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细胞分裂素在植物抗逆和延衰中的作用 总被引:44,自引:0,他引:44
本文综述了细胞分裂素类物质的种类、分布和在植物抗水分胁迫、低温冷害、病虫害等方面的作用以及在延缓果实、叶片、切花等衰老中的效果,讨论了其生理机制、细胞分裂素与其它植物激素的相互关系,并提出了有关细胞分裂素类物质作用机理中值得深入研究的若干问题,如嘌呤型与苯基脲型细胞分裂素的作用特点,细胞分裂素与生长素、脱落酸的协调作用和拮抗作用细胞分裂素的从头合成途径和tRNA途径等。 相似文献
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细胞分裂素对植物衰老的延缓作用 总被引:5,自引:0,他引:5
细胞分裂素是一类重要的植物激素,它可在一定程度上延缓植物的衰老。主要从3个方面综述了细胞分裂素与植物衰老之间的关系,即:(1)植物衰老过程中内源细胞分裂素含量变化;(2)外源细胞分裂素的影响;(3)转入与细胞分裂素的合成、降解相关的基因对植物衰老产生的影响。此外,还从细胞分裂素与糖、与脂质氧化反应以及与其它植物激素的关系方面探讨了细胞分裂素在延缓植物衰老中的作用机理。 相似文献
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细胞分裂素在维持紫萍叶状体生命中的重要作用 总被引:3,自引:0,他引:3
将无根和囊的紫萍(Spirodela polyrrhiza)P143品系半叶状体分别放在含有和不含6-苄基嘌呤的培养液上于长日照条件下培养。在不含6-BA的培养液上培养4d以后,半叶状体开始失绿,光合能力降低;第12天时,半叶状体已接近死亡。但是,培养在含有6-BA的培养液上的半叶状体干重、叶绿素和可溶性蛋白质含量、希尔反应活力、核酮糖-1,5-二磷酸羧化酶/加氧酶的小亚基和其编码基因rbcS mRNA水平显著增加。这些6-BA处理过的半叶状体平均寿命可达80d,几乎等同于完整植物体上叶状体的寿命,因此提出细胞分裂素对于紫萍叶状体生物学功能的维持是必需的。 相似文献
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细胞分裂素类物质在植物组织培养中的作用机制 总被引:55,自引:0,他引:55
论述了细胞分裂素类物质及新近正被广泛应用的具有细胞分裂素活性的苯基脲衍生物在植物组织培养过程中的作用及其机理。 相似文献
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气液色谱法定量测定植物细胞分裂素 总被引:2,自引:0,他引:2
自从Most发明了三甲基硅烷制备衍生物(以下简称TMS)方法以来,国外有许多利用该法测定细胞分裂素的报告。Horgan利用TMS衍生化方法,检测出枫树韧皮部中的玉米素核苷;Upper等用GLC配FID检测出5ng的CTK-TMS衍生物。目前,国外对细胞分裂素作定性分析测定经常采用该衍生化方法,但用于定量测 相似文献
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Delayed Leaf Senescence in Tobacco Plants Transformed with tmr,a Gene for Cytokinin Production in Agrobacterium 总被引:9,自引:0,他引:9 下载免费PDF全文
The aim of this study was to investigate whether enhanced levels of endogenous cytokinins could influence plant development, particularly leaf senescence. Tobacco plants were transformed with the Agrobacterium tumefaciens gene tmr, under the control of the soybean heat shock promoter HS6871. This gene encodes the enzyme isopentenyl transferase, which catalyzes the initial step in cytokinin biosynthesis. After heat shock, the cytokinin level increased greatly and the level of tmr mRNA, undetectable at 20[deg]C, rose and remained high for up to 8 hours. The levels of cytokinin and tmr mRNA were substantially lower by 24 hours. Transformed plants grown at 20[deg]C were shorter, had larger side shoots, and remained green for longer than untransformed plants. The differences were more pronounced after several heat shocks of whole plants or defined areas of leaves. Our results demonstrated that plant morphology and leaf senescence can be manipulated by changing the endogenous level of cytokinins. 相似文献
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Ethylene and Cytokinin in the Control of Senescence in Detached Leaves of Arabidopsis thaliana eti-5Mutant and Wild-Type Plants 总被引:1,自引:0,他引:1
Kudryakova N. V. Burkhanova E. A. Rakitin V. Yu. Yakovleva L. A. Smith A. Hall M. A. Kulaeva O. N. 《Russian Journal of Plant Physiology》2001,48(5):624-627
We studied the effects of cytokinin benzyladenine (BA) and ethylene on the senescence in the dark of detached leaves of Arabidopsis thaliana(L.) Heynh wild-type plants and theeti-5mutant, which was described in the literature as the ethylene-insensitive one. Leaf senescence was assessed from a decrease in the chlorophyll content. The content of endogenous cytokinins (zeatin and zeatin riboside) was estimated by the ELISA technique. We demonstrated that the content of endogenous cytokinins in the leaves of the three-week-old eti-5mutants exceeded that of the wild-type leaves by an order of magnitude; in the five-week-old mutants, by several times; and in the seven-week-old plants, the difference became insignificant. Due to the excess of endogenous cytokinins in the three–five-week-old mutant leaves, their senescence in the dark was retarded and exogenous cytokinin affected these leaves to a lesser extent. The seven-week-old mutant and the wild-type leaves, which contained practically similar amounts of endogenous cytokinins, did not differ in these indices. Thus, the level of endogenous cytokinins determined the rate of senescence and the leaf response to cytokinin treatment. Ethylene accelerated the senescence of detached wild-type leaves. Ethylene action increased with increasing its concentration from 0.1 to 100 l/l. BA (10–6M) suppressed ethylene action. Similar data were obtained for the eti-5mutant leaves. We therefore suggest that the mutant leaves comprised the pathways of the ethylene signal reception and transduction, which provided for the acceleration of their senescence. 相似文献
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Cytokinin Biochemistry in Relation to Leaf Senescence: IV. Cytokinin Metabolism in Soybean Explants 下载免费PDF全文
Singh S Letham DS Jameson PE Zhang R Parker CW Bandenoch-Jones J Noodén LD 《Plant physiology》1988,88(3):788-794
When [3H]dihydrozeatin riboside and [3H]zeatin riboside were supplied to soybean (Glycine max L.) explants (comprising one leaf, associated pods, and subtending stem) via the xylem at mid to late podfill, 0.1% of the supplied 3H was extracted from the seeds. The distribution of 3H in the explants was similar to that bound previously following uptake of [3H]zeatin riboside at earlier stages of pod development. Metabolites formed in the explants from 3H-labeled zeatin, zeatin riboside, and dihydrozeatin riboside were identified and related to the endogenous cytokinins shown to be present. When zeatin riboside and zeatin were supplied for 1 hour, zeatin nucleotide was the principal metabolite formed and this appeared to be the precursor of the other metabolites detected subsequently. Explants supplied with zeatin riboside or dihydrozeatin riboside for 1 hour, and then transferred to water for 20 to 24 hours, yielded leaf blades in which the main metabolites were O-glucosyldihydrozeatin, adenosine, and adenine. The metabolism of zeatin riboside in blades of explants at pre-podfill, early podfill, and mid to late podfill did not differ appreciably. The results are discussed in relation to leaf senescence and seed development. 相似文献
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Effect of Disbudding on Root Cytokinin Export and Leaf Senescence in Tomato and Tobacco 总被引:2,自引:0,他引:2
Bud removal and decapitation (disbudding) of plants of tomato(Lycopersicon esculentum Miller) and tobacco (Nicotiana tabacumL.) resulted in an increase in both the concentration and thetotal flux of cytokinin in bleeding xylem sap. There was a retardationin the rate of chlorophyll loss from leaves of disbudded plantsof both species. Ultrastructural examination of the chloroplastsof disbudded tomato plants revealed a maintenance of chloroplastintegrity, compared with chloroplasts from control plants. Itis suggested that the delaying of leaf senescence observed indisbudded plants is due to an increased availability of cytokininto these leaves. 相似文献
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Changes in Endogenous Cytokinin Levels During Abscission and Senescence of Streptocarpus Leaves 总被引:3,自引:0,他引:3
The cytokinin levels of butanol and aqueous extracts of proximalportions of Streptocarpus leaves showed very little change duringthe summer and early autumn months, whereas those of the distalportions changed markedly. These changes appear to be closelyrelated to the formation of abscission layers and the subsequentsenescence of the distal part of the leaves. It is postulatedthat the increase in butanol-soluble cytokinins during Januarymay induce abscission, while the decrease in February appearsto be directly related to senescence of the distal portionsof the leaves. 相似文献