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水分胁迫积累的ABA诱导抗氧化防护系统的信号级联 总被引:3,自引:0,他引:3
水分胁迫是限制植物生长发育的主要胁迫因子之一。植物通过感受刺激,产生和传递信号、启动多种防御机制对水分胁迫做出响应和适应。脱落酸(ABA)作为一种重要的植物体内胁迫激素,参与了许多这样的反应。研究表明,ABA增强植物水分胁迫的忍耐力与ABA诱导的抗氧化剂防护系统有关;且细胞溶质Ca2 ([Ca2 ]i)、活性氧(ROS)等许多第二信使参与了ABA诱导的信号转导过程。本文就这些信号分子在水分胁迫积累的内源ABA诱导的抗氧化剂防护系统中的作用作一综述。 相似文献
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水分胁迫下植物体内OH的产生与细胞的氧化损伤 总被引:26,自引:0,他引:26
蒋明义 《Acta Botanica Sinica》1999,41(3):229-234
干旱是植物组织的一种重要的胁迫因子。它能干扰植物细胞中活性氧产生与清除的平衡,导致植物细胞遭受氧化胁迫。过去十多年来,人们对水分胁迫下植物体内活性氧的产生、活性氧对植物的伤害及植物保护系统的作用进行了大量的研究,取得了明显的进展[1~4]。然而,水分... 相似文献
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脱落酸与植物细胞的抗氧化防护 总被引:29,自引:0,他引:29
水分胁迫是一种影响植物生长发育、限制植物产量的重要胁迫因子。植物能够通过感知刺激、产生和传导信号、启动各种防护机制来响应与适应水分胁迫。植物激素脱落酸(ABA)作为一种胁迫信号,在调节植物对水分胁迫的反应中起着重要的作用。ABA不仅能诱导气孔关闭,而且能诱导编码耐脱水蛋白的基因表达。正在增加的证据显示,ABA增强水分胁迫的耐性与其诱导抗氧化防护系统有关。本文综述了ABA在诱导活性氧(ROS)产生、调节抗氧化酶基因表达以及增强抗氧化防护系统方面的作用,着重讨论了在ABA诱导的抗氧化防护过程中Ca2 、NADPH氧化酶与ROS之间的交谈机制。 相似文献
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水分亏缺诱导的氧化胁迫和植物的抗氧化作用 总被引:150,自引:0,他引:150
简要介绍了水分胁迫下植物体内O2、H2O2、OH及1O2等活性氧的产生及其检测方法,评述了水分胁迫下植物内源抗氧化系统的作用,并对有关方面的研究作了展望。 相似文献
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水分胁迫是一种影响植物生长发育、限制植物产量的重要胁迫因子.植物能够通过感知刺激、产生和传导信号、启动各种防护机制来响应与适应水分胁迫.植物激素脱落酸(ABA)作为一种胁迫信号,在调节植物对水分胁迫的反应中起着重要的作用.ABA不仅能诱导气孔关闭,而且能诱导编码耐脱水蛋白的基因表达.正在增加的证据显示,ABA增强水分胁迫的耐性与其诱导抗氧化防护系统有关.本文综述了ABA在诱导活性氧(ROS)产生、调节抗氧化酶基因表达以及增强抗氧化防护系统方面的作用,着重讨论了在ABA诱导的抗氧化防护过程中Ca2 、NADPH氧化酶与ROS之间的交谈机制. 相似文献
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植物对水分亏缺的某些生化反应 总被引:29,自引:1,他引:28
就植物对水分亏缺的某些生化反应的研究进展,尤其是积累溶质的功能、与耐水分胁迫有关的因素、盐生植物和甜土植物对水分胁迫反应的生化差异,以及植物耐水分胁迫基因工程的研究策略和动态进行了综述。 相似文献
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盐胁迫对星星草幼苗光合特性的影响 总被引:9,自引:4,他引:9
对松嫩碱化草地上人工种植生长一至三年的星星草和自然生长的天然星星草的光合蒸腾特性的季节变化进行了测定。星星草光合速率的季节变化是单峰曲线,抽穗期光合速率最大。星星草的蒸腾速率则随生育期进程逐渐减小,但单位面积草地上星星草群体蒸腾速率的季节变化为单峰曲线,一年生、二年生和三年生星星草的最大值在开花期,而天然星星草则在抽穗期。星星草水分利用效率的季节变化也是单峰曲线,峰值均在抽穗期。 相似文献
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鱼类遭受低温胁迫易产生分子、细胞和组织损伤, 甚至导致个体死亡。鱼类机体细胞感受到低温刺激后, 通过多种应激通路将低温信号传递至细胞核, 启动低温应激反应, 建立新的胞内稳态, 从而增强抗寒能力。低温可激活鱼类内分泌系统释放皮质醇和甲状腺素等激素, 调控代谢、渗透压和免疫反应, 最终引起生理和行为变化。鱼类低温应激反应受表观遗传修饰、转录和翻译、前体RNA可变剪接和蛋白质翻译后修饰等多层级的复杂调控。目前, 采用多组学技术已经鉴定到大量与低温响应相关的效应基因和调控通路。研究表明, 能量代谢和抗氧化应激反应在鱼类抗寒能力的建成起着重要作用。其他环境因子(如低氧和盐度)及鱼体生理状态(如饥饿和营养)也影响鱼类对低温刺激的反应和抗寒能力。鉴定抗寒相关的分子标记并解析其关联基因的作用机制对鱼类的抗寒育种具有重要意义。 相似文献
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FLUCTUATING ASYMMETRY: AN EPIGENETIC MEASURE OF STRESS 总被引:11,自引:0,他引:11
P. A. PARSONS 《Biological reviews of the Cambridge Philosophical Society》1990,65(2):131-145
(1) Fluctuating asymmetry (FA) is a useful trait for monitoring stress in the laboratory and in natural environments.
(2) Both genomic and environmental changes can increase FA which represents a deterioration in developmental homeostasis apparent in adult morphology. Genetic perturbations include intense directional selection and certain specific genes. Environmental perturbations include temperature extremes in particular, protein deprivation, audiogenic stress, and exposure to pollutants.
(3) There is a negative association between FA and heterozygosity in a range of taxa especially fish, a result consistent with FA being a measure of fitness.
(4) Scattered reports on non-experimental populations are consistent with experiments under controlled laboratory conditions. FA tends to increase as habitats become ecologically marginal; this includes exposure to environmental toxicants.
(5) In our own species, FA of an increasing range of traits has been related to both environmental and genomic stress.
(6) Domestication increases FA of the strength of homologous long bones of vertebrate species due to a relaxation of natural selection.
(7) FA levels are paralleled by the incidence of skeletal abnormalities in stressful environments.
(8) Increased FA is a reflection of poorer developmental homeostasis at the molecular, chromosomal and epigenetic levels. 相似文献
(2) Both genomic and environmental changes can increase FA which represents a deterioration in developmental homeostasis apparent in adult morphology. Genetic perturbations include intense directional selection and certain specific genes. Environmental perturbations include temperature extremes in particular, protein deprivation, audiogenic stress, and exposure to pollutants.
(3) There is a negative association between FA and heterozygosity in a range of taxa especially fish, a result consistent with FA being a measure of fitness.
(4) Scattered reports on non-experimental populations are consistent with experiments under controlled laboratory conditions. FA tends to increase as habitats become ecologically marginal; this includes exposure to environmental toxicants.
(5) In our own species, FA of an increasing range of traits has been related to both environmental and genomic stress.
(6) Domestication increases FA of the strength of homologous long bones of vertebrate species due to a relaxation of natural selection.
(7) FA levels are paralleled by the incidence of skeletal abnormalities in stressful environments.
(8) Increased FA is a reflection of poorer developmental homeostasis at the molecular, chromosomal and epigenetic levels. 相似文献
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水分胁迫和胁迫后复水对玉米叶片生长速率的影响 总被引:9,自引:0,他引:9
玉米叶片延伸速率(LER)对水分状况的变化很敏感。快速干旱处理,水分消耗迅速,LER从最大到零需5h,叶水势改变0.5~0.6 MPa,缓慢干旱处理,水分消耗较慢,LER从最大到零需20h,叶水势改变1 MPa。缓慢干旱植株叶片成熟部位的渗透势,在任何LER下,均比快速干旱叶片更负。LER为零时,快速干旱叶渗透势为-1.3 MPa,缓慢干旱为一1.6MPa左右。短时间水分胁迫后复水,LER迅速增加,有部分补偿前期胁迫减少的生长量能力;长时间水分胁迫后复水,LER在6 h内不可能恢复到正常水平。 相似文献
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We earlier demonstrated that hsp68 is deficiently induced upon stress in the glucocorticoid-resistant, dedifferentiated Reuber rat hepatoma clone 2 cells, but is strongly activated in the differentiated, glucocorticoid-sensitive Faza 967 cells from which clone 2 was derived. We used the two cell types to address the questions whether hsp68 is specifically involved in the development of thermotolerance and/or thermoresistance or drug resistance. Our experiments show that clone 2 cells were not protected from the killing effect of heat by pretreatment with sodium arsenite, whereas Faza 967 cells were. These results strongly suggest a role of hsp68 in the development of thermotolerance in hepatoma cells. Stable heat-resistant variants of clone 2 cells were also isolated, where an increased basal expression of several hsps was observed together with the (at least partial) restoration of the heat-inducibility of hsp68. These results suggest that several hsps are needed to protect the critical biological processes at high temperature. The heat-resistant hepatoma cells also became resistant to several anticancer drugs. The multidrug resistance of the hepatoma variants correlates with the overexpression of the plasma membrane P-glycoprotein. Our results showing that severely stressed hepatoma cells overexpressed the mdr gene(s) raise the possibility that the P-gp may participate in protection against environmental stress such as heat. 相似文献
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抵抗风力胁迫是荒漠藻类适应干旱区环境的重要生物学机制,也是藻结皮能够拓殖流沙的必要条件之一,但有关藻类对风力胁迫的响应机理国内外尚无研究报道。以具鞘微鞘藻(Microcoleus vaginatus Gom.)人工结皮为实验对象,研究了不同强度风力吹蚀对结皮含水量、藻类活力、生物量、及其光合活性的影响。结果表明:不论低于当地起沙风(3m/s)还是高于起沙风(5m/s和7m/s)的风力吹蚀,结皮中藻类生物量均明显下降,而且结皮生物量的变化与风速大小和吹蚀时间呈线性关系(y=14.78+0.035a-1.48b,a风速,b时间,r2=0.79)。进一步分析发现,风力吹蚀后结皮中藻类活力并没有降低但主要光合色素和天线色素的含量普遍降低,叶绿素荧光(Fv/Fm)、表观电子传递速率(ETR)和净光合速率(Pn)明显下降,并且风速越大,降幅越大。这些结果说明风力胁迫对藻结皮生长和光合活性的影响主要是通过影响光合色素代谢合成和电子传递速率引起的,对其生命力没有明显影响。
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干旱胁迫对红松幼苗针叶超微结构的影响 总被引:3,自引:1,他引:2
在土壤逐渐失水和PEG溶液模拟的两种不同形式的干旱胁迫下,红松幼苗针叶细胞中叶绿体和线粒体超微结构的变化呈现出显著的差异。在土壤干旱胁迫下,叶绿体的片层结构发生严重的扭曲并在中央部分形成电子密度较高的黑色团块物质。PEG模拟的干旱胁迫下,叶绿体肿胀,空泡化明显,但在叶绿体的中央没有黑色团块物质的形成。在土壤干旱胁迫后,线粒体的膜结构仍然完整清晰,基质比胁迫前更为浓厚,而PEG溶液的干旱胁迫下,线粒体的数量增多,嵴明显减少,基质变得十分稀薄。可见两种不同方式的干旱胁迫处理下,细胞结构的损伤机制及损伤后产生的生理意义并不完全相同。 相似文献