Chlorophyll a/b Ratios and Photosystem Activity of Mesophyll and Bundle Sheath Fractions From Sodium-Deficient C4 Plants

1989 ◽  
Vol 16 (6) ◽  
pp. 449 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Photosystem Ii ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Bundle Sheath ◽  
C4 Plants ◽  
Amaranthus Tricolor ◽  
Chloris Gayana ◽  
Photosystem Ii Activity

Significantly lower chlorophyll a/b ratios were observed in mesophyll thylakoids extracted from sodium-deficient than normal C4 plants of Amaranthus tricolor, Chloris gayana and Kochia childsii. The chlorophyll a/b ratio of bundle sheath thylakoids was not generally as significantly affected by sodium nutrition as the mesophyll thylakoids. The lower chlorophyll a/b ratio in mesophyll thylakoids of sodium-deficient plants was associated with a lower photosystem II activity. The effect of sodium nutrition on photosystem I activity in the mesophyll thylakoids was dependent upon the species. Although no effect of sodium nutrition on photosystem I was observed in mesophyll thylakoids of K. childsii, photosystem I activity was greater in sodium-deficient than normal plants in A. tricolor. The photosystem II and I activities of the bundle sheath thylakoids were not affected by sodium nutrition in either K. childsii or A. tricolor.

Characterisation of Leaf Fluorescence of Sodium-Deficient C4 Plants: Kinetics of Emissions From Whole Leaves and Fluorescence Properties of Isolated Thylakoids

1989 ◽  
Vol 16 (6) ◽  
pp. 459 ◽  
Author(s):  
CPL Grof ◽  
DBC Richards ◽  
M Johnston ◽  
PF Brownell
Keyword(s):  
Light Harvesting ◽  
Polynomial Function ◽  
Bundle Sheath ◽  
C4 Plants ◽  
Degree Polynomial ◽  
Amaranthus Tricolor ◽  
Fluorescence Kinetics ◽  
C4 Species ◽  
Chloris Gayana ◽  
Kinetics Of

Examination of whole-leaf fluorescence kinetics by means of a second-degree polynomial function showed a decrease in the rate of the rise from Fd to Fp in sodium-deficient compared with normal leaves of the C4 species Kochia childsii and Amaranthus tricolor. This suggests a decreased efficiency in light harvesting and/or utilisation in sodium-deficient plants. Fluorescence ratios (Fv/Fo) of separated mesophyll and bundle sheath thylakoids were both lower from leaves of sodium-deficient compared with normal plants of K. childsii, Chloris gayana, A. edulis and A. tricolor.

scholarly journals Effect of Sodium Nutrition on Chlorophyll a/b Ratios in C4 Plants

1984 ◽  
Vol 11 (4) ◽  
pp. 325 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Chlorophyll A ◽  
Early Stage ◽  
Chlorophyll Concentration ◽  
C4 Plants ◽  
Growth Responses ◽  
Amaranthus Tricolor ◽  
Sodium Deficiency ◽  
Group I ◽  
Chloris Gayana

Methods for the determination of chlorophyll were compared in Amaranthus tricolor, Kochia childsii and Chloris gayana. From sequential extraction data, 96% ethanol appeared to be more efficient than 80% acetone in extracting chlorophyll from these plants. The chlorophyll a/b ratio was significantly lower in sodium-deficient compared to normal C4 plants. Of the group I elements, only sodium, irrespective of the salt supplied to deficient cultures, restored the chlorophyll a/b ratios to the value observed in normal plants. The concentration of sodium required to increase the chlorophyll a/b ratio in leaves of sodium-deficient plants was similar to that required to bring about the growth responses. The increase of the chlorophyll a/b ratio occurred at an early stage during recovery from sodium deficiency preceding the increase in chlorophyll concentration and the growth response. It is therefore likely that the low chlorophyll a/b ratio may be intrinsically associated with the condition of sodium deficiency.

Osmotic stress at membrane level and photosystem II activity in two C4 plants after growth in elevated CO2 and temperature

2019 ◽  
Vol 174 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Leandra Bordignon ◽  
Ana P. Faria ◽  
Marcel G. C. França ◽  
Geraldo W. Fernandes
Keyword(s):  
Photosystem Ii ◽  
Osmotic Stress ◽  
Elevated Co2 ◽  
C4 Plants ◽  
Photosystem Ii Activity ◽  
Elevated Co2 And Temperature ◽  
Membrane Level

The Effect of Deoxycholate-Treatment to the Photoreactions of the Active Pigments in Photosynthesis

1976 ◽  
Vol 31 (1-2) ◽  
pp. 64-67 ◽  
Author(s):  
Günter Döring
Keyword(s):  
Photosystem Ii ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Electron Flow ◽  
Heavy Fraction ◽  
Sodium Ascorbate ◽  
Linear Electron ◽  
System P ◽  
Heat Treated ◽  
Donor System

Abstract In the heavy fraction of deoxycholate-treated spinach chloroplasts the chlorophyll an activity is high and the chlorophyll aI activity is low when no artificial electron donor is added. The addition of the photosystem I donor system N-methyl-phenazonium sulphate plus sodium ascorbate (PMS + Asc) leads to a complete reactivation of the chlorophyll aI reaction. The addition of the photo­system II donor system p-benzohydroquinone plus sodium ascorbate (HQ + Asc) leads to an inhibition of the chlorophyll aII activity. From these results we conclude: 1. Besides an interruption of the linear electron flow between the two photosystems deoxycholate-treatment leads to a block of the electron flow from water to photosystem II. 2. In deoxycholate-treated chloroplasts the linear electron flow in photosystem II just like in Triswashed, heat-treated or aged chloroplasts, is replaced by a cyclic one.

Modulation of the Cytochrome b6/f Complex and Photosystem I Under Growth-Limiting Light in Amaranthus hypochondriacus, an NAD-ME C4 Plant

1996 ◽  
Vol 23 (3) ◽  
pp. 305 ◽  
Author(s):  
MV Sailaja ◽  
VSR Das
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Thylakoid Membranes ◽  
Bundle Sheath ◽  
C4 Plant ◽  
Cytochrome B6 ◽  
Amaranthus Hypochondriacus ◽  
Energy Consuming ◽  
Electron Transport Rates

Highly characteristic responses of thylakoid membranes were observed in function and composition when fully developed plants of Amaranthus hypochondriacus L. grown under light sufficient (2000 μmol m-2 s-1) conditions were transferred to light limited conditions (650 μmol m-2 s-1 and 200 μmol m-2 s-1). The whole-chain, photosystem I and photosystem II electron transport rates were depressed in both bundle sheath and mesophyll thylakoids with remarkable differences between them in variation of rates under limiting light. The reduction in PSI electron transport in the mesophyll could be attributed to reduced PSI centres, while in the bundle sheath, a modulation of cytochrome b6/f complex regulated the rates of PSI electron transport. The requirement for an unaltered number of PSI centres under limiting light in the bundle sheath is ascribed to operation of an energy-consuming C4 pump.

Exogenous electricity flowing through cyanobacterial photosystem I drives CO2 valorization with high energy efficiency

2021 ◽  
Vol 14 (10) ◽  
pp. 5480-5490
Author(s):  
Zhaodong Li ◽  
Chao Wu ◽  
Xiang Gao ◽  
Bennett Addison ◽  
Shrameeta Shinde ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Energy Efficiency ◽  
Photosystem Ii ◽  
Photosystem I ◽  
High Energy ◽  
High Energy Efficiency ◽  
Photosystem Ii Activity ◽  
Co2 Valorization

An integrated photoelectrochemical architecture, with cyanobacteria lacking photosystem II activity, uses photons and exogenous electrons to convert carbon dioxide into carbon fuel products.

scholarly journals A cDNA clone encoding a photosystem I protein with homology to photosystem II chlorophyll a/b-binding polypeptides.

1987 ◽  
Vol 84 (24) ◽  
pp. 8844-8848 ◽  
Author(s):  
N. E. Hoffman ◽  
E. Pichersky ◽  
V. S. Malik ◽  
C. Castresana ◽  
K. Ko ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Cdna Clone
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