Action of sodium diethyldithiocarbamate (NaDDC) on the HILL activity and chlorophyll fluorescence inAnacystis nidulans IU 625

1992 ◽  
Vol 32 (2) ◽  
pp. 119-128 ◽  
Author(s):  
D. P. Singh ◽  
R. Gothalwa ◽  
P. S. Bisen
Keyword(s):  
Chlorophyll Fluorescence ◽  
Sodium Diethyldithiocarbamate ◽  
Hill Activity ◽  
The Hill

Hill-Activity and P700 Concentration of Chloroplasts Isolated from Radish Seedlings Treated with -Indoleacetic Acid, Kinetin or Gibberellic Acid

1977 ◽  
Vol 32 (9-10) ◽  
pp. 798-802 ◽  
Author(s):  
Claus Buschmann ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Steady State ◽  
Gibberellic Acid ◽  
Photosynthetic Activity ◽  
Indoleacetic Acid ◽  
Photosynthetic Apparatus ◽  
Promotion Effect ◽  
Hill Activity ◽  
The Hill ◽  
Radish Seedlings ◽  
Very High

Abstract The Hill-activity (reduction of DCPIP or methylviologen) and the concentration of P700 were studied in chloroplasts isolated from cotyledons of radish seedlings (R aphanus sativu s L. Saxa Treib), which had been grown with the addition of β-indoleacetic acid (IAA), kinetin, or gibberellic acid.1) The photosynthetic activity of young chloroplasts from 3 day old Raphanus seedlings is very high (c. 180 μmol O2/mol chlorophyll × h) and decreases continuously thereafter with increasing age. The steady state Hill-activity is readied after 8 to 10 days (values of 55 to 50 μmol 02/mg chlorophyll × h).2) Chloroplasts from plants treated with IAA or kinetin not only exhibit higher plastoquinone levels 1,2, but also a higher P700-content and a higher Hill-activity. The promotion effect is more pronounced with kinetin (+ 36 to 40%) than with IAA (+ 12 to 17%).3) Gibberellic acid has a different effect on composition and activity of chloroplasts. In younger seedlings the Hill-activity appears to be somewhat stimulated, without promotion effect on plasto­ quinone 2 or P700 concentration. After 10 days GA3-treated plants show signs of chlorosis combined with a strong decrease in photosynthetic activity.4) The data clearly demonstrate that the composition and activity of the photosynthetic ap­ paratus are under phytohormone control. IAA and even better kinetin promote the light induced formation of pigment systems and electrontransport chains. GA3 seems to block the rebuilding of the photosynthetic apparatus under steady state conditions.

A COMPARATIVE ANALYSIS OF LEAF CHLOROPHYLL FLUORESCENCE, HILL REACTION ACTIVITY AND 14C-ATRAZINE TRACER STUDIES TO EXPLAIN DIFFERENTIAL ATRAZINE SUSCEPTIBILITY IN WILD TURNIP RAPE (Brassica campestris) BIOTYPES

1984 ◽  
Vol 64 (3) ◽  
pp. 707-713 ◽  
Author(s):  
A. ALI ◽  
V. SOUZA MACHADO
Keyword(s):  
Chlorophyll Fluorescence ◽  
Brassica Campestris ◽  
Foliar Application ◽  
Decisive Role ◽  
Hill Reaction ◽  
Turnip Rape ◽  
Leaf Chlorophyll ◽  
Leaf Chlorophyll Fluorescence ◽  
The Hill ◽  
Hill Reaction Activity

Leaf chlorophyll fluorescence in susceptible B. campestris L. plants was greatly enhanced and the Hill reaction activity of isolated chloroplasts was inhibited by 10−4 M atrazine. The herbicide did not produce similar responses in resistant plants. 14C-atrazine was used to determine if, in addition, there were differences in uptake, translocation, and metabolism of the herbicide by the susceptible and resistant biotypes. The 14C-atrazine in nutrient solution was readily taken up by the roots of both biotypes and was rapidly translocated to the shoot. The 14C-atrazine was quickly metabolized and after a 24-h period 56 and 63% of the extractable radioactivity in susceptible and resistant plants, respectively, was present as metabolites, the major one being 2-hydroxyatrazine. Following a foliar application, less than 1% of the applied radioactivity moved into other parts of the plant. These results clearly show that triazine resistance in wild turnip rape is based in the chloroplast and that uptake, translocation, and metabolism of the herbicide play no decisive role in selectivity between the susceptible and resistant biotypes.Key words: Atrazine selectivity, Brassica campestris, chlorophyll fluorescence, Hill reaction, atrazine metabolism.

Die Wirkung von Simazin auf die Bildung der plastidären Prenyllipide in Keimlingen von Hordeum vulgare L./Effect of Simazine on Formation of Chloroplasts Prenyllipids in Seedlings of H ordeum vulgare L.

1979 ◽  
Vol 34 (1-2) ◽  
pp. 110-113 ◽  
Author(s):  
H. K. Kleudgen
Keyword(s):  
Chlorophyll A ◽  
Photosynthetic Activity ◽  
Red Light ◽  
Hill Reaction ◽  
Common Site ◽  
Hordeum Vulgare L ◽  
Hill Activity ◽  
Multiple Process ◽  
The Hill ◽  
Β Carotene

Abstract Barley seedlings were grown for 7, 10 or 13 days under continuous white light (Fluora lamps) on a nutrient solution containing simazine (2-chloro-4,6-bis-(ethylamino)-s-triazine, 10, 100 μᴍ) . Accumulation of chlorophylls and in part of carotenoids was increasingly enhanced depending on age and concentrations applied. The ratio chlorophyll a/b decreased on this line in 10 and 13 day old plants, the ratio xanthophylls/β-carotene and the ratio chlorophyll a/prenylquinones (plasto-quinone-90X. + red. , α-tocopherol, α-tocoquinone) increased. The way how these prenyllipid ratios are changed in 10 and 13 day old plants is characteristic of a shade type adaptation, as it was shown earlier for other herbicides inhibiting photosystem II.In 7 day old plants the ratio chlorophyll a/prenylquinones decreased. Photosynthetic activity (Hill-reaction) was enhanced in the simazine plants. The ratio chlorophyll a/b was higher, the ratio xanthophylls/β-carotene was lower than in the older seedlings.Similar changes of prenyllipid ratios like in 7 day seedlings and a higher Hill activity were also found in plants grown under blue light (sun type adaptation) as compared to red light (shade type adaptation). This points to similar metabolic changes in the chloroplasts which could be related to a common site of regulation, perhaps the endogenuous cytokinins. The Hill activity, increasing with age in the 10 and 13 day plants, indicates that the mode of action of simazine may be a multiple process resulting to a parallel formation of shade type and sun type characteristics.

Cyanoacrylate Inhibitors as Probes for the Nature of the Photosystem II Herbicide Binding Site

1990 ◽  
Vol 45 (5) ◽  
pp. 336-342 ◽  
Author(s):  
John L. Huppatz ◽  
Helen G. McFadden ◽  
Leslie F. McCaffery
Keyword(s):  
Binding Site ◽  
Hydrophobic Effect ◽  
Phenyl Group ◽  
Hill Reaction ◽  
Structure Activity ◽  
Herbicide Binding ◽  
Hill Activity ◽  
Quantitative Structure Activity Relationships ◽  
The Hill ◽  
Different Parts

Three series of phenyl-substituted 2-cyanoacrylates were evaluated using simple quantitative structure activity relationships (QSAR) in an attempt to elucidate the nature of the regions of the binding site occupied by different parts of the molecules. Inhibition of the Hill reaction by substituted 3-phenylamino-2-cyanoacrylates correlated well with the lipophilicity of the substituent. The hydrophobic effect was also dominant when the Hill activity of a series of 3-benzylamino-2-cyanoacrylates was analyzed, although potency was considerably higher in the latter series. Lipophilicity and the electronic nature of the substituents were not major determinants in the Hill inhibitory activity of a series of substituted phcnoxycthyl 2-cyanoacrylic esters. In this case, a significant correlation was found with the molar rcfractivity (MR) of meta substituents, a parameter reflecting substituent size. The results indicate that the phenyl moiety of substituted 3-phenylamino- and 3-bcnzyl- amino-2-cyanoacrylates interacts with an essentially lipophilic binding domain, though it is likely that the two series are oriented differently with the 3-bcnzylamino series able to bind with greater affinity. In the phcnoxycthyl ester series, the substituted phenyl group interacts with a different environment, wherein ortho- and we7tf-substitution is tolerated, dependent on the bulk of the substituent, but /wra-substitution is detrimental to affinity for this region of the site.

Einfluß von Röntgenstrahlen auf HILL-Reaktion und Photosynthesephosphorylierung bei verschiedener Erhaltung isolierter und fragmentierter Chloroplasten

1965 ◽  
Vol 20 (11) ◽  
pp. 1077-1085 ◽  
Author(s):  
E. Perner ◽  
S. von Falck ◽  
G. Jacobi
Keyword(s):  
Oxygen Evolution ◽  
Structural State ◽  
Dose Effect ◽  
Hill Reaction ◽  
X Rays ◽  
Membrane Systems ◽  
Low Salinity ◽  
Hill Activity ◽  
Free Membrane ◽  
The Hill

Isolated chloroplasts and chloroplast-fragments of different structural state characterized by electron microscopy were irradiated with X-rays. The resistance of Hill- activity and phosphorylation coupled with ferricyanide is strongly dependent on the structural state of chloroplasts and thylakoids influenced by isolation media or by treatment with hypotonic media or digitonin. Whole chloroplasts are more resistant than free membrane systems without stroma and envelop. If free membrane systems were suspended in media of low salinity (broken chloroplasts) the rate of oxygen evolution and of phosphorylation decreases with a factor of 3.8 or 3.0 respectively after irradiation. Hill- reaction and phosphorylation are suppressed successively by washing the particles in hypotonic media or by treatment with digitonin. However, the sensitivity of oxygen evolution against X-rays remains constant in the washed particles whereas the rate of ATP-formation further decreases. As demonstrated by dose effect curves low intensities of X-rays activated the Hill- activity for all fractions. The results are discussed in relation to the integrity of chloroplasts and the state of membrane (thylakoids) as carrier for the systems of Hill - reaction and phosphorylation.

scholarly journals Comparative Studies of the Hill Activity of Differentially Centrifuged Chloroplast Fractions

1965 ◽  
Vol 40 (2) ◽  
pp. 243-250 ◽  
Author(s):  
M. J. Becker ◽  
A. M. Shefner ◽  
J. A. Gross
Keyword(s):  
Comparative Studies ◽  
Hill Activity ◽  
The Hill

Pentachlorophenol Inhibits Photosynthetic Electron Flow and Quenches Chlorophyll Fluorescence after Preillumination

1986 ◽  
Vol 41 (4) ◽  
pp. 433-436 ◽  
Author(s):  
Christof Niehrs ◽  
Jan Ahlers
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Electron Flow ◽  
Hill Reaction ◽  
Light Requirement ◽  
Ps Ii ◽  
Photosynthetic Electron Flow ◽  
Fluorescence Quench ◽  
The Common ◽  
The Hill

The pesticide PCP was shown to inhibit the Hill reaction in broken chloroplasts (I50 = 15 μᴍ) and to quench chlorophyll fluorescence. Both effects require preillumination. In contrast to the common “phenol-type” inhibitors, neither inhibition of Hill reaction nor chlorophyll fluorescence quench were affected by pretreatment of chloroplast with trypsin instead of preillumination. An inhibition site differing from the “phenol type” inhibitors is therefore assumed. The results presented indicate that the observed light requirement is due to electron transport through PS II. Measurements of intrinsic tryptophane fluorescence relate the PCP site of binding to a hydro- phobic environment.

Sign in / Sign up

Export Citation Format

Share Document