声波刺激对猕猴桃愈伤组织ATP含量的影响

采用单因子实验设计,分别先固定作为交变应力的声波的频率或强度这两个参数中的一个,而改变另一个指标的值,用声波刺激木本植物中华猕猴桃(Actinidiachinensis)茎段的愈伤组织,并测定对比声波处理前后其ATP含量及变化情况。实验结果表明,声波对猕猴桃愈伤组织ATP的含量有着比较明显的增强或抑制的双重效应,适度的声场刺激将有利于提高植物的能量代谢水平,其中,最适的声波频率为1000Hz,最适声强为100dB左右 。     

机械振荡对猕猴桃愈伤组织ATP含量的影响

采用不同频率的往复机械振荡,以木质藤本植物中华猕猴桃(Actinidia chinensis)茎段的愈伤组织为实验材料,测定．ATP含量的变化,并通过与对照组(CK)相应值的比较,研究振荡刺激对植物能量代谢的影响。结果表明,机械振荡对猕猴桃愈伤组织ATP的含量有着比较明显的增强或抑制的双重效应,适度的振荡刺激将有利于提高植物的能量代谢水平,促进植物的生长发育,其中最适的振荡频率为3Hz左右。还从细胞和分子生物学的角度对环境应力影响植物能量代谢的可能机理进行了探讨。     

声波刺激对菊花愈伤组织膜脂物理状态和膜脂代谢的影响

以蔗糖梯度法纯化的菊花 (Dendranthemamorifolium (Ramat.)Tzvel.)愈伤组织质膜微囊为材料 ,研究了声波刺激下质膜膜脂代谢和物理状态的变化。结果表明 ,一定强度 (10 0dB)和频率 (10 0 0Hz)的声波刺激使质膜磷酸二脂含量和二苯己三烯 (DPH)荧光偏振值降低 ,质膜光散射值、MC5 40荧光强度和磷酸单脂含量增加。表明一定强度和频率的声波刺激使质膜变疏松 ,膜的流动性增加 ,膜表面电荷密度和疏水性降低 ,膜脂合成代谢增加 ,分解代谢减弱。由此可见 ,膜脂物理状态和膜脂代谢对声波刺激极为敏感。     

声波刺激对菊花愈伤组织膜脂物理状态和膜脂代谢的影响

以蔗糖梯度法纯化的菊花(Dendranthema morifolium (Ramat.) Tzvel.)愈伤组织质膜微囊为材料,研究了声波刺激下质膜膜脂代谢和物理状态的变化.结果表明, 一定强度(100 dB)和频率(1 000 Hz)的声波刺激使质膜磷酸二脂含量和二苯己三烯(DPH)荧光偏振值降低,质膜光散射值、MC540荧光强度和磷酸单脂含量增加.表明一定强度和频率的声波刺激使质膜变疏松,膜的流动性增加,膜表面电荷密度和疏水性降低,膜脂合成代谢增加,分解代谢减弱.由此可见,膜脂物理状态和膜脂代谢对声波刺激极为敏感.     

三七组织培养的建立

三七的根、块根、根茎、茎、叶柄、叶和花蕾等各部位诱导出愈伤组织。当这些愈伤组织无性系继代培养到第5代后进行了药用成分皂苷薄层层析的初步鉴定。结果表明三七愈伤组织中含有皂苷的主要成分Rg₁ Rb₁和Rh₁。粗总皂昔含量比原植物高,为干重的5．37％(原植物为干重的4．25％),粗皂苷元含量也高于原植物。愈伤组织的生长速率是54．0mg干重／L／day。各部位愈伤组织中以茎愈伤组织较好,无论干重增加、生长速率、粗总皂苷含量和产率、粗皂苷元含量还是皂甙组成上均比其他部位愈伤组织优越。对于茎愈伤组织的生长,基本培养基以Ms培养基较好,最适pH值为5．8,最适温度为26℃。光照对生长稍有促进但不显著。     

交变应力作用下烟草细胞热力学相行为的研究

研究了交变应力对烟草愈伤组织细胞的影响, 采用本实验室研制的强声波发生装置来产生交变应力场, 并利用差式扫描量热仪（ＤＳＣ） 研究了不同强度和频率的交变应力作用后烟草细胞热力学相行为的变化。研究结果表明：交变应力的影响与应力的频率和强度密切相关,一定频率和强度范围内的交变应力能使得植物细胞的相变温度有明显的降低, 而过高频率的应力刺激则会使细胞相变温度升高。细胞热力学相变反映了细胞壁膜的流动性,相变温度变低表明细胞壁膜的流动性增强, 这必然为细胞的生长和分裂提供了便利的条件。 因此, 对于从细胞和分子水平研究交变应力对植物生长、发育的影响及其作用机理是一个很有意义的尝试     

CPA对中华猕猴桃离体培养分化和POD活性的影响

CPA(4-chlorophenoxyacetic acid,简称 CPA,其结构类似2,4-D,据报道能促进黑绿豆,豌豆等植物长寿命 mRNA 的转译,刺激萌发种子的下胚轴膨大,进而诱导侧根和愈伤组织。为了进一步研究 CPA 对离体培养植物的调控作用以及 CPA 与其他激素的相互调节作用和效应,我们以中华猕猴桃无菌苗为材料进行了组织培养及有关生理生化分析,为 CPA 应用于离体培养提供实验指标。     

机械振荡对猕猴桃试管苗根系发育的影响

目的:研究外界环境应力刺激对木本植物幼苗根系发育的生物学效应。方法:通过模拟机械振荡刺激中华猕猴桃的试管苗。结果:适度的机械振荡(频率2～3 Hz)可促进猕猴桃试管苗根系的生长发育,根系质膜的通透性降低,根尖活力以及根系总长、分根数等指标明显增加;但当振动强度超过一定值(4Hz)后,根系活力的增强效应就受到明显的抑制。结论:植物根系发育对外界应力刺激有较显著的双向效应;从细胞和分子生物学水平探讨了环境应力影响试管苗根系发育可能的内在机制。     

软枣猕猴桃悬浮细胞系的建立及其影响因素

以软枣猕猴桃(Actinidia arguta Planch)叶片为试材,以MS为基本培养基,附加生长素(2.4-D、NAA)和玉米素(ZT)成功地诱导出愈伤组织,结果表明:软枣猕猴桃叶片在MS+ZT 1mg/1+2.4-D3mg/1的情况下能诱导出适合于建立悬浮细胞系的愈伤组织。并研究了愈伤组织生长年龄、激素浓度、肌醇和蔗糖浓度四个方面对建立悬浮细胞系的影响。表明愈伤组织以生长10天时接种活细胞率最高;以MS培养基附加ZT1mg/1+2.4-D3mg/1较好;肌醇以200mg/1圆形细胞频率最高;蔗糖以5%最适。     

尾巨桉不同类型愈伤组织抗性相关酶活性差异与不定芽分化关系研究

本实验以尾巨桉无性系32-29无菌苗的茎段为外植体,应用不同植物生物调节剂处理,诱导愈伤组织形成,分别测量4种类型愈伤组织的蛋白质含量及过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)等保护酶的指标活性,比较不同愈伤组织的酶活性强弱与不定芽分化的关系。结果表明:不同处理间愈伤组织诱导率差异达到极显著水平,且不同愈伤组织蛋白质含量及3种酶活力差异明显,POD、SOD活力高的愈伤组织不定芽诱导率也高,而PPO含量高的愈伤组织诱芽率低。     

植物对环境应力刺激的生物学效应

植物生长在自然环境中由于其“不动性”而不可避免地要受到各种环境应力的刺激,应力－生长关系一直是生物学家和物理学家所关心的课题,是生物力学的灵魂。很多研究已经表明外界应力作用对植物的生长发育有着重要的影响。本综述了国内外关于应力对植物组织所引起的生物学效应,首先论述了环境应力所引起的宏观生物学效应,随后重点论述了环境应力所引起的生物学效应在细胞和分子水平上的研究,其中包括单个细胞的加载、电磁场、微     

Responses to environmental stresses in woody plants: key to survive and longevity

Environmental stresses have adverse effects on plant growth and productivity, and are predicted to become more severe and widespread in decades to come. Especially, prolonged and repeated severe stresses affecting growth and development would bring down long-lasting effects in woody plants as a result of its long-term growth period. To counteract these effects, trees have evolved specific mechanisms for acclimation and tolerance to environmental stresses. Plant growth and development are regulated by the integration of many environmental and endogenous signals including plant hormones. Acclimation of land plants to environmental stresses is controlled by molecular cascades, also involving cross-talk with other stresses and plant hormone signaling mechanisms. This review focuses on recent studies on molecular mechanisms of abiotic stress responses in woody plants, functions of plant hormones in wood formation, and the interconnection of cell wall biosynthesis and the mechanisms shown above. Understanding of these mechanisms in depth should shed light on the factors for improvement of woody plants to overcome severe environmental stress conditions.     

植物生长调节剂对南方红豆杉愈伤组织培养和紫杉醇合成的影响

通过不同种类和水平植物生长调节剂对南方红豆杉(Taxus chinensisvar.mairei)愈伤组织诱导、生长和紫杉醇合成能力影响的研究发现:诱导培养初期,以无植物生长调节剂的MS为基本培养基,在附加不同植物生长调节剂组合作用下愈伤组织产生的时间和生长、在相同植物生长调节剂组合作用下不同外植体愈伤组织的产生时间和生长均表现出较显著差异,2,4-D/NAA高于0.4时,不利于南方红豆杉愈伤组织的诱导。转换到附加不同植物生长调节剂组合的B5培养基上后,随培养继代次数的增加,生长差异逐渐缩小,直至不显著,表明参考不同文献报道最优配方所设计的各植物生长调节剂组合对南方红豆杉愈伤组织的生长均较适宜,有利南方红豆杉愈伤组织生长的植物生长调节剂优化组合没有唯一性。但不同调节剂组合作用下的同源愈伤组织中、相同调节剂作用下不同源愈伤组织中紫杉醇含量均存在着极显著差异,适当水平(2 mg/L)的2,4-D单用,或与适当水平的KT、6-BA、KT GA配合使用,对南方红豆杉愈伤组织紫杉醇的合成较有利,NAA则不太有利,幼茎和叶愈伤组织产紫杉醇的水平较其它愈伤组织为高。     

钒、汞胁迫对菜心幼苗生理生化特性的影响

通过水培实验研究了钒(V)、汞(Hg)单一和复合胁迫对四九黄菜心幼苗生理生化特性的影响。结果表明:随着胁迫强度的增加,丙二醛(MDA)含量和细胞膜透性明显上升,与对照相比,MDA含量和细胞膜透性分别增加了8.4%～271.5%和22.4%～145.6%;叶绿素含量、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性均呈先上升后下降的趋势;重金属浓度较低时,3种保护酶均有较好的协同效应,表现出较强的自我调节能力;重金属浓度较高时,叶绿素含量和3种酶的活性呈下降趋势,表明在逆境环境因子下,植物的生理特征发生变化,酶活性受到抑制;V、Hg复合胁迫对蔬菜幼苗的毒害作用大于同水平单一胁迫效应。     

Melatonin-related mitochondrial respiration responses are associated with growth promotion and cold tolerance in plants

Melatonin has the ability to improve plant growth and strengthened plant tolerance to environmental stresses; however, the effects of melatonin on mitochondrial respiration in plants and the underlying biochemical and molecular mechanisms are still unclear. The objective of the study is to determine possible effects of melatonin on mitochondrial respiration and energy efficiency in maize leaves grown under optimum temperature and cold stress and to reveal the relationship between melatonin-induced possible alterations in mitochondrial respiration and cold tolerance. Melatonin and cold stress, alone and in combination, caused significant increases in activities and gene expressions of pyruvate dehydrogenase, citrate synthase, and malate dehydrogenase, indicating an acceleration in the rate of tricarboxylic acid cycle. Total mitochondrial respiration rate, cytochrome pathway rate, and alternative respiration rate were increased by the application of melatonin and/or cold stress. Similarly, gene expression and protein levels of cytochrome oxidase and alternative oxidase were also enhanced by melatonin and/or cold stress. The highest values for all these parameters were obtained from the seedlings treated with the combined application of melatonin and cold stress. The activity and gene expression of ATP synthase and ATP concentration were augmented by melatonin under control and cold stress. On the other hand, cold stress reduced markedly plant growth parameters, including root length, plant height, leaf surface area, and chlorophyll content and increased the content of reactive oxygen species (ROS), including superoxide anion and hydrogen peroxide and oxidative damage, including malondialdehyde content and electrolyte leakage level; however, melatonin significantly promoted the plant growth parameters and reduced ROS content and oxidative damage under control and cold stress. These data revealed that melatonin-induced growth promotion and cold tolerance in maize is associated with its modulating effect on mitochondrial respiration.     

Phenotypic plasticity and genetic differentiation of quantitative traits in genotypes of Leymus chinensis北大核心CSCD

Aims Adaptation mechanisms of plants to environment can be classified as genetic differentiation and phenotypic plasticity (environmental modification). The strategy and mechanism of plant adaptation is a hot topic in the field of evolutionary ecology. Leymus chinensis is one of constructive species in the Nei Mongol grassland. Particularly, Leymus chinensis is a rhizomatous and clonally reproductive grass, a genotype that can play an important role in the community. In this study, we aimed to (1) investigate the phenotypic plasticity of L. chinensis under different conditions, and (2) test the genetic differentiation and reaction norms (the relationship between the environment and the phenotype of an individual or a group of individuals) under four environmental conditions among different genotypes of L. chinensis. Methods Ten genotypes of L. chinensis were randomly selected. Under the control condition, we studied the effects of genotype, defoliation, drought and their interactions on 11 quantitative traits of growth (8 traits including photochemical efficiency of photosystem II, maximum net photosynthetic rate, transpiration rate, specific leaf area, relative growth rate, the number of tillers increased, aboveground and underground biomass growth), defense (total phenol concentration of leaf) and tolerance (non-structural carbohydrate content of root, root/shoot ratio) of L. chinensis. We studied the phenotypic plasticity, genetic differentiation and reaction norms mainly through tested the effect of environment and genotype on these traits. Important findings First, all 11 traits showed obvious phenotypic plasticity (i.e., significant effect of drought, defoliation and their interactions). The expression of 10 genotypes of L. chinensis was divergent under different environmental conditions. Interactions of genotype and environment significantly affected the maximum net photosynthetic rate, transpiration rate, specific leaf area, relative growth rate, total phenolic concentration of leaf, and total non-structural carbohydrate content of root. This indicated that the phenotypic plasticity of these five traits exhibited genetic differentiation. Second, the increase of number of tillers, belowground biomass and non-structural carbohydrate content of root did not show genetic differentiation under the same condition. The other eight traits showed significantly genetic differentiation, and the heritabilities (H2) of six traits related to growth were higher than 0.5. The leaf total phenol concentration and root/shoot ratio showed genetically differentiation only under the drought and defoliation condition, with the heritabilities being 0.145 and 0.201, respectively. These results explained why L. chinensis widely distributed in the Nei Mongol grassland, and provided genetic and environmental basis for related application and species conservation in this grassland ecosystem.     

盐旱交叉胁迫对柽柳幼苗生长及生理生化特性的影响

以3年生柽柳为材料,采用盆栽实验测定分析不同盐旱交叉胁迫下柽柳的生长状况、光合色素含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性及丙二醛(MDA)含量,以阐明盐旱交叉胁迫对柽柳幼苗生长及生理生化特性的影响。结果显示:(1)盐胁迫对柽柳生长影响大于干旱胁迫,茎叶对盐旱胁迫的敏感性高于根系部分;随着盐胁迫的加剧,柽柳株高、基径以及干物质量均降低。(2)随盐旱胁迫的加剧,柽柳幼苗叶片光合色素含量先升高后降低,主导影响因子由干旱胁迫转为盐胁迫;重度盐胁迫下,叶绿素a、b下降明显。(3)中度干旱胁迫下,SOD和POD活性随盐胁迫的增强先降低后升高;随盐旱胁迫的加剧,SOD和POD活性逐渐减弱。(4)适度的盐旱胁迫能降低幼苗MDA含量,但重度干旱、轻中度盐分胁迫下MDA含量较高。研究发现,柽柳能通过调整自身生长和生理生化特性来提高其对逆境适应能力,表现出较强的抗旱耐盐性;盐旱胁迫下柽柳表现出一定的交叉适应性,适度的干旱胁迫能增强柽柳的耐盐能力。     

盐肤木体细胞胚胎发生及植株再生

以盐肤木(Rhus chinensis Mill.)幼胚为外植体,研究不同植物生长调节剂组合对其愈伤组织诱导及体细胞胚胎发生的影响,以建立盐肤木体细胞胚胎发生及植株再生体系。结果表明,最适愈伤组织诱导培养基为MS+6-BA 0.2 mg/L+2,4-D 1.0 mg/L,诱导率为84.57%,诱导出的初代愈伤组织白色或淡黄色,质地疏松,表面光滑,为非胚性愈伤。初代愈伤组织转移到1/2 MS+6-BA 2 mg/L+NAA 0.5 mg/L培养基上培养1个月后,长出淡黄色质地紧密的胚性愈伤组织,诱导率高达100%,在此培养基上胚性愈伤组织增殖倍数为854.73%。所获得的胚性愈伤组织转接到1/2 MS+6-BA 2 mg/L+NAA 0.5 mg/L+蔗糖4%的培养基上培养1个月后可诱导体细胞胚胎发生,诱导率可达32.67%。诱导得到的体细胞胚胎经历球形胚、心形胚、鱼雷胚、子叶胚进一步分化发育成苗。无菌苗炼苗后栽种到泥炭土∶蛭石∶珍珠岩为2∶1∶1的生长基质上,能100%稳定成活。经过细胞学观察分析,体细胞胚的发育与合子胚相似。