechanism of this classical developmental response. Auxin appears to inhibit axillary bud outgrowth whereas cytokinins will often promote it. Conclusive evidence for a direct role of these or other hormones in apical dominance has not been forthcoming. However, promising new tools and approaches recently have begun to be utilized. The manipulation of endogenous hormone levels via the use of transgenic plants transformed with bacterial genes ( iaaM and ipt from Agrobacterium tumefaciens and iaaL from Pseudomonas syringae pv. savastanoi ) has demonstrated powerful effects of auxin and cytokinin on axillary bud outgrowth. Also, possible auxin and cytokinin involvement of rolB and C genes from Agrobacterium rhizogenes whose activity is associated with reduced apical dominance in dicotyledons has received considerable attention. The characterization of unique mRNAs and proteins in non-growing and growing lateral buds before and after apical dominance release is helping to lay the groundwork for the elucidation of signal transduction and cell cycle regulation in this response. The use of auxin-deficient, and auxin/ethylene-resistant mutants has provided another approach for analyzing the role of these hormones. The presumed eventual employment of molecular assay systems (SAUR/GH3 promoters fused with GUS reporter gene) which are presently being developed for analyzing auxin localized in lateral buds will hopefully provide a critical test for the direct auxin inhibition hypothesis. 相似文献