Cyanoacrylate Inhibitors of Photosynthetic Electron Transport in Atrazine Susceptible and Atrazine Resistant Brassica Chloroplasts

1987 ◽  
Vol 42 (6) ◽  
pp. 670-673 ◽  
Author(s):  
John N. Phillips ◽  
John L. Huppatz
Keyword(s):  
Electron Transport ◽  
Inhibitory Activity ◽  
Photosynthetic Electron Transport ◽  
Resistant Mutant ◽  
Herbicidal Activity ◽  
Optical Isomers ◽  
Wild Type ◽  
Specific Receptor ◽  
Receptor Sites ◽  
Alkyl Moiety

Comparison of the p/50 values for a series of cyanoacrylate derivatives in chloroplasts isolated from atrazinc susccptiblc (wild type) and atrazine resistant (mutant) Brassica napus biotvpes reveal that the degree and direction of discrimination can vary from being 200- fold more active against the wild type to 10-fold more active against the mutant. There appears to be a direct correlation between the level of inhibitory activity in thylakoids isolated from “susceptible” chloroplasts and the level of discrimination between “susceptible” and “resistant” chloroplasts - a correlation which can be improved by allowing for variations in molecular hydrophobicity. Studies with optically active ethoxyethyl-3-alkyl-2-cyano-3-α-methylbenzylamino acrylates suggest that there are specific receptor sites present in both “susceptible” and “resistant” chloroplasts for both the a-methylbenzyl chiral centre and the 3-alkyl moiety. There is a direct relationship between photosynthetic electron transport inhibitory activity and herbicidal activity of optical isomers.

Photosynthetic Electron Transport Inhibition by Pyrimidines and Pyridines Substituted with Benzylamino, Methyl and Trifluoromethyl Groups

2001 ◽  
Vol 56 (3-4) ◽  
pp. 203-210
Author(s):  
Shinpei Ohki ◽  
Hideomi Takahashi ◽  
Nobuhiro Kuboyama ◽  
Kazuya Koizumi ◽  
Hitoshi Kohno ◽  
...  
Keyword(s):  
Electron Transport ◽  
Spinacia Oleracea ◽  
Chenopodium Album ◽  
Photosynthetic Electron Transport ◽  
Herbicidal Activity ◽  
Trifluoromethyl Group ◽  
Wild Type ◽  
Ring Nitrogen ◽  
Group 2 ◽  
Trifluoromethyl Groups

AbstractThe decrease of the number of ring nitrogen atoms of 2-benzylamino-4-methyl-6-trifluoro-methyl-1,3,5-triazines on herbicidal activity and inhibition of photosynthetic electron trans­ port (PET) was assayed using thylakoids from Spinacia oleracea or atrazine-resistant Chenopodium album. Three 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazines, nine pyrimidines with a benzylamino-, methyl-and trifluoromethyl-group, 2-benzylamino-6-methyl-4-trifluoromethyl-pyridine and N-benzyl-3-methyl-5-trifluoromethylaniline were synthesized and assayed. 2-(4-Bromobenzylamino)-4-methyl-6-trifluoromethylpyrimidine exhibited the highest PET inhibitory activity against Spinacia oleracea thylakoids of all compounds tested. The 2-benzylaminopyrimidines and 2-methylpyrimidines having a 4-halobenzylamino group exhibited higher PET inhibition than atrazine and 2-trifluoromethylpyrimidines against Spinacia oleracea thylakoids. These PET inhibitory active compounds also exhibited a strong and similar inhibition both against atrazine-resistant Chenopodium album thylakoids as well as against thylakoids from wild-type Chenopodium. The herbicidal activity of 4-(4-bromoben-zylamino)-2-methyl-6-trifluoromethylpyrimidine was equivalent to that of known herbicides like simetryne, simazine or atrazine.

scholarly journals TIP family aquaporins play role in chloroplast osmoregulation and photosynthesis

2020 ◽  
Author(s):  
Azeez Beebo ◽  
Ahmad Zia ◽  
Christopher R. Kinzel ◽  
Andrei Herdean ◽  
Karim Bouhidel ◽  
...  
Keyword(s):  
Electron Transport ◽  
Oxygen Evolution ◽  
Photosynthetic Electron Transport ◽  
Chloroplast Envelope ◽  
Photosynthetic Oxygen Evolution ◽  
Wild Type ◽  
Thylakoid Lumen ◽  
Photosynthetic Oxygen ◽  
Osmotic Treatment ◽  
Envelope Membranes

SUMMARYPhotosynthetic oxygen evolution by photosystem II requires water supply into the chloroplast to reach the thylakoid lumen. A rapid water flow is also required into the chloroplast for optimal oxygen evolution and to overcome osmotic stress. The mechanisms governing water transport in chloroplasts are largely unexplored. Previous proteomics indicated the presence of three aquaporins from the tonoplast intrinsic protein (TIP) family, TIP1;1, TIP1;2 and TIP2;1, in chloroplast membranes of Arabidopsis thaliana. Here we revisited their location and studied their role in chloroplasts. Localization experiments indicated that TIP2;1 resides in the thylakoid, whereas TIP1;2 is present in both thylakoid and envelope membranes. Mutants lacking TIP1;2 and/or TIP2;1 did not display a macroscopic phenotype when grown under standard conditions. The mutant chloroplasts and thylakoids underwent less volume changes than the corresponding wild type preparations upon osmotic treatment and in the light. Significantly reduced rates of photosynthetic electron transport were obtained in the mutant leaves, with implications on the CO2 fixation rates. However, electron transport rates did not significantly differ between mutants and wild type when isolated thylakoids were examined. Less acidification of the thylakoid lumen was measured in mutants thylakoids, resulting in a slower induction of delta pH-dependent photoprotective mechanisms. These results identify TIP1;2 and TIP2;1 as chloroplast proteins and highlight their importance for osmoregulation and optimal photosynthesis. A third aquaporin, TIP1;1, is present in the chloroplast envelope, and may play role in photosynthesis under excessive light conditions, as based on the weak photosynthetic phenotype of its mutant.

Photoautotrophic Cultured Plant Cells: A Novel System to Survey New Photosynthetic Electron Transport Inhibitors

1991 ◽  
Vol 46 (7-8) ◽  
pp. 563-568 ◽  
Author(s):  
Fumihiko Sato ◽  
Yasuyuki Yamada ◽  
Sang Soo Kwak ◽  
Katsunori Ichinose ◽  
Mitsuhiro Kishida ◽  
...  
Keyword(s):  
Electron Transport ◽  
Cultured Cells ◽  
Plant Cells ◽  
Photosynthetic Electron Transport ◽  
Herbicidal Activity ◽  
Marchantia Polymorpha ◽  
Hill Reaction ◽  
Transport Inhibitors ◽  
Comparison Of The Results ◽  
The Hill

Abstract The responses of photoautotrophic (PA) cultured cells of tobacco (Nicotiana tabacum cv. Samsun NN) and liverwort (Marchantia polymorpha L.) to thirty-eight cyclohexanedione derivatives were surveyed. Each derivative was also tested for inhibitory activity on photosynthetic electron transport (PET), using isolated thylakoids, and herbicidal activity, using seed­ lings and mature plants. Comparison of the results from the different assays showed that the responses of PA cells to each com pound correlated more closely with the responses of seed­ lings and mature plants than did the results of the Hill reaction assays. Our findings suggest that PA cultured cells would be a suitable screening material for identifying potential herbicides with PET-inhibiting activity.

Metribuzin-Resistant Mutants of Chlamydomonas reinhardii

1984 ◽  
Vol 39 (5) ◽  
pp. 437-439 ◽  
Author(s):  
N. Pucheu ◽  
W. Oettmeier ◽  
U. Heisterkamp ◽  
K. Masson ◽  
G.F. Wildner
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
Wild Type ◽  
Binding Studies ◽  
Molecular Weight Range ◽  
Chlamydomonas Reinhardii ◽  
Thylakoid Membrane Proteins ◽  
Mutant Strains ◽  
Resistant Mutants

Herbicide resistance in Chlamydomonas reinhardii cells was induced by mutagenesis with 5-fluorodeoxyuridine and ethylmethanesulfonate. Four mutant strains were isolated and analyzed for resistance against DCMU-type or phenolic inhibitors of photosynthetic electron transport. The mutants were different in both the extent and the pattern of their resistance: the R/S value, i.e. the ratio of I50 values of the inhibition of photosynthetic electron transport in isolated resistant and susceptible thylakoids, varied for metribuzin from 10 000 to 36. The mutant MZ-1 was resistant against metribuzin, atrazine and DCMU, whereas the mutant MZ-2 showed resistance mainly against metribuzin and atrazine. The mutant MZ-3 was similar to MZ-1, but showed a lesser extent of resistance against DCMU. The mutant MZ-4 showed resistance against metribuzin, but not against atrazine. These results demonstrate that the resistance against one herbicide of the DCMU-type (metribuzin) must not be accompanied by similar resistance against te other inhibitors. Binding studies with radioactively labeled herbicides, [14C]metribuzin, [14C]atrazine and [3H]DCMU, and isolated thylakoids supported these observations. Phosphorylation of thylakoid membrane proteins was studied with wild-type cells and resistant mutants under in vivo conditions in the light. The 32P-labeled main proteins bands were in the molecular weight range of 10-14 kDa, 26-29 kDa, 32-35 kDa and 46-48 kDa. The pattern and the extent of incorporation of 32P were similar for the mutants and the wild-type cells.

Inhibition of Photosynthetic Electron Transport by Azaphenanthrenes

1974 ◽  
Vol 29 (9-10) ◽  
pp. 545-551 ◽  
Author(s):  
Walter Oettmeier ◽  
Rolf Grewe
Keyword(s):  
Electron Transport ◽  
Mechanism Of Action ◽  
Inhibitory Activity ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Iron Complexes ◽  
Lower Activity ◽  
Photosynthetic Electron Flow ◽  
Isolated Chloroplasts ◽  
Insight Into

Abstract Various mono-and diazaphenanthrenes were prepared and assayed for their activity as inhibi­tors of photosynthetic electron flow in isolated chloroplasts in order to get more insight into the mechanism of action of the well known inhibitor o-phenanthroline = 1,10-diazaphenanthrene. The results show that 1-, 4-and 5-azaphenanthrene are only slightly less active than 1,10-diazaphen-anthrene. In the case of the different diazaphenanthrenes, 1,4-, 1,7-and 5,6-diazaphenanthrene exhibited somewhat lower activity than 1,10-diaphenanthrene, whereas 2,9-and 4,7-diazaphen-anthrene were completely inactive. Substitution at C-atoms of 1,10-diazaphenanthrene leads to an increase in activity in the case of the 4-and 7-position, regardless of electropositive or electro­ negative substituents, whereas substitution at the 2-, 3-, 5-, 6-, 8-and 9-position leads to a de­ creased activity. The ability of 1,10-diazaphenanthrene to form iron complexes seems to be of little relevance to the inhibitory activity on photosynthetic electron transport. This follows also from the fact that other strong iron complexing agens, like 2.2'-bipyridine or 8-hydroxyquinoline, are not inhibitory

Triazine Resistance in Phalaris paradoxa: Physiological and Molecular Analyses

1987 ◽  
Vol 42 (6) ◽  
pp. 779-782
Author(s):  
Mordechay Schönfeld ◽  
Tuvia Yaacoby ◽  
Adi Ben-Yehuda ◽  
Baruch Rubin ◽  
Joseph Hirschberg
Keyword(s):  
Electron Transport ◽  
Dry Weight ◽  
Resistant Mutant ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Single Mutation ◽  
Wild Type ◽  
Triazine Resistance ◽  
Herbicide Resistant ◽  
Isolated Chloroplasts

Triazine resistance in a mutant biotype of Phalaris paradoxa is accompanied by changes in the chlorophyll fluorescence induction curve, and by reduced quantum yield for electron transport, indicating altered photosystem II activity. However, light-saturated rates of electron transport in isolated chloroplasts, rates of CO2 uptake in leaves and dry weight production of the triazine resistant biotype, are equal or superior to those of the wild type. A single mutation in the psbA gene, leading to a serine to glycine shift at position 264 of the thylakoid membrane 32 kDa Qв- protein. was found in the herbicide resistant mutant. The results indicate that triazine resistance is not necessarily linked to inferior photosynthetic and growth performance.

scholarly journals CHLOROPLAST STRUCTURE AND FUNCTION IN ac-20, A MUTANT STRAIN OF CHLAMYDOMONAS REINHARDI

1970 ◽  
Vol 44 (3) ◽  
pp. 540-546 ◽  
Author(s):  
R. P. Levine ◽  
A. Paszewski
Keyword(s):  
Electron Transport ◽  
Mutant Strain ◽  
Electron Transport Chain ◽  
Co2 Fixation ◽  
Photosynthetic Electron Transport ◽  
Structure And Function ◽  
Wild Type ◽  
Carboxylase Activity ◽  
Transport Chain ◽  
And Function

Photosynthetic electron transport is markedly affected in mixotrophic cells of ac-20 because they lack the capacity to form the wild-type level of cytochrome 559, as well as Q, the quencher of fluorescence of photochemical system II. The other components of the electron-transport chain, as well as reactions dependent upon photochemical system I, are unaffected in the mutant strain. These observations are discussed in terms of the previously reported effects of the ac-20 mutation on CO2 fixation and ribulose-1,5-diphosphate carboxylase activity.

Triazine Resistance in Phalaris paradoxa: Physiological and Molecular Analyses

1987 ◽  
Vol 42 (7-8) ◽  
pp. 779-782 ◽  
Author(s):  
Mordechay Schönfeld ◽  
Tuvia Yaacoby ◽  
Adi Ben-Yehuda ◽  
Baruch Rubin ◽  
Joseph Hirschberg
Keyword(s):  
Electron Transport ◽  
Dry Weight ◽  
Resistant Mutant ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Single Mutation ◽  
Wild Type ◽  
Triazine Resistance ◽  
Herbicide Resistant ◽  
Isolated Chloroplasts

Triazine resistance in a mutant biotype of Phalaris paradoxa is accompanied by changes in the chlorophyll fluorescence induction curve, and by reduced quantum yield for electron transport, indicating altered photosystem II activity. However, light-saturated rates of electron transport in isolated chloroplasts, rates of CO2 uptake in leaves and dry weight production of the triazine resistant biotype, are equal or superior to those of the wild type. A single mutation in the psbA gene, leading to a serine to glycine shift at position 264 of the thyiakoid membrane 32 kDa Qв- protein. was found in the herbicide resistant mutant. The results indicate that triazine resistance is not necessarily linked to inferior photosynthetic and growth performance.

Sign in / Sign up

Export Citation Format

Share Document