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.

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.

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.

Free Amino Acid Concentrations in Leaves of Sodium-Deficient C4 Plants

1986 ◽  
Vol 13 (3) ◽  
pp. 343 ◽  
Author(s):  
CPL Grof ◽  
M Johnston ◽  
PF Brownell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Aminobutyric Acid ◽  
Amaranthus Tricolor ◽  
Mature Leaves ◽  
C4 Species ◽  
Chloris Gayana ◽  
Amino Acid Concentrations

Consistent changes in the free amino acid concentrations in response to sodium nutrition were observed in mature leaves of the C4 species Amaranthus tricolor and Chloris gayana. The amino acids alanine, γ-aminobutyric acid and glycine were present in greater and aspartate and arginine in lower concentrations in mature leaves of sodium-deficient than in normal plants of both species.

The Effect of Sodium Nutrition on the Pool Sizes of Intermediates of the C Photosynthetic Pathway

1988 ◽  
Vol 15 (6) ◽  
pp. 749 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Direct Application ◽  
Photosynthetic Pathway ◽  
Growth Responses ◽  
Amaranthus Tricolor ◽  
Mesophyll Cells ◽  
Sodium Deficiency ◽  
C4 Species ◽  
C3 Species ◽  
Chloris Gayana ◽  
Group 1

Changes in C4 pathway intermediates in response to sodium nutrition, consistent with the hypothesis that there is a limitation in the conversion of pyruvate to phosphoenolpyruvate (PEP) in the mesophyll cells in sodium-deficiency, were observed in the C4 species, Kochia childsii, Chloris gayana, Amaranthus edulis, Amaranthus tricolor and Atriplex spongiosa. In the C3 species Lycopersicon esculentum (tomato), no differences were observed when grown with or without added sodium. Of the group 1 elements, only sodium, irrespective of the salt supplied to deficient cultures, effected these changes in the C4 species. In the light, concentrations of aspartate, PEP and 3-phosphoglycerate (3-PGA) were lower and those of pyruvate and alanine were greater in sodium-deficient than normal plants. In the dark, concentrations of aspartate, pyruvate, alanine, PEP and 3-PGA were similar in sodium-deficient and normal plants. In the C4 species Atriplex spongiosa, the concentration of sodium required to bring about these changes corresponded to that required for growth responses. Rapid increases in the concentrations of malate, PEP and 3-PGA and decreases in pyruvate and alanine were observed following the direct application of sodium to leaves.

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