EFFECT OF DICLOFOP METHYL AND 2,4-D ALONE AND IN COMBINATION ON LEAF CELL MEMBRANE PERMEABILITY OF WILD OATS AND BARLEY

1980 ◽  
Vol 60 (2) ◽  
pp. 773-775 ◽  
Author(s):  
NORA F. O’LEARY ◽  
J. T. O’DONOVAN ◽  
G. N. PRENDEVILLE

Diclofop methyl (2-[4-(2,4-dichlorophenoxy)Phenoxy]) propanoic acid increased leaf cell membrane permeability of wild oats at 48 h and barley at 96 h after treatment while 2,4-D did not affect leaf cell membrane permeability in either species. A combination of both herbicides had a similar effect on leaf cell membrane permeability of wild oats as diclofop methyl alone. In barley, the combination increased leaf cell membrane permeability at 24 h after treatment compared to 96 h with diclofop methyl alone.

1979 ◽  
Vol 59 (1) ◽  
pp. 275-277 ◽  
Author(s):  
JACINTA CROWLEY ◽  
G. N. PRENDEVILLE

Leakage of electrolytes from leaf discs of treated wild oats, barley and wheat plants was the criterion used to compare the effect of dichlofop methyl 2-{4-(2, 4-dichlorophenoxy) phenoxy} propionate on leaf-cell membrane permeability in these species. Leakage of electrolytes from wild oats and barley occurred within 12 h and increased up to 96 h following foliar application of the chemical at the rate of 0.112 kg/ha and 0.56 kg/ha, while in wheat it occurred only at the highest rate and after an interval of 48 h. Increases in leaf-cell membrane permeability occurred in each of the three species before the appearance of visible injury such as discoloration or necrotic areas in leaf tips.


1980 ◽  
Vol 60 (2) ◽  
pp. 613-620 ◽  
Author(s):  
JACINTA CROWLEY ◽  
G. N. PRENDEVILLE

Leakage of electrolytes from leaf discs of treated Phaseolus vulgaris L. plants was used to study the effects of several herbicides of different modes of action on leaf-cell membrane permeability. Linuron (N-(3,4-dichlorophenyl)-N-methoxy-N-methylurea), prometryne (4,6-bisisopropylamino-2-methylthio-1,3,5-triazine), bromacil (5,bromo-6-methyl-3-(1-methyl-n-propyl) uracil), sodium azide and dalapon (2,2-dichloropropionic acid) increased leaf-cell permeability at 24 h after treatment and this occurred without appearance of leaf necrosis. Glyphosate (N-(phosphonomethyl) glycine) increased leaf-cell permeability at 96 h and this was always associated with visible injury, including wilting. Paraquat (1,1-dimethyl-4,4-bipyridylium) at 10−5M increased leaf-cell permeability 48 h after treatment, without apparent leaf damage, but at higher concentrations, increased permeability was always associated with visible effects. Chlorpropham (isopropyl N-(d)3-chlorophenyl) carbamate), picloram (4-amino-3,5,6-trichloropicolinic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) did not alter cell permeability even though epinastic symptoms in leaves became evident 24 h after treatment with picloram and 2,4-D.


Weed Science ◽  
1989 ◽  
Vol 37 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Kiet M. Thai ◽  
Sakti Jana ◽  
Larry C. Fowke

Effects of difenzoquat on wild oats grown under controlled environmental conditions were studied. Seedling height and fresh weight were significantly reduced 5 days after postemergence treatment. Dose-dependent increase in cell membrane permeability was detected after a 12-h exposure to the herbicide. Scanning electron micrographs showed normal leaf hairs and cuticular wax but swollen guard cells 10 days after treatment. Ultrastructural changes occurred before the visible symptoms. The primary effect of difenzoquat appears to be the disruption of the tonoplast and plasmalemma. The tonoplast showed greater damage than the plasmalemma. Secondary effects included damage to mitochondria and chloroplasts. Mitochondria were swollen and often ruptured, but the effect did not increase with the duration of exposure. Chloroplasts became spherical in shape, and their contents were also affected. The changes included: accumulation and then disappearance of starch granules, swelling of frets, fusion of granal thylakoids, detachment and then rupture of the outer membrane of the envelope, and clumping of ribosomes. By contrast, natural senescence caused greater injury of the plasmalemma than the tonoplast, a marked increase in size of plastoglobuli, and loss of starch grains without early accumulation.


Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Jon R. Johnson ◽  
Herbert J. Hopen

Sethoxydim {2-[1-(ethoxyimino)-butyl]-5-[2-ethylthio)propyl]-3-hydroxy-2-cyclohexene-1-one}, KK 80 {ethyl-4-[4-[4-(trifluoromethyl)phenoxy] phenoxy]-2-pentenoate}, and RO-13-8895 {acetone-0-2-[D-2-[δ,δ,δ-trifluoro-p-tolyl)-oxy] phenoxy] propionyl] oxime} did not injure plants visibly or reduce the yield of tomatoes (Lycopersicon esculentumL.). Diclofop LC [2,4-(2,4-dichlorophenoxy)phenoxy] propanoic acid] and diclofop HC in combination with oil or surfactant reduced tomato yield because tomatoes retained more of these spray solutions. No herbicide treatments injured onions (Allium cepaL.). All compounds controlled most grass weeds. Tomato plants grown at 29/18 C were injured more by some diclofop treatments than plants grown at 18/7 C. Cell membrane permeability of tomato plants treated with diclofop alone or in combination with adjuvants increased as visual injury symptoms became more severe.


Author(s):  
M. Ashraf ◽  
L. Landa ◽  
L. Nimmo ◽  
C. M. Bloor

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.


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