Studies on Lolium Multiflorum Endosperm in Tissue Culture III. Structural Studies on the Cell Walls

1978 ◽  
Vol 31 (5) ◽  
pp. 573 ◽  
Author(s):  
Robin L Anderson ◽  
BA Stone

Cell wall preparations from ryegrass endosperm cells grown in tissue culture contain polysaccharides composed of glucose, xylose, arabinose and galactose residues. The protein content is very low. The cell wa.ll preparations have been fractionated by successive extraction with water at 40�C, 8 M urea, O�5 M KOH, 4�27 M KOH and 6 M NaOH-O' 81 M H3B03 ? The polysaccharides in the fractions were identified by monosaccharide and methylation analysis, supplemented by the use of a specific fi-glucan hydrolase. The results indicate that the three' main types of polysaccharide present are 1,3: 1,4-fi-glucan, arabinoxylan and/or galacto-arabinoxylan and cellulose.

1985 ◽  
Vol 65 (1) ◽  
pp. 99-105 ◽  
Author(s):  
P. NARASIMHALU ◽  
H. T. KUNELIUS ◽  
K. A. WINTER ◽  
K. B. McRAE

Timothy (Phleum pratense L.) and Italian and Westerwolds ryegrasses (Lolium multiflorum Lam.) were harvested as first-cut wilted silages in 1979 and 1980 and were compared on the basis of composition, intake and digestibility. Timothy silage had more cell wall content and was less digestible than the annual ryegrass silages in both years (P < 0.05). Seeding year timothy was consumed less than Aubade ryegrass in 1979 but the postseeding year timothy silage was equal in intake to 1980 Aubade silage but inferior to Italian ryegrass in digestible protein content and also intake (P < 0.05). Leafier Italian and Promenade ryegrasses were consumed more than the stemmy Aubade ryegrass (P < 0.05). Annual ryegrasses were not significantly different in their composition during 1979 but in 1980, Italian ryegrass contained less cell wall and was more digestible than Aubade ryegrass silage (P < 0.05). Prolonged field wilting in humid weather appeared to be more detrimental to the stemmy Aubade for intake and feed value than to the leafier Promenade and Italian ryegrasses. Seeding year timothy silage had lower feed value than the postseed year timothy silage.Key words: Silage, timothy, annual ryegrass, intake, digestibility, composition


1973 ◽  
Vol 26 (1) ◽  
pp. 135 ◽  
Author(s):  
DJ Mares ◽  
BA Stone

Log phase cells of L. multiflorum endosperm grown in liquid suspension cultures contain large nuclei, mitochondria, protein bodies, compound starch granules, small vacuoles, and multilayered membranous structures. At later stages of growth the cell organelles, protein bodies, and starch granules disappear and in senescent cultures many empty cells are seen.


1980 ◽  
Vol 58 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Carey B. Bottom ◽  
Donald J. Siehr

The alkali-insoluble (R-) fraction from the cell walls of Coprinus macrorhizus var. microsporus is a highly branched glucan, containing α-(1 → 4), β-(1 → 3), and β-(1 → 6) linkages as shown by methylation, partial acid hydrolysis, and enzymic hydrolysis. The α-(1 → 4)-linked segments are joined by occasional β-(1 → 3) links as suggested by the identification of 2-O-α-glucopyranosyl erythritol in the hydrolysate of the reduced, periodate-oxidized glucan. Hydrolysis of the permethylated glucan gave nearly equimolar amounts of 2,4-di- and 2,3-di-O-methyl-D-glucose. Methylation analysis of the residue from enzymic hydrolysis, the "CORE-fraction," indicated the presence of glucose residues in this fraction linked through positions O1, O3, O4, and O6. Hydrolysates of the R-fraction contained mannose, glucosamine, and amino acids in addition to glucose.


2016 ◽  
Vol 14 (4) ◽  
pp. e0808
Author(s):  
Vesna Hadži-Tašković Šukalović ◽  
Mirjana Vuletić ◽  
Ksenija Marković ◽  
Željko Vučinić ◽  
Natalija Kravić

Antioxidant systems of maize root cell walls grown on different nitrogen sources were evaluated. Plants were grown on a medium containing only NO3- or the mixture of NO3-+NH4+, in a 2:1 ratio. Eleven-day old plants, two days after the initiation of lateral roots, were used for the experiments. Cell walls were isolated from lateral roots and primary root segments, 2-7 cm from tip to base, representing zones of intense or decreased growth rates, respectively. Protein content and the activity of enzymes peroxidase, malate dehydrogenase and ascorbate oxidase ionically or covalently bound to the walls, as well as cell wall phenolic content and antioxidant capacity, were determined. Cell walls of plants grown on mixed N possess more developed enzymatic antioxidant systems and lower non-enzymatic antioxidant defenses than cell walls grown on NO3-. Irrespective of N treatment, the activities of all studied enzymes and protein content were higher in cell walls of lateral compared to primary roots. Phenolic content of cell walls isolated from lateral roots was higher in NO3--grown than in mixed N grown plants. No significant differences could be observed in the isozyme patterns of cell wall peroxidases isolated from plants grown on different nutrient solution. Our results indicate that different N treatments modify the antioxidant systems of root cell walls. Treatment with NO3- resulted in an increase of constitutive phenolic content, while the combination of NO3-+NH4+ elevated the redox enzyme activities in root cell walls.


Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).


2008 ◽  
Vol 56 (3) ◽  
pp. 341-348
Author(s):  
P. Pepó ◽  
A. Kovács

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.


1982 ◽  
Vol 47 (5) ◽  
pp. 1530-1536 ◽  
Author(s):  
Ladislav Bilisics ◽  
Štefan Karácsonyi ◽  
Marta Kubačková

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1263
Author(s):  
David Stuart Thompson ◽  
Azharul Islam

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.


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