Vol. 15â1961 - NorthEastern Weed Science Society
Vol. 15â1961 - NorthEastern Weed Science Society Vol. 15â1961 - NorthEastern Weed Science Society
e. conjugates were found and the amount of the 2,4-» being conj ated into one or - more of these materials varied with the species of plants~ e more tolerant grass plants produced so called "unknown 3 H conjugate· in substantial quantity (3). Ano~her comflound found to undergo conjugation was monur •. Like 2,4-D, this material was conjugated to a pe)tide or a low molecular weig t protein. In this instance the C14·1abeled material'\Illas applied to the plant d at varying intervals subsequ~t to this the pJan~ harvested, sectioned and t e radioactivity extract'ed. This radIoactivity was' then fractionated by pape chromatography and an. attempt made to determine the nature of the radioactive ot on pafler (7). Table 1 shows ,the changes in the concentration of various ra ioactive co.ponents of the plant extract. ' Table 1* Distribu~ion of Major Radioactive Compounds in 80% Ethyl Alcohol 'Extract· of Bean Leave 14-labeled (After treatment with 50 "1 of carbonyl-c CMu. i?lants· harvested after varying intervals. ) Harvested, Days after treatment R f 0. 62-0.66, CMUComplex, '%. R f .84-0.87, Free '%. CMU, 1 hour 1 2 4 8 12 0 5 11 13 19, 19 100 93 87 85 80 81 2. Hydrolysis. The hydrol~tic enzymes of plants are fully capabl of hydrolytic cleavage of bonds in herbicides. Hagen et.al. (10) early d nstrated the ability of plant. lipase to hydrolyze the ester of 2,4-D. Recently v rY good evidence has been brought forth to show,that the various esters of 2,4-D re rapidly hydrolyzed in the plant and that the active compound is, therefore, 2,4 D acid. It would be expecte4 similarly, that other ester-type compounds such as he,carbamates might probably undergo hydrolysis in the plant. Such is the case ith EPTCwhich we have recently been abl,e to show does undergo hydrolysis acco ding .cc the foHowing reaction: 0 It' C3H7)2' N .. C .. S C2H5.+ H2()Enzyme$ ~ C3H7)2 Nil +C2 5 SH + CO 2 *From Fang, Freed, et. al., J. /I.g. Food Chem., 1, 400, 1955. -
The com;onents the distribution of the foregoi.Dg reaction may further be metallJlized of S35 of S:J~ EPTC, Fsng and Theisen (6). 9. as is shown by 3. Oxidation. , , Of ~artlcular interest is the ability of plants to metlbolize herbicides via oxidation. By this means the compound may be radically alter ad or completely des· troyed by the plsnts metabolism. In view of the complexity 0 ~ the plants enzyme system it is not surprising to find that they ~08sess the abi ity to oxidize herbicides nor is it startling to find that the carbon dioxid ~ arising from this oxidation is further incorporated into plant constituents. One of the first compounds coming under investigation 'as endothal. This compound is an effective pre-emergence herbicide for the chen>POd cro?s such as sugar beets and spinach. Their tolerance for this compound i s well known and it was thought possible that these plants might possess the abil ty to metabolize the material giving rise at least in part to the' observed tol,eran e. Accordingly experiments were undertaken using C 4. labeled endothal to de ermine precisely the nature of this relationship. Beets were seeded in soil and a pre-emergence ap~licat on of radioendothal made to the soil. The plants after emergence were harvested t intervals and the amount of radioactivity in the plant determined. It was (iscovered that an appreciable amount of radioactivity could be detected in the Jlant. It was not known from the measurement of total radioac1 ivity in the plant whether or not this existed in the form of the parent radioenc othal or whether it represented products 'arising from metabolic attack by either ahe plant ormicroorganisms of the soils. Accordingly attempts were made to fract ionate the radioactiVity by solvent extraction. This was accomplished by taking dried plant tissue and solvent extracting the material, first with ether and then wUh alcohol. It was demonstrated that the nonpolar solvent, diethyl ether was incapable of extracting endothal whereas the alcohol was an efficient solv~nt for this purpose. The follOWing table shows a distribution of radioactivity in t he different fractions. Table 2 % of Total Radioactivity in Tissue CroD Ether Extract Ethanol Extract Residue Beets 6.8 33.5 59.7 Spinach 8.9 29.7 61.4 ~ Table 3 Ion Exchange Chromatography of Alcohol Extracts Before column After column Beets II CPtI/O.5 1111 13.2 14.5 Beets 12 CPM/O.5ml 13.0 11. b of Beets and Spinach Spinach CPM/O.5ml 15.6 14.1 Radioendot hal CPM/O.5ml 53.5 0.9
- Page 1 and 2: THE USE OF VEGETATIVECHARACTERISTIC
- Page 3 and 4: In a few grasses with smooth sheath
- Page 5 and 6: 5. FACTORSINFLUEUCINGTHE PERFORFANC
- Page 7: 7. The introduction of synthetic or
- Page 11 and 12: grains. We early found that the oat
- Page 13 and 14: 13. Atrazine Days following cpm/O.
- Page 15 and 16: 15. not find an abundant production
- Page 17 and 18: Weed Control In Suburbia 1 Howard H
- Page 19 and 20: For establishing new lawns, I would
- Page 21 and 22: Any improvement that you can make i
- Page 23 and 24: PROMISINGNEWCHEMICALSFORWEEDCONTROL
- Page 25 and 26: 25. Promis ins results have also be
- Page 27 and 28: 27. (Lycbnis alba), cinquefoil (Pot
- Page 29 and 30: THE EFFECTS OF ADDED PENETRANT AIDS
- Page 31 and 32: ... Surfactant Produced bz: . 31
- Page 33 and 34: 33. 33. of scintillation solution,
- Page 35 and 36: Table 3. The Net Counts Per Minute
- Page 37 and 38: The comparisons for lower leaves, s
- Page 39 and 40: 39. SUMMARY Tests using 2-C 14-1abe
- Page 41 and 42: 41. RECENTDEVELOPMENTS IN THEUSE OF
- Page 43 and 44: second application be made not late
- Page 45 and 46: 45. Combinations of vegadex-Randox
- Page 47 and 48: 11/ Persistence of Soil-Incorporate
- Page 49 and 50: Plot size varied from 9 sq. ft. to
- Page 51 and 52: Lower rates of R-1856 were tested o
- Page 53 and 54: greenhouse tests are listed below.
- Page 55 and 56: PROGRESSREPORTON LAY-BYUEEDCONTROLI
- Page 57 and 58: 57. Table 1. Effect of sodium silic
e.<br />
conjugates were found and the amount of the 2,4-» being conj ated into one or -<br />
more of these materials varied with the species of plants~ e more tolerant<br />
grass plants produced so called "unknown 3 H conjugate· in substantial quantity (3).<br />
Ano~her comflound found to undergo conjugation was monur •. Like 2,4-D, this<br />
material was conjugated to a pe)tide or a low molecular weig t protein. In this<br />
instance the C14·1abeled material'\Illas applied to the plant d at varying intervals<br />
subsequ~t to this the pJan~ harvested, sectioned and t e radioactivity<br />
extract'ed. This radIoactivity was' then fractionated by pape chromatography and<br />
an. attempt made to determine the nature of the radioactive ot on pafler (7).<br />
Table 1 shows ,the changes in the concentration of various ra ioactive co.ponents<br />
of the plant extract. '<br />
Table 1*<br />
Distribu~ion of Major Radioactive Compounds<br />
in 80% Ethyl Alcohol 'Extract· of Bean Leave<br />
14-labeled<br />
(After treatment with 50 "1 of carbonyl-c CMu. i?lants·<br />
harvested after varying intervals. )<br />
Harvested,<br />
Days after treatment<br />
R f 0. 62-0.66, CMUComplex,<br />
'%.<br />
R f .84-0.87, Free<br />
'%.<br />
CMU,<br />
1 hour<br />
1<br />
2<br />
4<br />
8<br />
12<br />
0<br />
5<br />
11<br />
13<br />
19,<br />
19<br />
100<br />
93<br />
87<br />
85<br />
80<br />
81<br />
2. Hydrolysis.<br />
The hydrol~tic enzymes of plants are fully capabl of hydrolytic<br />
cleavage of bonds in herbicides. Hagen et.al. (10) early d nstrated the ability<br />
of plant. lipase to hydrolyze the ester of 2,4-D. Recently v rY good evidence has<br />
been brought forth to show,that the various esters of 2,4-D re rapidly hydrolyzed<br />
in the plant and that the active compound is, therefore, 2,4 D acid. It would be<br />
expecte4 similarly, that other ester-type compounds such as he,carbamates might<br />
probably undergo hydrolysis in the plant. Such is the case ith EPTCwhich we<br />
have recently been abl,e to show does undergo hydrolysis acco ding .cc the foHowing<br />
reaction: 0<br />
It'<br />
C3H7)2' N .. C .. S C2H5.+ H2()Enzyme$ ~ C3H7)2 Nil +C2 5 SH + CO 2<br />
*From Fang, Freed, et. al., J. /I.g. Food Chem., 1, 400, 1955.<br />
-
Change language