Haloxyfop

Halowax 1099 [39450-05-0] Haloxyfop-methyl Pimephales promelas LC5o(96-h) >2.00 Johnson and Finley, 1980... 

FLUORINECOMPOUNDS, ORGANIC - FLUORINATED AROMATIC COMPOUNDS] (Vol 11) Haloxyfop-methyl [69806-40-2]... 

Eksteen, F.H., A.F.P. Cairns, and P.J. Pieterse (2004). Cross resistance of ryegrass to glyphosate, paraquat and haloxyfop-r methyl ester in the Western Cape. 4th International Weed Science Congress, p. 48, S15MT08P00. 

Haloxyfop phenoxy carboxylic acid, pyridine HCH see Lindane... 

Picoline chlorfluazuron, flazasulfuron, fluazifop, fluazinam, haloxyfop 6 Picoline inabenfide Picric acid chloropicrin... 

Propionic acid benalaxyl, benzoylprop-ethyl, clethodim, clodinafop, clomeprop, cloprop, 2 CPA dalapon, dichlorprop, diclofop, fenoprop, fenoxaprop, flamprop isopropyl, flamprop methyl, fluazifop, furalaxyl, haloxyfop, isoxapyrifop, mecoprop, metalaxyl, naproanilide, napropamide, prohexadione, propanil, pyroquilon, quizalofop ethyl, tralkoxydim Propoxy acetaldehyde pretilachlor n-Propylamine prochloraz, profluralin... 

DB dichlorprop diclofop-methyl fenoprop fenoxaprop-ethyl fluazifop-butyl haloxyfop-methyl MCPA... 

Experiments were conducted to determine how quickly a low concentration (1.4 /zM) of an aryloxyphenoxypropanoate, haloxyfop (2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-propanoic acid) (Fig.l) could affect lipid metabolism. We used leaf discs as experimental material because it would mitigate effects of herbicide uptake and translocation. Maize (Zea mays) leaf discs were prepared as previously described (15) and incubated in C-acetate. At various times, discs were removed and cell constituents were separated into organic and aqueous soluble fractions (16). Within 30 min of application, 1.4 /zM of either the free acid or the methyl ester of haloxyfop inhibited lipid... 

Aryloxyphenoxypropanoates and cyclohexanediones are herbicidal to most monocotyledons but not to dicotyledons. A comparison between a susceptible species, barley (Hordeum vulgare), and a tolerant species, soybean (Glycine max) showed that haloxyfop was effective in reducing lipid biosynthesis in barley but not in soybean leaf discs (Table I). 

Table I. Effect of Haloxyfop on l C-Acetate Incorporation into Lipids in Soybean and Barley Leaf Discs After a 40 Minute Incubation Period...

We decided to focus our attention on de novo fatty acid biosynthesis based upon our observations and those reported in the literature (12). To determine whether fatty acid biosynthesis was inhibited, we determined the effect of the herbicides on incorporation into palmitic (16 0) acid, the first product of fatty acid biosynthesis. Maize leaf discs were incubated for 40 min in 14C -acetate, after which fatty acids were extracted. As shown in Table II, both tralkoxydim and haloxyfop significantly reduced the amount of acetate incorporated into palmitic acid. Thus, these compounds affected a step early in lipid biosynthesis. 

Figure 2. Comparison of control (O), 1.4 /zM haloxyfop methyl ester ( ), or 1.4 /iM haloxyfop free acid (A) on l C-acetate incorporation into lipids in maize leaf discs.

Table II. The Effect of Tralkoxydim and Haloxyfop on C-Acetate Incorporation into Palmitic Acid in Maize Leaf Discs...

The activity of ACCase extracted from maize was inhibited by both tralkoxydim and haloxyfop acid in a concentration dependant manner (Fig. 4). The concentration that inhibited activity by 50% (I50) was about 1 / M for both compounds. These values are similar to those recently reported by others (2.3). The methyl ester of haloxyfop was more than 100 fold less inhibitory than the free acid (Fig. 4), which is consistent with the methyl ester being deesterified in the plant. The data presented in Fig. 2 suggest that the deesterification occurs rapidly in leaf tissue. 

Figure 4. Effect of haloxyfop methyl ester (A), haloxyfop free acid (O), and tralkoxydim ( ) on acetyl CoA carboxylase activity from maize.

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