Long-term effects of several biochemical and physical factors on cellulose biosynthesis in callus and suspension cultures of normal and mutant barley (Hordeum vulgare L.) strains producing less cellulose

1998 ◽  
Vol 41 (3) ◽  
pp. 219-226 ◽  
Author(s):  
Up-Dong Yeo ◽  
Woong-Young Soh ◽  
Naoki Nakagawa ◽  
Naoki Sakurai ◽  
Kazuyoshi Takeda
Keyword(s):  
Hordeum Vulgare ◽  
Suspension Cultures ◽  
Physical Factors ◽  
Cellulose Biosynthesis ◽  
Long Term Effects ◽  
Hordeum Vulgare L

Culture methods and detection of glucanases in suspension cultures of wheat and barley

1968 ◽  
Vol 46 (5) ◽  
pp. 417-421 ◽  
Author(s):  
Oluf L. Gamborg ◽  
D. E. Eveleigh
Keyword(s):  
Hordeum Vulgare ◽  
Culture Media ◽  
Early Period ◽  
Suspension Cultures ◽  
Dichlorophenoxyacetic Acid ◽  
Hordeum Vulgare L ◽  
Culture Methods ◽  
Mineral Salts ◽  
Triticum Vulgare ◽  
2,4 Dichlorophenoxyacetic Acid

Suspension cultures of Triticum monococcum L., Triticum vulgare Vill. var. Thatcher, Hordeum vulgare L. var. Gateway, and Hordeum vulgare L. var. Gateway mutant yv2 have been established. The cultures were derived from root sections of seedlings and cultured in a denned medium consisting of mineral salts, sucrose, B vitamins, and 2,4-dichlorophenoxyacetic acid, with nitrate and ammonia as the sources of nitrogen. In the early period of the cultures the cell aggregates readily, differentiated to form roots, but this characteristic diminished after several generations of subculture. The cells and medium contained a number of glucanases. The presence of a laminaranase (endo-β-(1 → 3)-D-glucan glucanohydrolase (EC 3.2.1.99)) that did not attack lichenan was established. The culture media of the wheat contained an oligosaccharide which on acid hydrolysis yielded galactose, arabinose, and xylose. Hydrolysis of a cell-wall fraction yielded the same sugars in addition to glucose and mannose.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

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