The anther cuticle of Zea mays

1986 ◽  
Vol 64 (9) ◽  
pp. 2088-2097 ◽  
Author(s):  
P. C. Cheng ◽  
R. I. Greyson ◽  
D. B. Walden

The cuticular membrane of the anther of Zea mays is ridged or rugose over most of its surface. The ridges arise during anther development and are confined to the cuticular membrane itself with no coincident folding of the cell wall, although some fibrous wall-like material becomes incorporated within the ridges. The height of a ridge, on mature anthers, is about 0.5 μm and although ridges are aligned, for the most part, in the long axis of the organ, ridges are continuous across cell boundaries in all directions. From transmission electron microscope views we conclude that the cuticle is homogeneous with a thickness of approximately 100 nm. The cuticular layer can be removed from the underlying wall by ZnCl2–HCl hydrolysis. Older anthers yield intact cuticles with persistent ridges. The ridges are not retained by cuticles from young anthers. Chloroform or hexane extraction removes about 30% of the dry weight from isolated cuticles. Characterization of the extract by gas–liquid chromatography – mass spectrometry reveals it is mainly composed of a mixture of odd- and even-numbered straight-chain, saturated hydrocarbons (C25 to C34).

1974 ◽  
Vol 1 (2) ◽  
pp. 183 ◽  
Author(s):  
KF Faull ◽  
BG Coombe ◽  
LG Paleg

Two gibberellins, one GA1-like, the other GA3-like, were identified in the extracts of roots and tops of 8-,11- and 15-day-old barley seedlings by paper chromatography, paper electrophoresis, thin-layer chromatography, gas-liquid chromatography and bioassay procedures, followed by combined gas chromatography-mass spectrometry. The amounts of gibberellins in the seedlings ranged from 7 to 11 ng per plant. The concentrations of gibberellins in the seedlings were 32-320 ng/g dry weight and 5-28 ng/g fresh weight; concentrations in the roots were higher than those in the shoots.


1971 ◽  
Vol 54 (4) ◽  
pp. 801-807
Author(s):  
David L Stalling ◽  
James N Huckins

Abstract The isomer composition of the Aroclor 1200 series was characterized by GLC-MS, using temperature programming and SE-30 support-coated, open-tubular capillary columns. A method is described for the preparation and purification of 36Cl-labeled Aroclors 1248 and 1254. Neutron irradiation of the commercial material was used to prepare the 36Cl-labeled material. Purification of the irradiated product was accomplished by silicic acid column chromatography. Yields of the purified product were between 63 and 99%, with no detectable alteration of the isomer composition; 10% of the 36C1 produced was associated with the unchanged PCB isomers and the remaining radioactivity was contained in polychlorinated terphenyls. The terphenyls were produced by irradiation polymerization, and they were easily separated from the PCB components. Mass spectrometry, utilizing either temperature programmed GLC or direct probe sample introduction, was used to characterize the irradiation products. The radioactive materials are being utilized in experiments to determine uptake and metabolism of PCB by aquatic organisms.


1968 ◽  
Vol 108 (3) ◽  
pp. 401-412 ◽  
Author(s):  
R. P. Longley ◽  
A. H. Rose ◽  
B. A. Knights

1. Protoplasts of Saccharomyces cerevisiae N.C.Y.C. 366 were prepared by incubating washed exponential-phase cells in buffered mannitol (0·8m) containing 10mm-magnesium chloride and snail gut juice (about 8mg. of protein/ml. of reaction mixture). Protoplast membranes were obtained by bursting protoplasts in ice-cold phosphate buffer (pH7·0) containing 10mm-magnesium chloride. 2. Protoplast membranes accounted for 13–20% of the dry weight of the yeast cell. They contained on a weight basis about 39% of lipid, 49% of protein, 6% of sterol (assayed spectrophotometrically) and traces of RNA and carbohydrate (glucan+mannan). 3. The principal fatty acids in membrane lipids were C16:0, C16:1 and C18:1 acids. Whole cells contained a slightly greater proportion of C16:0 and a somewhat smaller proportion of C18:1 acids. Membrane and whole-cell lipids included monoglycerides, diglycerides, triglycerides, sterols, sterol esters, phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol+phosphatidylserine. Phosphorus analyses on phospholipid fractions from membranes and whole cells showed that membranes contained proportionately more phosphatidylethanolamine and phosphatidylinositol+phosphatidylserine than whole cells, which in turn were richer in phosphatidylcholine. Phospholipid fractions from membranes and whole cells had similar fatty acid compositions. 4. Membranes and whole cells contained two major and three minor sterol components. Gas–liquid chromatography, mass spectrometry and u.v. and i.r. spectra indicated that the major components were probably Δ5,7,22,24(28)-ergostatetraen-3β-ol and zymosterol. The minor sterol components in whole cells were probably episterol (or fecosterol), ergosterol and a C29 di-unsaturated sterol. 5. Defatted whole cells contained slightly more glutamate and ornithine and slightly less leucine and isoleucine than membranes. Otherwise, no major differences were detected in the amino acid compositions of defatted whole cells and membranes.


2018 ◽  
Vol 127 (1D) ◽  
pp. 13
Author(s):  
Trần Thị Ái Luyến ◽  
Đỗ Thị Bích Thủy ◽  
Trần Thị Văn Thi ◽  
Phan Thị Thu Huyền

<p><strong>Abstract: </strong>The effects of carbohydrate sources in various concentration (2%, 3%, 4%, 5%, 6%) and fermentation conditions (such as initial cell density, temperature, pH and incubation time) on EPS synthesis of <em>Lactobacillus fermentum </em>MC3 were also studied. The results showed that adding different sugars (including glucose, lactose and sucrose) to culture medium significantly increased the EPS production. In comparison with other concentrations, EPS amounts were maximized in the medium supplemented with 4% (w/v) of sugars. The outcome was the highest for glucose, which was 178.207 mg/L, the obtained figures for lactose and for sucrose were 148.614 mg/L and 152.272 mg/L respectively. The results indicated that EPS production by <em>L. fermentum </em>MC3 reached the maximum values in the medium supplemented with 4% (w/v) glucose at 40<sup>0</sup>C, pH 6.0, initial cell density of 10<sup>6</sup>CFU/ml for 48 h cultivation with amount of 200.728 mg/L. By methylation analysis and gas–liquid chromatography–mass spectrometry (GLC–MS), the exopolysaccharide was found to be composed of D-mannose: D-glucose: D-galactose in a molar ratio of 1 : 0.74 : 0.09.</p>


HortScience ◽  
1993 ◽  
Vol 28 (6) ◽  
pp. 659-660 ◽  
Author(s):  
R.J. Griesbach

The flavonoids from flowers of transgenic Petunia ×hybrida Vilm. plants containing the Al gene from Zea mays L. were characterized. The A1 gene encodes the enzyme dihydroflavonol reductase and was introduced into a mutant petunia defective for this gene. Control, nontransgenic plants produced flowers that contained ≈ 50 ng anthocyanin/100 mg tissue dry weight. Anthocyanin distribution was 63% cyanidin, 28% delphinidin, and 9% pelargonidin. In contrast, the transgenic plants produced flowers that contained ≈ 500 ng anthocyanin/100 mg tissue dry weight, with 34% as cyanidin, 12% as delphlnidin, and 54% as pelargonidin. The increase in anthocyanin production in the transgenic plants resulted in a corresponding molar decrease in flavonol accumulation.


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