共查询到20条相似文献,搜索用时 30 毫秒
1.
B D Kohorn 《Current opinion in cell biology》2001,13(5):529-533
Students of metazoan biology have traditionally viewed the extracellular matrix (ECM) as a substrate with which cells interact to participate in developmental pattern formation and define a specific location. In contrast, the plant cell wall has been viewed as a cage that limits and thus directs plant cell morphology, and perhaps for this reason many have shied away from calling the plant cell wall the ECM. The recent discovery of a variety of receptor molecules and their ligands on the surface of plant cells and the intimate role cell walls play in development should direct our thinking toward a more dynamic view of the plant cell wall. A recent example, is the discovery of wall associated kinases (WAKs), which may well signal between the ECM and the cell and are required for cell expansion. 相似文献
2.
Kinetic model for biotransformation of digitoxin in plant cell suspension culture ofDigitalis lanata
Jeong-Woo Choi Young-Kee Kim Hyun-Kyu Park Won Hong Lee Dong-Il Kim 《Biotechnology and Bioprocess Engineering》1999,4(4):281-286
Batch suspension cultures ofDigitalis lanata plant cell were performed to investigate the biotransformation of digitoxin.Digitalis lanata K3OHD plant cells were used to biotransform digitoxin into deacetyllanatoside C. A kinetic model was proposed to describe
cell growth, substrate consumption, depletion of digitoxin, formation and depletion of digoxin and purpureaglycoside A, and
formation of deacetyllanatoside C. The digoxin and purpureaglycoside A are intermediates of deacetyllanatoside C formation
from digitoxin. Interactions between extracellular and intracellular compounds were considered. The proposed model could accurately
predict cell growth, substrate consumption and product synthesis. And it can provide a useful framework for quantitative analysis
of biotransformation in a plant cell culture system. 相似文献
3.
Klaus Grossmann Wilhelm Rademacher Hubert Sauter Johannes Jung 《Journal of Plant Growth Regulation》1984,3(1-3):197-205
A comparison of the efficiency of a broad range of plant growth retardants on cell division growth of 13 cell suspension cultures is presented. The results show that (1) the new plant bioregulator tetcyclacis (NDA) is the compound with the highest activity in inhibiting cell division of all cultures tested, and (2) cell cultures react species-specifically to various compounds. Significant correlations between the results from suspension cultures and intact seedlings of the same plant species demonstrate the usefulness of cell cultures for identifying substances with a growth-regulating potency. Futhermore, the usefulness of cell cultures for establishing structure-activity relationships was shown with structural analogues of chlormequat and mepiquat chloride. 相似文献
4.
Jun Ito Thomas Herter Edward E.K. Baidoo Jeemeng Lao Miguel E. Vega-Sánchez A. Michelle Smith-Moritz Paul D. Adams Jay D. Keasling Björn Usadel Christopher J. Petzold Joshua L. Heazlewood 《Analytical biochemistry》2014
Understanding the intricate metabolic processes involved in plant cell wall biosynthesis is limited by difficulties in performing sensitive quantification of many involved compounds. Hydrophilic interaction liquid chromatography is a useful technique for the analysis of hydrophilic metabolites from complex biological extracts and forms the basis of this method to quantify plant cell wall precursors. A zwitterionic silica-based stationary phase has been used to separate hydrophilic nucleotide sugars involved in cell wall biosynthesis from milligram amounts of leaf tissue. A tandem mass spectrometry operating in selected reaction monitoring mode was used to quantify nucleotide sugars. This method was highly repeatable and quantified 12 nucleotide sugars at low femtomole quantities, with linear responses up to four orders of magnitude to several 100 pmol. The method was also successfully applied to the analysis of purified leaf extracts from two model plant species with variations in their cell wall sugar compositions and indicated significant differences in the levels of 6 out of 12 nucleotide sugars. The plant nucleotide sugar extraction procedure was demonstrated to have good recovery rates with minimal matrix effects. The approach results in a significant improvement in sensitivity when applied to plant samples over currently employed techniques. 相似文献
5.
Klaus Grossmann Wilhelm Rademacher Hubert Sauter Johannes Jung 《Journal of Plant Growth Regulation》1984,3(1-4):197-205
A comparison of the efficiency of a broad range of plant growth retardants on cell division growth of 13 cell suspension cultures is presented. The results show that (1) the new plant bioregulator tetcyclacis (NDA) is the compound with the highest activity in inhibiting cell division of all cultures tested, and (2) cell cultures react species-specifically to various compounds. Significant correlations between the results from suspension cultures and intact seedlings of the same plant species demonstrate the usefulness of cell cultures for identifying substances with a growth-regulating potency. Futhermore, the usefulness of cell cultures for establishing structure-activity relationships was shown with structural analogues of chlormequat and mepiquat chloride. 相似文献
6.
Rapid optimization of electroporation conditions for plant cells,protoplasts, and pollen 总被引:1,自引:0,他引:1
James A. Saunders Chin Ho Lin Bi Huei Hou Jianping Cheng Nombasa Tsengwa Jhy Jhu Lin Camelia R. Smith Maria S. McIntosh Sally Van Wert 《Molecular biotechnology》1995,3(3):181-190
The optimization of electroporation conditions for maximal uptake of DNA during direct gene transfer experiments is critical
to achieve high levels of gene expression in transformed plant cells. Two stains, trypan blue and fluorescein diacetate, have
been applied to optimize electroporation conditions for three plant cell types, using different square wave and exponential
wave electroporation devices. The different cell types included protoplasts from tobacco, a stable mixotrophic suspension
cell culture from soybean with intact cell walls, and germinating pollen from alfalfa and tobacco. Successful electroporation
of each of these cell types was obtained, even in the presence of an intact cell wall when conditions were optimized for the
electroporation pulse. The optimal field strength for each of these cells differs, protoplasts having the lowest optimal pulse
field strength, followed by suspension cells and finally germinating pollen requiring the strongest electroporation pulse.
A rapid procedure is described for optimizing electroporation parameters using different types of cells from different plant
sources. 相似文献
7.
8.
A four-step strategy is presented which allows the establishment of plant cell cultures producing high yields of secondary plant products. The application of suitable methods (radioimmunoassay, fluorescence screening) for the selection of overproducing differentiated plants and cell colonies is stressed. By precursor feeding and hormone application, plant cell cultures can greatly be influenced in their production behavior. A highly sensitive, selective regulatory mechanism for the uptake and storage of alkaloids in Catharanthus vacuoles is demonstrated. Overproducing variant cell strains are so far the most promising tool for the future biotechnological application of the plant cell culture method. 相似文献
9.
The C terminus of brome mosaic virus coat protein controls viral cell-to-cell and long-distance movement 下载免费PDF全文
To investigate the functional domains of the coat protein (CP; 189 amino acids) of Brome mosaic virus, a plant RNA virus, 19 alanine-scanning mutants were constructed and tested for their infectivity in barley and Nicotiana benthamiana. Despite its apparent normal replicative competence and CP production, the C-terminal mutant F184A produced no virions. Furthermore, virion-forming C-terminal mutants P178A and D182A failed to move from cell to cell in both plant species, and mutants D181A and V187A showed host-specific movement. These results indicate that the C-terminal region of CP plays some important roles in virus movement and encapsidation. The specificity of certain mutations for viral movement in two different plant species is evidence for the involvement of host-specific factors. 相似文献
10.
Summary A new model of rotating fibre components (helicoidal model) is proposed to explain the architecture of some plant cell walls. On the basis of tilting observations under the electron microscope, we establish the validity of this model for the cell wall ofChara vulgaris oospores. We suggest that this model explains the architecture seen in a number of published micrographs from a variety of different plant cell walls. Helicoidal architecture is shown to be distinct from the previously established crossed polylamellate architecture. The diagnostic features of helicoidal architecture are given. Morphogenesis of plant cell walls is discussed, with particular reference to self assembly in cholesteric liquid crystals. 相似文献
11.
Lignocellulosic biomass is today considered a promising renewable resource for bioenergy production. A combined chemical and
biological process is currently under consideration for the conversion of polysaccharides from plant cell wall materials,
mainly cellulose and hemicelluloses, to simple sugars that can be fermented to biofuels. Native plant cellulose forms nanometer-scale
microfibrils that are embedded in a polymeric network of hemicelluloses, pectins, and lignins; this explains, in part, the
recalcitrance of biomass to deconstruction. The chemical and structural characteristics of these plant cell wall constituents
remain largely unknown today. Scanning probe microscopy techniques, particularly atomic force microscopy and its application
in characterizing plant cell wall structure, are reviewed here. We also further discuss future developments based on scanning
probe microscopy techniques that combine linear and nonlinear optical techniques to characterize plant cell wall nanometer-scale
structures, specifically apertureless near-field scanning optical microscopy and coherent anti-Stokes Raman scattering microscopy. 相似文献
12.
Discusses probable routes of agrobacterial penetration through the plant integumental tissues, cell wall, and plant cell plasmodesma. Analyzes the contribution of extracellular structures of agrobacteria in penetration through barriers of a plant cell, primary contact (adhesion), and during DNA transfer from bacterial (E. coli, A. tumefaciens) to recipient (bacterial or plant) cells. Discusses the relationship between donor cell adhesion to recipient cell surface and the infectious and conjugation processes. Considers the probable role of piles in conjugative transfer of agrobacterial DNA through membranes of donor and recipient (bacterial and plant) cells. Analyzes the contribution of the plant cell cytoskeleton to T-DNA transfer. Suggests a model of transport of T-DNA-VirD2 complex and VirE2 proteins through independent channels consisting of vir-coded proteins. 相似文献
13.
Analysis of transfer of tumor-inducing plasmids from Agrobacterium tumefaciens to Petunia protoplasts. 总被引:4,自引:1,他引:3 下载免费PDF全文
Petunia protoplasts were infected with the virulent Agrobacterium tumefaciens strain A348 or the avirulent strain A136 (lacking a Ti plasmid). The infection process was stopped at various time intervals up to 24 h after inoculation, and the DNA from the plant cells was isolated. Southern blot analysis indicated that the DNA isolated from infected Petunia cells was not detectably contaminated by bacterial DNA from lysed Agrobacterium cells. Analysis of the DNA from the virulent infections suggested that the transferred DNA (T-DNA) may be transferred to the plant cell rapidly (within 2 to 6 h) after the bacteria bind to the cell wall and that the T-DNA may exist in a rearranged state which is stable over the time period investigated. Dot blot analysis indicated that regions far outside the T-DNA may be transferred to the plant cell. Most of the DNA transferred to the plant cell during the initial hours of infection is rapidly degraded. 相似文献
14.
Girard LS Fabis MJ Bastin M Courtois D Pétiard V Koprowski H 《Biochemical and biophysical research communications》2006,345(2):602-607
A Nicotiana tabacum cv. Xanthi cell culture was initiated from a transgenic plant expressing a human anti-rabies virus monoclonal antibody. Within 3 months, plant cell suspension cultures were established and recombinant protein expression was examined. The antibody was stably produced during culture growth. ELISA, protein G purification, Western blotting, and neutralization assay confirmed that the antibody was fully processed, with association of light and heavy-chains, and that it was able to bind and neutralize rabies virus. Quantification of antibody production in plant cell suspension culture revealed 30 microg/g of cell dry weight for the highest-producing culture (0.5 mg/L), 3 times higher than from the original transgenic plant. The same production level was observed 3 months after cell culture initiation. Plant cell suspension cultures were successfully grown in a new disposable plastic bioreactor, with a growth rate and production level similar to that of cultures in Erlenmeyer flasks. 相似文献
15.
Mechanical Response of Single Plant Cells to Cell Poking: A Numerical Simulation Model 总被引:4,自引:0,他引:4
Rong Wangt Qun-Ying Jiao De-Qiang Wei 《植物学报(英文版)》2006,48(6):700-705
Cell poking is an experimental technique that is widely used to study the mechanical properties of plant cells. A full understanding of the mechanical responses of plant cells to poking force Is helpful for experimental work. The aim of this study was to numerically investigate the stress distribution of the cell wall, cell turgor, and deformation of plant cells in response to applied poking force. Furthermore, the locations damaged during poking were analyzed. The model simulates cell poking, with the cell treated as a spherical, homogeneous, isotropic elastic membrane, filled with incompressible, highly viscous liquid. Equilibrium equations for the contact region and the non-contact regions were determined by using membrane theory. The boundary conditions and continuity conditions for the solution of the problem were found. The forcedeformation curve, turgor pressure and tension of the cell wall under cell poking conditions were obtained. The tension of the cell wall circumference was larger than that of the meridian. In general, maximal stress occurred at the equator around. When cell deformation increased to a certain level, the tension at the poker tip exceeded that of the equator. Breakage of the cell wall may start from the equator or the poker tip, depending on the deformation. A nonlinear model is suitable for estimating turgor, stress, and stiffness, and numerical simulation is a powerful method for determining plant cell mechanical properties. 相似文献
16.
Thomas BR Romero GO Nevins DJ Rodriguez RL 《International journal of biological macromolecules》2000,27(2):139-144
Isozymes of glycosyl hydrolase Family 17 hydrolyze 1,3-beta-glucan polysaccharides found in the cell wall matrix of plants and fungi, enabling these plant enzymes to serve diverse roles in plant defense and plant development. Fourteen genes from Family 17 have been characterized in the genome of rice. A sequence dendrogram analysis divided these genes into four subfamilies. The recombinant GNS1 enzyme from subfamily B had 1,3;1,4-beta-glucanase activity, suggesting a role for this isozyme in plant development. 相似文献
17.
Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000) expressing avrRpt2 is specifically recognized by plant cells expressing RPS2 activity, resulting in localized cell death and plant resistance. Furthermore, transient expression of this bacterial avrRpt2 gene in plant cells results in RPS2-dependent cell death. This indicates that the AvrRpt2 protein is recognized inside RPS2 plant cells and is sufficient for the activation of disease resistance-mediated cell death in planta. We explored the possibility that Pst DC3000 delivers AvrRpt2 protein to plant cells via the hrp (type III) secretion pathway. We now provide direct evidence that mature AvrRpt2 protein is secreted from Pst DC3000 and that secretion is hrp dependent. We also show that AvrRpt2 is N-terminally processed when Arabidopsis thaliana plants are infected with Pst DC3000 expressing avrRpt2. Similar N-terminal processing of AvrRpt2 occurred when avrRpt2 was stably expressed in A. thaliana. No cleavage of AvrRpt2 was detected in bacteria expressing avrRpt2 in culture or in the plant extracellular fluids. The N-terminus of AvrRpt2 was not required for RPS2 recognition in planta. However, this region of AvrRpt2 was essential for Pst DC3000-mediated elicitation of RPS2-dependent cell death in A. thaliana leaves. 相似文献
18.
Quanzi Li Jian Song Shaobing Peng Jack P. Wang Guan‐Zheng Qu Ronald R. Sederoff Vincent L. Chiang 《Plant biotechnology journal》2014,12(9):1174-1192
Lignocelluloses from plant cell walls are attractive resources for sustainable biofuel production. However, conversion of lignocellulose to biofuel is more expensive than other current technologies, due to the costs of chemical pretreatment and enzyme hydrolysis for cell wall deconstruction. Recalcitrance of cell walls to deconstruction has been reduced in many plant species by modifying plant cell walls through biotechnology. These results have been achieved by reducing lignin content and altering its composition and structure. Reduction of recalcitrance has also been achieved by manipulating hemicellulose biosynthesis and by overexpression of bacterial enzymes in plants to disrupt linkages in the lignin–carbohydrate complexes. These modified plants often have improved saccharification yield and higher ethanol production. Cell wall‐degrading (CWD) enzymes from bacteria and fungi have been expressed at high levels in plants to increase the efficiency of saccharification compared with exogenous addition of cellulolytic enzymes. In planta expression of heat‐stable CWD enzymes from bacterial thermophiles has made autohydrolysis possible. Transgenic plants can be engineered to reduce recalcitrance without any yield penalty, indicating that successful cell wall modification can be achieved without impacting cell wall integrity or plant development. A more complete understanding of cell wall formation and structure should greatly improve lignocellulosic feedstocks and reduce the cost of biofuel production. 相似文献
19.
Control of the cell cycle. 总被引:3,自引:0,他引:3
T Jacobs 《Developmental biology》1992,153(1):1-15
Cell division is arguably the most fundamental developmental process for single-celled and multicellular organisms alike. The pathway from one cell division to the next is known as the cell cycle. A conserved biochemical regulatory network controls progress along this pathway in plants, animals, and yeasts. This review is intended to serve as a primer on the current state of the eukaryotic cell cycle regulatory model, an introduction to the special roles of cell division and its control in plant development, and a review of recent progress in applying the universal mitotic control paradigm to higher plant systems. 相似文献
20.
Getting to the root: The role of the Agrobacterium rhizogenes rol genes in the formation of hairy roots 总被引:2,自引:0,他引:2
Agrobacterium tumefaciens and A. rhizogenes are the causative agents of the crown gall and hairy root diseases, respectively. The pathogenicity of both species is caused by an inter-kingdom transfer of DNA from the bacteria to wounded plant cells. This 'transfer-DNA' (T-DNA) contains oncogenes whose expression transforms the plant recipient cell into a rapidly dividing tumour cell. In the case of A. tumefaciens , three of these oncogenes have been shown to encode enzymes catalyzing the biosynthesis of the plant growth hormones auxin and cytokinin. Therefore, the unorganized cell division in the crown gall tumour can be largely explained by an unregulated overproduction of these plant growth regulators. In contrast, the hairy root disease is characterized by a massive growth of adventitious roots at the site of infection. Because of the similarities of the infection processes, and because A. rhizogenes and A. tumefaciens are very closely related, it has been suggested that the most important A. rhizogenes oncogenes, the so called rol genes, are also encoding proteins involved in the regulation of plant hormone metabolism. However, recent data indicate that this is not the case. Thus the rol genes have functions that most likely are different from producing mere alterations of plant hormone concentrations. This review summarizes recent results concerning the expression and function of the rol genes, and presents a model for the role of these genes, especially rolB and rolC , in the A. rhizogenes infection process. 相似文献