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81.
J. Trémouillaux-Guiller H. Kodja J. C. Chénieux 《Plant Cell, Tissue and Organ Culture》1994,37(1):25-30
Protoplasts enzymatically isolated from cell line of Catharanthus roseus G. Don crown gall, were cultured at high density (105 P ml-1) in modified B5 liquid medium (Gamborg et al. 1976). In the absence of growth regulators C. roseus protoplasts were able to regenerate a cell-wall, divide and, subsequently, yield very numerous clones in the absence of growth regulators. After two weeks, the cultures were greatly diluted in order to obtain clones of single-cell origin. Most of the clones individually transferred onto solid medium can proliferate indefinitely, without growth regulators. Among analyzed clones, 90% were nopaline positive. Their ajmalicine and serpentine content was compared with that of the parental crown gall line, and was found to be low. The CR10 protoplasts were very easy to grow, they were an interesting model for the development of pure tumorous lines. Moreover, we found that the tumorous protoplasts were useful for cell fusion experiments or for the delicate culture of tree protoplasts.Abbreviations B5
Gamborg et al. (1976) medium
- 2,4-d
2,4-dichlorophenoxyacetic acid
- Kin
Kinetin
- NAA
naphthalene acetic acid
- BA
N6 (benzyl) adenine 相似文献
82.
Ch. Sasikala Ch. V. Ramana G. S. Prasad 《World journal of microbiology & biotechnology》1994,10(2):221-223
Production of H2 from glucose by an anoxygenic phototrophic bacterium (Rhodobacter sphaeroides), a cyanobacterium (Synechococcus cedrorum) and a heterotrophic bacterium (Pseudomonas fluorescens) was tested individually and in mixed cultures of various combinations in light. H2 production was maximal with a mixed culture of R. sphaeroides and P. fluorescens, which could be further enhanced by immobilization of the bacteria in alginate gel. Inhibition of H2 photoproduction was observed in a mixture of S. cedrorum and P. fluorescens and a co-culture of all the three organisms.Ch. Sasikala and Ch. V. Ramana are and G. S. Prasad was with the Microbial Biotechnology Laboratory, Department of Botany, Osmania University, Hyderabad-500 007, India. G. S. Prasad is now with the Microbial Type Culture Collection Centre (MTCC), IMTECH, Chandigar, India. 相似文献
83.
采用RNA斑点杂交分析,对21例人脑原发性胶质瘤和11例人脑膜瘤中p53,Rb和c-myc基因转录水平的表达进行研究.发现48.4%的肿瘤中p53基因表达减弱,21.9%的肿瘤中Rb基因表达减弱;71.9%的肿瘤中c-myc基因表达增强.在p53基因表达减弱的15例病例中有13例(80%)c-myc基因表达增强.结果表明,p53基因表达减弱和c-myc基因表达增强与人脑原发性肿瘤的发生有关. 相似文献
84.
岭南垛基果林湿地是珠三角地区典型的湿地类型之一,其对土壤碳汇的贡献值得关注。为探讨果林种植类型对土壤有机碳的影响,对广州垛基果林湿地内种植黄皮(Clausenalansium)(HP),龙眼(Dimocarpuslongan)(LY)、杨桃(Averrhoa carambola)(YT),龙眼和黄皮间种(LH),杨桃、龙眼和黄皮间种(YLH)共5种种植类型下的表层(0~20 cm)土壤碳组分进行研究。结果表明,不同的植被类型对土壤的总有机碳(SOC)、可溶性有机碳(DOC)、微生物生物量碳(MBC)、易氧化有机碳(ROC)、惰性碳(NLC)含量都有影响,LY的SOC含量最高(22.6 g/kg),显著高于YLH (P<0.05),且NLC含量显著高于LH和YLH (P<0.05)。NLC含量与土壤养分呈正相关,与土壤容重呈负相关。YT的MBC含量显著高于LY、HP、LH (P<0.05),且MBC/SOC显著高于HP、LY(P<0.05)。YLH模式下,土壤DOC含量和DOC/SOC显著高于其他植被类型(P<0.05)。LH的ROC/SOC显著高于HP和L... 相似文献
85.
本文运用Shannon—Wiener物种多样性指数、Simpson生态优势度指标以及边缘效应强度指数,对缙云山亚热带森林群落林窗的边缘效应现象进行了初步研究。29个林窗样地不同部位上述指标的测定表明用物种多样性指数拟合边缘效应测度通式,缙云山亚热带森林群落林窗的边缘效应强度值为1—3左右;而用生态优势度值拟合边缘效应强度测式,则上述边缘效应强度值为0.1一1.2左右。研究表明林窗边缘区由于边缘效应的作用有增大物种多样性的趋势。而林窗面积、所处坡向以及林窗所在的森林群落类型,都对处于不同发育阶段的林窗的边缘效应强度具有影响。在此基础上,本文对林窗边缘效应强度的变化规律、效应性质、测定意义以及对森林营造和优化管理上的作用进行了一定探讨。 相似文献
86.
87.
Astrocytes, neuronal perikarya and synaptosomes were prepared from rat cerebellum. Kinetics of high and low affinity uptake systems of glutamate and aspartate, nominal rates of14CO2 production from [U–14C]glutamate, [U–14C]aspartate and [1–14C]glutamate and activities of enzymes of glutamate metabolism were studied in these preparations. The rate of uptake and the nomial rate of production of14CO2 from these amino acids was higher in the astroglia than neuronal perikarya and synaptosomes. Activities of glutamine synthetase and glutamate dehydrogenase were higher in astrocytes than in neuronal perikarya and synaptosomes. Activities of glutaminase and glutamic acid decarboxylase were observed to be highest in neuronal perikarya and synaptosomes respectively. These results are in agreement with the postulates of theory of metabolic compartmentation of glutamate while others (presence of glutaminase in astrocytes and glutamine synthetase in synaptosomes) are not. Results of this study also indicated that (i) at high extracellular concentrations, glutamate/aspartate uptake may be predominantly into astrocytes while at low extracellular concentrations, it would be into neurons (ii) production of -ketoglutarate from glutamate is chiefly by way of transamination but not by oxidative deamination in these three preparations and (iii) there are topographical differences glutamate metabolism within the neurons. 相似文献
88.
Ch. Leuschner 《植被学杂志》1993,4(2):255-262
Abstract. The availability of maj or plant resources was investigated in three vegetation types that were assumed to represent different stages of a secondary succession on heathland on the Lüneburger Heide, northwestern Germany. Canopy transmission and absorption of photosynthetically active radiation (PAR), soil-water availability, and nutrient (Ca, K, Mg, N, P) availability were monitored with high spatial and temporal resolution in (1) a Calluna vulgaris heathland, (2) a pioneer birch-pine forest and (3) a late-successional oak-beech forest, situated close to each other on comparable geological substrate (diluvial). Mean fractional transmission of PAR during summer decreased from 0.48 in the heathland to 0.04 in the oak-beech forest while the fractional canopy absorption increased from 0.49 to 0.92. Soil-water availability as indicated by the soil-water potential, was significantly influenced by differential canopy interception loss and characteristic rooting patterns in the three vegetation types. Annual mean nutrient concentrations in the equilibrium soil solution were similar or, for some elements, increased from the heathland to the birch-pine and the oak-beech forest despite a growing demand. A marked increase was found for the total nutrient pools in the soil-organic layer between early and late successional vegetation types. On the poor glacial parent material, nutrient pools seem to be strongly dependent on stand productivity and litter production which increased with succession. Thus, for nutrients, facilitation seems to be important in this type of succession. 相似文献
89.
Xiaohe Li Xiaoyang Ma Yang Miao Jianwei Zhang Buri Xi Wenqi Li Qianyi Zhang Li Chen Yue Yang Hongli Li Luqing Wei Honggang Zhou Cheng Yang 《Journal of cellular and molecular medicine》2023,27(3):422-434
Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease that seriously threatens the health of patients. The pathogenesis of IPF is still unclear, and there is a lack of effective therapeutic drugs. Myofibroblasts are the main effector cells of IPF, leading to excessive deposition of extracellular matrix (ECM) and promoting the progression of fibrosis. Inhibiting the excessive activation and relieving autophagy blockage of myofibroblasts is the key to treat IPF. PI3K/Akt/mTOR pathway plays a key regulatory role in promoting fibroblast activation and autophagy inhibition in lung fibrosis. Duvelisib is a PI3K inhibitor that can simultaneously inhibit the activities of PI3K-δ and PI3K-γ, and is mainly used for the treatment of relapsed/refractory chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma tumour (SLL). In this study, we aimed to examine the effects of Duvelisib on pulmonary fibrosis. We used a mouse model of bleomycin-induced pulmonary fibrosis to evaluate the effects of Duvelisib on pulmonary fibrosis in vivo and further explored the potential pharmacological mechanisms of Duvelisib in lung fibroblasts in vitro. The in vivo experiments showed that Duvelisib significantly alleviated bleomycin-induced collagen deposition and improved pulmonary function. In vitro and in vivo pharmacological experiments showed that Duvelisib dose-dependently suppressed lung fibroblast activation and improved autophagy inhibition by inhibiting the phosphorylation of PI3K, Akt and mTOR. Our results indicate that Duvelisib can alleviate the severity of pulmonary fibrosis and provide potential drugs for the treatment of pulmonary fibrosis. 相似文献
90.