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81.
Simões-Gurgel Claudia Cordeiro Lívia da Silva de Castro Tatiana Carvalho Callado Cátia Henriques Albarello Norma Mansur Elisabeth 《Plant Cell, Tissue and Organ Culture》2011,106(3):537-545
The effects of different levels of Murashige and Skoog (MS) basal medium, 2,4-dichlorophenoxyacetic acid (2,4-D), and sucrose
on anthocyanin production and biomass accumulation of cell suspension cultures of Cleome rosea were investigated. Cultures were established in liquid MS medium containing 30 g l−1 sucrose and supplemented with 0.90 μM 2,4-D. Proliferating cell suspension cultures achieved the highest growth capacity,
a fourfold increase in biomass accumulation, following subculture at the exponential growth phase, 14–18 days of culture.
Moreover, the presence of 2,4-D was essential for anthocyanin production and biomass accumulation. On the other hand, increasing
levels of sucrose above 30 g l−1 resulted in a drastic reduction in biomass accumulation. Anthocyanin production was highest in cell suspension cultures grown
on half-strength MS medium (1/2 MS), 30 g l−1 sucrose, and 0.45 μM 2,4-D. These cell suspension cultures were mainly composed of small aggregates of spherical cells with
similar morphology observed in anthocyanin-producing and non-producing cultures. Moreover, microscopic analysis of anthocyanin-producing
cultures showed the presence of mixtures of non-pigmented, low-pigmented, and high-pigmented cells. 相似文献
82.
G. Pacheco R. F. Gagliardi J. F. M. Valls E. Mansur 《Plant Cell, Tissue and Organ Culture》2009,99(3):239-249
Wild species of Arachis constitute potential sources of novel genes for groundnut improvement programs and some of them are also considered as new
agricultural usage. The majority of these species occur in regions under intensive human activity and their areas of distribution
are being drastically reduced, thus requiring effective conservation measures. Conservation of Arachis germplasm is usually carried out in seed banks or as live plants. However, seed renewal can be impaired by loss of germinative
potential, and plant multiplication under field conditions can be limited by specific soil and environmental requirements
or by low seed yield. Therefore, complementary in vitro methodologies represent an important tool for ex situ conservation
of Arachis germplasm. In this work, we analyse the state of art of micropropagation and the use of in vitro conservation methodologies
for wild relatives of the groundnut. 相似文献
83.
The objective of this paper is to determine the effect of ivermectin administration on cell mediated (CMI) and humoral immunity (HI) of rabbits. CMI against dinitrochlorobenzene (DNCB) and sheep red blood cells (SRBC) in rabbits was determined by delayed-type hypersensitivity and macrophage engulfment assay (MEA), respectively; whereas, HI to Pasteurella multocida B2 vaccine and SRBC was determined by indirect haemagglutination assay (IHA) and Jerne hemolytic plaque formation assay (JHPFA), respectively. The rabbits were divided into four major groups (A through D) each subdivided into four sub-groups (1 through 4). Rabbits of group A served as vehicle control while those of groups B, C and D were treated with ivermectin at the dose rates of 200 microg/kg, 400 microg/kg and 600 microg/kg b.w., respectively. Cellular immunity was determined in sub-groups 1 and 2 through DNCB and MEA, respectively while HI was determined in sub-groups 3 and 4 through IHA and JHPFA, respectively. The skin sensitivity to DNCB at 24 and 48 h and macrophage engulfment of SRBC were highest (P>0.05) in rabbits administered with 600 microg/kg b.w. The highest geometric mean titers (14.00+/-0.31) and number of plaque forming units (1860+/-0.75) were found in rabbits that received ivermectin at a dose of 600 microg/kg b.w. followed, in order by the groups that received 400 microg/kg, 200 microg/kg b.w. and controls. Leukocyte counts were significantly higher in ivermectin-treated groups (C and D) than group A (vehicle control) and B (ivermectin at the rate of 200 microg/kg). A graded dose immune response suggested an immunopotentiating effect of ivermectin at higher doses. 相似文献
84.
Determination of antioxidant activity and phenolic content of extracts from in vivo plants and in vitro materials of Passiflora alata Curtis 总被引:1,自引:0,他引:1
Danielle Lugato Mariela J. Simão Renata Garcia Elisabeth Mansur Georgia Pacheco 《Plant Cell, Tissue and Organ Culture》2014,118(2):339-346
Passiflora alata Curtis, commonly known as sweet passion fruit, is one of the commercially cultivated species of the genus Passiflora, whose fruits can be consumed in natura due to their sweet taste. It is also used worldwide as an ornamental and in folk medicine. The goal of this work was the evaluation of the antioxidant potential of extracts from in vivo plants, and in vitro-derived materials of P. alata. Leaves from in vivo plants were used for the optimization of parameters that affect the efficiency of extraction of antioxidant compounds (proportions of ethanol:water, maceration period, solvent:plant tissue ratio, and number of extraction stages), by employing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activity and the extract yields were significantly influenced by the proportion of ethanol:water and maceration period. The optimized protocol was applied to obtain the extracts of in vitro-derived materials. Total phenolic content was determined using the Folin–Ciocalteu method. Higher antioxidant activities and phenolic contents were observed in extracts from leaves of in vivo-seed derived and from acclimatized plants when compared to in vitro plants, calluses and suspension cultures. Differences in the reaction kinetics of DPPH scavenging activity were also observed. 相似文献
85.
Pereyra-Irujo GA Velázquez L Lechner L Aguirrezábal LA 《Journal of experimental botany》2008,59(8):2221-2232
Plants under water deficit reduce leaf growth, thereby reducing transpiration rate at the expense of reduced photosynthesis. The objective of this work was to analyse the response of leaf growth to water deficit in several sunflower genotypes in order to identify and quantitatively describe sources of genetic variability for this trait that could be used to develop crop varieties adapted to specific scenarios. The genetic variability of the response of leaf growth to water deficit was assessed among 18 sunflower (Helianthus annuus L.) inbred lines representing a broad range of genetic diversity. Plants were subjected to long-term, constant-level, water-deficit treatments, and the response to water deficit quantified by means of growth models at cell-, leaf-, and plant-scale. Significant variation among lines was found for the response of leaf expansion rate and of leaf growth duration, with an equal contribution of these responses to the variability in the reduction of leaf area. Increased leaf growth duration under water deficit is usually suggested to be caused by changes in the activity of cell-wall enzymes, but the present results suggest that the duration of epidermal cell division plays a key role in this response. Intrinsic genotypic responses of rate and duration at a cellular scale were linked to genotypic differences in whole-plant leaf area profile to water deficit. The results suggest that rate and duration responses are the result of different physiological mechanisms, and therefore capable of being combined to increase the variability in leaf area response to water deficit. 相似文献
86.
Zamorano LS Pina DG Arellano JB Bursakov SA Zhadan AP Calvete JJ Sanz L Nielsen PR Villar E Gavel O Roig MG Watanabe L Polikarpov I Shnyrov VL 《Biochimie》2008,90(11-12):1737-1749
The structural stability of a peroxidase, a dimeric protein from royal palm tree (Roystonea regia) leaves, has been characterized by high-sensitivity differential scanning calorimetry, circular dichroism, steady-state tryptophan fluorescence and analytical ultracentifugation under different solvent conditions. It is shown that the thermal and chemical (using guanidine hydrochloride (Gdn-HCl)) folding/unfolding of royal palm tree peroxidase (RPTP) at pH 7 is a reversible process involving a highly cooperative transition between the folded dimer and unfolded monomers, with a free stabilization energy of about 23 kcal per mol of monomer at 25 degrees C. The structural stability of RPTP is pH-dependent. At pH 3, where ion pairs have disappeared due to protonation, the thermally induced denaturation of RPTP is irreversible and strongly dependent upon the scan rate, suggesting that this process is under kinetic control. Moreover, thermally induced transitions at this pH value are dependent on the protein concentration, allowing it to be concluded that in solution RPTP behaves as dimer, which undergoes thermal denaturation coupled with dissociation. Analysis of the kinetic parameters of RPTP denaturation at pH 3 was accomplished on the basis of the simple kinetic scheme N-->kD, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state, and thermodynamic information was obtained by extrapolation of the kinetic transition parameters to an infinite heating rate. Obtained in this way, the value of RPTP stability at 25 degrees C is ca. 8 kcal per mole of monomer lower than at pH 7. In all probability, this quantity reflects the contribution of ion pair interactions to the structural stability of RPTP. From a comparison of the stability of RPTP with other plant peroxidases it is proposed that one of the main factors responsible for the unusually high stability of RPTP which enhances its potential use for biotechnological purposes, is its dimerization. 相似文献
87.
Renata Garcia Georgia Pacheco Erica Falcão Gabriela Borges Elisabeth Mansur 《Plant Cell, Tissue and Organ Culture》2011,106(1):47-54
Passiflora suberosa is used in popular medicine, improvement programs, and as an ornamental plant. The goal of this study was to establish efficient
protocols for plant regeneration and callus induction from nodal, internodal and leaf segments excised from in vitro-grown
plants. The different morphogenetic responses were modulated by the type and concentration of plant growth regulators, according
to the basal medium and light conditions. Shoot formation occurred through three pathways: (1) development of preexisting
meristems, (2) direct organogenesis, and (3) indirect organogenesis. Development of preexisting meristems was observed from
nodal segments (1 shoot/explant) in response to α-naphthaleneacetic acid (NAA), picloram (PIC), and 2,4-dichlorophenoxyacetic
acid (2,4-D), using two basal media (MS and MSM). Direct organogenesis in this species was obtained for the first time in
this work, through shoot development from internodal segments in the presence of 6-benzyladenine (BA). The highest regeneration
rates were achieved on MSM medium, regardless of the BA concentration. Indirect organogenesis was achieved from all explant
types on media supplemented with BA, used alone or in combination with NAA. The highest regeneration efficiency was obtained
from internodal segments cultured on MSM medium plus 44.4 μM BA. Compact, friable, or mucilaginous non-morphogenic calluses
were induced by thidiazuron, PIC, 2,4-D, and NAA. High-yielding friable calluses obtained on MSM medium supplemented with
28.9 μM PIC are being used for the establishment of suspension cultures and further analysis of the production of bioactive
compounds. 相似文献
88.
M. C. Pestana C. Lacorte V. G. de Freitas D. E. de Oliveira E. Mansur 《In vitro cellular & developmental biology. Plant》1999,35(3):214-216
Summary The effect of culture temperature on the morphogenetic response of Arachis hypogaea was studied. Cotyledons were cultivated on MS medium supplemented with 110 μM 6-benzyladenine. Leaf explants were cultivated in the presence of the same growth regulator at 22 μM. Cultures were incubated at temperatures of 25, 28, and 35±5° C. Both direct organogenesis from cotyledons and development
of organogenic calluses from leaves showed optimal rates at 35±5° C. The highest frequency of elongation of buds into shoots
from leaf-derived calluses occurred in the presence of 5 μM AgNO3. At the best culture temperature, an average of 95% of shoots formed roots on growth-regulator-free MS medium. Plants were
successfully transferred to soil, showing normal phenotypes. 相似文献
89.
Carlos Henrique Schneider Maria Claudia Gross Maria Leandra Terencio Roberto Ferreira Artoni Marcelo Ricardo Vicari Cesar Martins Eliana Feldberg 《Reviews in Fish Biology and Fisheries》2013,23(2):201-214
Cichlids are important in the aquaculture and ornamental fish trade and are considered models for evolutionary biology. However, most studies of cichlids have investigated African species, and the South American cichlids remain poorly characterized. Studies in neotropical regions have focused almost exclusively on classical cytogenetic approaches without investigating physical chromosomal mapping of specific sequences. The aim of the present study is to investigate the genomic organization of species belonging to different tribes of the subfamily Cichlinae (Cichla monoculus, Astronotus ocellatus, Geophagus proximus, Acaronia nassa, Bujurquina peregrinabunda, Hoplarchus psittacus, Hypselecara coryphaenoides, Hypselecara temporalis, Caquetaia spectabilis, Uaru amphiacanthoides, Pterophyllum leopoldi, Pterophyllum scalare, and Symphysodon discus) and reexamine the karyotypic evolutionary patterns proposed for this group. Variations in some cytogenetic markers were observed, although no trends were found in terms of the increase, decrease, or maintenance of the basal diploid chromosome number 2n = 48 in the tribes. Several species were observed to have 18S rDNA genetic duplications, as well as multiple rDNA loci. In most of the taxa analyzed, the 5S rDNA was located in the interstitial region of a pair of homologous chromosomes, although variations from this pattern were observed. Interstitial telomere sites were also observed and appear to be involved in chromosomal rearrangement events and the accumulation of repeat-rich satellite DNA sequences. Our data demonstrated the karyotypic diversity that exists among neotropical cichlids, suggesting that most of this diversity is due to the repetitive sequences present in heterochromatic regions and that repeat sequences have greatly influenced the karyotypic evolution of these fishes. 相似文献
90.
Currently, there are a limited number of treatments for ischemic stroke. Intravenous thrombolytic therapy is the most effective method. However, its efficacy is very low in the case of stroke caused by occlusion of large intracranial arteries. Previous studies of endovascular recanalization techniques in the treatment of stroke, particularly randomized controlled trials (RCTs), such as IMS-3, SYNTHESIS Expansion, and MR RESCUE, have shown negative results. The results of other RCTs (MR CLEAN, ESCAPE, EXTENDIA, SWIFT PRIME, and REVASCAT) published in 2015 demonstrated that, in the case of careful selection of patients with verified occlusion of large intracranial arteries, endovascular recanalization significantly improves stroke outcomes. 相似文献