Plant cell models

Systems for evaluating electrolytes for metal electrowinning have been developed and are being used commercially in zinc production (96). Computerized mathematical models of zinc electrowinning cells have been developed and vaUdated by comparison with experimental data taken from pilot-plant cells (97). 

The production of secondaiy metabohtes has often been characterized using the classical equations of Leudeldng and Piret. However, the complexities of plant cell and tissue cultures have led to revisions to this equation to include fresh cell weight and viability, cell expansion, and culture death phase. Therefore, the production model is written as the following ... 

Kacurakova, M., Capek, P., Sasinkova, V., WeUner, N. Ebringerova, A. (2000). FT-IR study of plant cell wall model compounds pectic polysaccharides and hemicelluloses. Carbohydrate Polymers, Vol. 43,2, (October 2000), pp. (195-203), ISSN 0144-8617... 

Dunlop [18] proposed a model for sub-lytic effects in plant cells, based on the same principles, but including four properties postulated to be of particular importance in these systems, namely calcium ion flux, osmo-regulation, cell-cell contact/aggregation and stress protein expression. Of these factors, osmo-regulation (and its inter-relationship with the cell wall) and aggregation patterns, in particular, distinguish plant cells from mammalian cell systems. 

Fig. 11. Hypothetical model for the oxidative burst in plant cells, in response to mechanical stress. Based on [174] and [172]...

In this work, a suspension culture of Taxus chinensis, which produces a bioactive taxoid, taxuyunnanine C (Tc), was taken as a model plant cell system. Experiments on the timing of jasmonates addition and dose response indicated that day 7 and 100 pM was the optimal elicitation time and concentration for both cell growth and Tc accumulation [8]. ITie Tc accumulation was increased more in the presence of novel hydroxyl-containing jasmonates compared to that with methyl jasmonate (MJA) addition. For example, addition of 100 pM... 

IS A GENERAL MODEL FOR PLANT CELL WALL PECTIC SUBSTANCES FEASIBLE ... 

This study is the first report of the presence of rhamnogalacturonan n in fruit-derived products with the exception of the RG-n from wine [20]. Our RG-II preparations correspond very closely to the described model [1,13], confirming the conservation of its structure among plant cell walls. The complexity of the structure and composition of RG-II with several rare sugars uneasy to identify may be one possible explanation of why this fascinating molecule remained undetected in apple juices for such a long time. 

Such a study has been performed on a model plant system, the Nitella flexilis cell wall [1, 2, 3]. This freshwater alga has giant intemodal cells whose easily isolated cell walls constitute a simplified model of higher plant cell walls it has no lignin and its pectin is not methylesterified. Isolated cell walls are cut in pieces and distributed in different lots over the whole exchange isotherm to reduce variability between experimental points. 

Recent models of the plant cell wall are simplified representations based mainly on what is seen by microscopy but also incorporating information from chemical techniques (1,2). However, electron microscopy is a moisture sensitive... 

Chemiker sind der Zelle auf der Spur, Handelsblatt, August 2000 Plant cells as model for micro-reactor development availability of micro-flow devices German leadership first production applications BASF s motivation spotting for DNA arrays materials for micro reactors Merck production plant smallness for efficiency, but not an end in itself [232],... 

Chemiefabrik in der Grojie eines Chips, Handdsblatt, May 1996 Vision of shoe box-sized micro reactors plant cells as model for micro-reactor development cost, performance, and safety advantages LIGA process numbering-up safety processing of hazardous substances [237]. 

Sichere Chemie in Mikroreaktoren, Frankjurter Allgemeine Zeitung, December 1995 Plant cells as model for micro-reactor development micro-fabrication techniques DuPont s investigations DECHEMA s initiation of micro-reactor platform BASF s investigations general advantages of micro flow [238]. 

Onnerud, H. Zhang, L. Gellerstedt, G. Henriksson, G. Polymerization of monolignols by redox shuttle-mediated enzymatic oxidation a new model in lignin biosynthesis I. Plant Cell 2002, 14, 1953-1962. 

The book is divided into 3 sections. Section I.Cellular Model Systems, includes 3 chapters (Allelopathy and plant cell diagnostics, Cellular models as biosensors and microalgae for determining the effects of allelochemicals). Section II. New Methods of Microscopy has 5 chapters (Microscopic methods to study morpho-cytological events during the seed germination,... 

Fry SC, Miller JG. Toward a working model of the growing plant cell wall. Phenolic cross-linking reactions in the primary cell walls of dicotyledons. American Chemical Society, Washington, DC, 1989. 

Terrashima N, Fukushima K, He LF, Takabe K. Comprehensive model of the lignified plant cell wall, in Forage Cell Wall Structure and Digestibility, ASA-CSSA-SSSA, Madison, WI, Chapter 10, 1993. 

Figure 8.7 Simplified model of nicotiniamine (NA) function in plant cells. Iron is transported across the plasma membrane by the Strategy I or Strategy II uptake systems. Once inside the cell, NA is the default chelator of iron to avoid precipitation and catalysis of radical oxygen species. The iron is then donated to proteins, iron-sulfur clusters and haem, while ferritin and iron precipitation are only present during iron excess. (From Hell and Stephan, 2003. With kind permission of Springer Science and Business Media.)...

Transporters, particularly those carrying nonlipophilic species across biomembranes or model membranes, can be regarded as vectorial catalysts (and are also called carriers, translocators, permeases, pumps, and ports [e.g., symports and antiports]). Many specialized approaches and techniques have been developed to characterize such systems. This is reflected by the fact that there are currently twenty-three volumes in the Methods in Enzymology series (vols. 21,22,52-56,81,88,96-98,125-127,156-157, 171-174, and 191-192) devoted to biomembranes and their constituent proteins. Chapters in each of these volumes will be of interest to those investigating transport kinetics. Other volumes are devoted to ion channels (207), membrane fusion techniques (220 and 221), lipids (14, 35, 71, and 72), plant cell membranes (148), and a volume on the reconstitution of intracellular transport (219). See Ion Pumps... 

Toward a Working Model of the Growing Plant Cell... 

FRY MILLER Working Model of Growing Plant Cell Wall... 

---