scholarly journals Effect of Oxygen on the Contribution of Respiration to the CO2 Compensation Point in Wheat and Bean Leaves

1986 ◽  
Vol 81 (2) ◽  
pp. 379-382 ◽  
Author(s):  
Joaquim Azcon-Bieto
Keyword(s):  
Compensation Point ◽  
Co2 Compensation Point ◽  
Effect Of Oxygen ◽  
Bean Leaves

The influence of red and blue light on the rate of photosynthesis and the CO2 compensation point at various oxygen concentrations

1970 ◽  
Vol 48 (6) ◽  
pp. 1251-1257 ◽  
Author(s):  
N. P. Voskresenskaya ◽  
G. S. Grishina ◽  
S. N. Chmora ◽  
N. M. Poyarkova
Keyword(s):  
Nicotiana Tabacum ◽  
Blue Light ◽  
Photosynthetic Rate ◽  
Prolonged Exposure ◽  
Red Light ◽  
Compensation Point ◽  
Gas Analyzer ◽  
Co2 Compensation Point ◽  
Rate Of Photosynthesis ◽  
Light Inhibition

Apparent photosynthesis of attached leaves of Phaseolus vulgaris, Vicia faba, Pisum sativum, and Nicotiana tabacum at various intensities of blue and red light was measured by infrared CO2 gas analyzer in a closed system. Simultaneously the CO2 compensation point was measured.It was found that light-limited photosynthetic rate in blue light was equal to or more than that in red light. Inhibition of photosynthesis, which sometimes occurred at light-saturated intensities of blue light, could be avoided by addition of red light, prolonged exposure of the plants to blue light, or by lowering the O2 concentration. Accordingly, the increase of photosynthetic rate due to change of O2 concentration from 21 to 3% O2 is higher in blue light only when photosynthesis is inhibited by blue light at 21% O2. The data on the action of blue and red light on the CO2 compensation point seems to exclude the activation of photorespiration by blue light.The possible effects of blue light on apparent photosynthesis are discussed on the basis of the results presented.

C4 Photosynthesis in Sodium-Deficient Plants

1979 ◽  
Vol 6 (4) ◽  
pp. 431 ◽  
Author(s):  
TS Boag ◽  
PF Brownell
Keyword(s):  
C4 Photosynthesis ◽  
Dicarboxylic Acids ◽  
C4 Plants ◽  
Compensation Point ◽  
Short Term ◽  
Sodium Deficiency ◽  
Co2 Compensation Point ◽  
Δ13c Value ◽  
C4 Pathway ◽  
Chloris Barbata

The C4 plants Kochia childsii Hort. and Chloris barbata Sw. showed symptoms characteristic of sodium deficiency. The δ13C value, CO2 compensation point and percentage of 14C label in C4 dicarboxylic acids in short-term photosynthesis were similar in sodium-deficient and normal plants. This is consistent with the operation of the C4 pathway.

Leaf anatomy, gas exchange and photosynthetic enzyme activity in Flaveria kochiana

2007 ◽  
Vol 34 (2) ◽  
pp. 118 ◽  
Author(s):  
Erika A. Sudderth ◽  
Riyadh M. Muhaidat ◽  
Athena D. McKown ◽  
Ferit Kocacinar ◽  
Rowan F. Sage
Keyword(s):  
Gas Exchange ◽  
Leaf Anatomy ◽  
Carbon Isotope Ratio ◽  
Compensation Point ◽  
Initial Slope ◽  
Kranz Anatomy ◽  
Pyruvate Orthophosphate Dikinase ◽  
Co2 Compensation Point ◽  
C4 Species ◽  
Flaveria Species

Flaveria (Asteraceae) is one of the few genera known to contain both C3 and C4 species, in addition to numerous biochemically-intermediate species. C3-C4 and C4-like intermediate photosynthesis have arisen more than once in different phylogenetic clades of Flaveria. Here, we characterise for the first time the photosynthetic pathway of the recently described species Flaveria kochiana B.L. Turner. We examined leaf anatomy, activity and localisation of key photosynthetic enzymes, and gas exchange characteristics and compared these trait values with those from related C4 and C4-like Flaveria species. F. kochiana has Kranz anatomy that is typical of other C4 Flaveria species. As in the other C4 lineages within the Flaveria genus, the primary decarboxylating enzyme is NADP-malic enzyme. Immunolocalisation of the major C4 cycle enzymes, PEP carboxylase and pyruvate, orthophosphate dikinase, were restricted to the mesophyll, while Rubisco was largely localised to the bundle sheath. Gas exchange analysis demonstrated that F. kochiana operates a fully functional C4 pathway with little sensitivity to ambient oxygen levels. The CO2 compensation point (2.2 µbar) was typical for C4 species, and the O2-response of the CO2 compensation point was the same as the C4 species F. trinervia. Notably, F. vaginata (B.L. Robinson & Greenman), a putative C4-like species that is the nearest relative of F. kochiana, had an identical response of the CO2 compensation point to O2. Furthermore, F. vaginata, exhibited a carbon isotope ratio (–15.4‰) similar to C4 species including F. australasica Hooker, F. trinervia Spreng. C. Mohr and the newly characterised F. kochiana. F. vaginata could be considered a C4 species, but additional studies are necessary to confirm this hypothesis. In addition, our results show that F. kochiana uses an efficient C4 cycle, with the highest initial slope of the A/Ci curve of any C4 Flaveria species.

scholarly journals Uncertainty in measurements of the photorespiratory CO2 compensation point and its impact on models of leaf photosynthesis

2017 ◽  
Vol 132 (3) ◽  
pp. 245-255 ◽  
Author(s):  
Berkley J. Walker ◽  
Douglas J. Orr ◽  
Elizabete Carmo-Silva ◽  
Martin A. J. Parry ◽  
Carl J. Bernacchi ◽  
...  
Keyword(s):  
Compensation Point ◽  
Leaf Photosynthesis ◽  
Co2 Compensation Point

scholarly journals Photorespiration and CO2 compensation point in Najas flexilis 1

1978 ◽  
Vol 23 (4) ◽  
pp. 719-724 ◽  
Author(s):  
R. Anton Hough ◽  
Robert G. Wetzel
Keyword(s):  
Compensation Point ◽  
Co2 Compensation Point ◽  
Najas Flexilis
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