scholarly journals Evolutionary bursts inEuphorbia(Euphorbiaceae) are linked with photosynthetic pathway

Evolution ◽  
2014 ◽  
Vol 68 (12) ◽  
pp. 3485-3504 ◽  
Author(s):  
James W. Horn ◽  
Zhenxiang Xi ◽  
Ricarda Riina ◽  
Jess A. Peirson ◽  
Ya Yang ◽  
...  
Keyword(s):  
Photosynthetic Pathway

Anatomical Characteristics of C4 and C3 Photosynthetic-pathway Poaceae Plants in Hainan

2011 ◽  
Vol 46 (4) ◽  
pp. 456-469 ◽  
Author(s):  
Yang Hubiao ◽  
Li Xiaoxia ◽  
Yu Daogeng ◽  
Liu Guodao ◽  
Luo Lijuan
Keyword(s):  
Photosynthetic Pathway ◽  
Anatomical Characteristics

scholarly journals Photosynthetic Characteristics of Four Wild Dendrobium Species in China

HortScience ◽  
2014 ◽  
Vol 49 (8) ◽  
pp. 1023-1027
Author(s):  
Gang-Yi Wu ◽  
Jun-Ai Hui ◽  
Zai-Hua Wang ◽  
Jie Li ◽  
Qing-Sheng Ye
Keyword(s):  
Glycolate Oxidase ◽  
Photosynthetic Pathway ◽  
Light Saturation ◽  
Saturation Point ◽  
Apparent Quantum Yield ◽  
Bisphosphate Carboxylase ◽  
Photosynthetic Physiology ◽  
Light Saturation Point ◽  
Second Peak ◽  
Dendrobium Densiflorum

Photosynthetic physiology of Dendrobium nobile, Dendrobium pendulum, Dendrobium chrysotoxum, and Dendrobium densiflorum was studied. A bimodal diurnal variation of the net photosynthetic rate (Pn) was observed in the four Dendrobium species with the first peak [5.09 to 6.06 μmol (CO2) per m−2·s−1] ≈1100 hr and the second peak [3.83 to 4.58 μmol (CO2) per m−2·s−1] at 1500 hr. No CO2 fixation was observed at night. For all four Dendrobium species, the light compensation point (LCP) was 5 to 10 μmol·m−2·s−1, light saturation point (LSP) ranged from 800 to 1000 μmol·m−2·s−1, apparent quantum yield (AQY) was 0.02, and CO2 compensation points (CCP) and saturation point (CSP) were 60 to 85 μmol·mol−1 and 800 to 1000 μmol·mol−1, respectively. Carboxylation efficiency (CE) values ranged from 0.011 to 0.020. The optimum temperature for photosynthesis was between 26 and 30 °C. The measurement of Pn seasonal variation indicated that July to August had the higher Pn for Dendrobium species. Additionally, the chlorophyll a/b (Chl a/b) ratios of the leaves were 2.77 to 2.89. Measurement of key enzymes in the photosynthetic pathway indicated relatively high Ribulose-1,5-bisphosphate carboxylase (RuBPCase) and glycolate oxidase (GO) activities but very low phosphoenolpyruvate carboxylase (PEPCase) activities. It suggested that these four Dendrobium species are typical semishade C3 plants.

scholarly journals Ecophysiological traits of grasses: resolving the effects of photosynthetic pathway and phylogeny

2009 ◽  
Author(s):  
Samuel Taylor ◽  
Mark Rees ◽  
Stephen Hulme ◽  
Rob Freckleton ◽  
Brad Ripley ◽  
...  
Keyword(s):  
Photosynthetic Pathway ◽  
Ecophysiological Traits

scholarly journals A cyanobacterial photorespiratory bypass model to enhance photosynthesis by rerouting photorespiratory pathway in C3 plants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ghazal Khurshid ◽  
Anum Zeb Abbassi ◽  
Muhammad Farhan Khalid ◽  
Mahnoor Naseer Gondal ◽  
Tatheer Alam Naqvi ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Inorganic Phosphate ◽  
Elevated Level ◽  
Photosynthetic Efficiency ◽  
C3 Plants ◽  
Simultaneous Increase ◽  
Photosynthetic Pathway ◽  
Bisphosphate Carboxylase ◽  
Toxic Compound ◽  
Overall Efficiency

AbstractPlants employ photosynthesis to produce sugars for supporting their growth. During photosynthesis, an enzyme Ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco) combines its substrate Ribulose 1,5 bisphosphate (RuBP) with CO2 to produce phosphoglycerate (PGA). Alongside, Rubisco also takes up O2 and produce 2-phosphoglycolate (2-PG), a toxic compound broken down into PGA through photorespiration. Photorespiration is not only a resource-demanding process but also results in CO2 loss which affects photosynthetic efficiency in C3 plants. Here, we propose to circumvent photorespiration by adopting the cyanobacterial glycolate decarboxylation pathway into C3 plants. For that, we have integrated the cyanobacterial glycolate decarboxylation pathway into a kinetic model of C3 photosynthetic pathway to evaluate its impact on photosynthesis and photorespiration. Our results show that the cyanobacterial glycolate decarboxylation bypass model exhibits a 10% increase in net photosynthetic rate (A) in comparison with C3 model. Moreover, an increased supply of intercellular CO2 (Ci) from the bypass resulted in a 54.8% increase in PGA while reducing photorespiratory intermediates including glycolate (− 49%) and serine (− 32%). The bypass model, at default conditions, also elucidated a decline in phosphate-based metabolites including RuBP (− 61.3%). The C3 model at elevated level of inorganic phosphate (Pi), exhibited a significant change in RuBP (+ 355%) and PGA (− 98%) which is attributable to the low availability of Ci. Whereas, at elevated Pi, the bypass model exhibited an increase of 73.1% and 33.9% in PGA and RuBP, respectively. Therefore, we deduce a synergistic effect of elevation in CO2 and Pi pool on photosynthesis. We also evaluated the integrative action of CO2, Pi, and Rubisco carboxylation activity (Vcmax) on A and observed that their simultaneous increase raised A by 26%, in the bypass model. Taken together, the study potentiates engineering of cyanobacterial decarboxylation pathway in C3 plants to bypass photorespiration thereby increasing the overall efficiency of photosynthesis.

scholarly journals Comparative genomic analysis of C4 photosynthetic pathway evolution in grasses

2009 ◽  
Vol 10 (6) ◽  
pp. R68 ◽  
Author(s):  
Xiyin Wang ◽  
Udo Gowik ◽  
Haibao Tang ◽  
John E Bowers ◽  
Peter Westhoff ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Photosynthetic Pathway ◽  
Pathway Evolution

Occurrence and distribution of native and introduced C4 grasses in Tasmania

2002 ◽  
Vol 50 (6) ◽  
pp. 667 ◽  
Author(s):  
Mark J. Hovenden ◽  
Dennis I. Morris
Keyword(s):  
Urban Areas ◽  
General Distribution ◽  
Grass Species ◽  
Past Century ◽  
C4 Grasses ◽  
Photosynthetic Pathway ◽  
Limited Distribution ◽  
The Past ◽  
C4 Species ◽  
C4 Grass

Of the 137 species of grass considered native to Tasmania, only eight use the C4 photosynthetic pathway. There are also approximately 137 grass species considered as introduced to Tasmania and 21% of these are C4. In total, there are 41 species from 20 genera of C4 grass recorded from Tasmania. Many of the introduced C4 species have a very limited distribution, however, and are generally confined to urban areas and along roadsides. Overall, Tasmania has fewer C4 grasses than would be expected from climate alone and few of the C4 grass species are widely distributed or abundant. However, the proportion of grasses recorded from Tasmania that use the C4 pathway has been increasing for the past century and is still increasing. General distribution and habitat notes are provided for all C4 grasses known to be native or naturalised in Tasmania.

The distribution and ultrastructure of chloroplasts in leaves differing in photosynthetic carbon metabolism. I. Wheat, Sorghum, and Aristida (Gramineae)

1969 ◽  
Vol 47 (1) ◽  
pp. 15-21 ◽  
Author(s):  
T. Bisalputra ◽  
W. J. S. Downton ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Bundle Sheath ◽  
Vascular Bundles ◽  
Photosynthetic Pathway ◽  
Low Carbon ◽  
Mesophyll Cells ◽  
Cytological Evidence ◽  
Bundle Sheath Cells ◽  
Photosynthetic Carbon Metabolism ◽  
High Carbon Dioxide

The ultrastructure of the chlorenchymatous tissues around the vascular bundles of three different types of grass leaves is described. In the temperate grass leaf, as exemplified by wheat, the inner mestom sheath contains proplastids. Normal chloroplasts are found only within the mesophyll cells. Smaller chloroplasts occur in cells of the ill-defined parenchymatic bundle sheath. This type of leaf has the photosynthetic pathway described by Calvin and a high carbon dioxide compensation value. In the tropical grasses, Sorghum and Aristida, the new photosynthetic pathway proposed by Hatch et al. and low carbon dioxide compensation are correlated with development of the parenchymatic bundle sheath. Cytological evidence indicates that cells of the bundle sheath are much more active than the surrounding mesophyll tissue. The specialized chloroplasts of the bundle sheath cells may be responsible for the physiological and biochemical differences between leaves of tropical and temperate grasses.

Photosynthesis in Phosphoenolpyruvate Carboxykinase-Type C4 Species: Properties of Nad-Malic Enzyme From Urochloa panicoides

1987 ◽  
Vol 14 (5) ◽  
pp. 517 ◽  
Author(s):  
JN Burnell
Keyword(s):  
Malic Enzyme ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Bundle Sheath ◽  
Photosynthetic Pathway ◽  
C4 Plant ◽  
C4 Species ◽  
Absolute Requirement ◽  
Pep Carboxykinase ◽  
Fructose 1,6 Bisphosphate ◽  
Regulatory Properties

NAD-malic enzyme (EC 1.1.1.39) was purified from bundle sheath strands of Urochloa panicoides (a phosphoenolpyruvate carboxykinase-type C4 plant) and its kinetic and regulatory properties were investigated. The native enzyme has a molecular weight of about 470 000 and is an octomer composed of two slightly different monomers which occur in a 1 : 1 ratio. The enzyme has an absolute requirement for Mn2+, is stimulated by CoA, acetyl CoA, fructose 1,6-bisphosphate and SO42- and is inhibited by HCO3, oxaloacetate, 2-oxoglutarate and pyruvate. The enzyme is shown to be localised in the mito- chondria. The purified NAD-malic enzyme is unable to catalyse the carboxylation of pyruvate according to the reverse reaction. These findings are discussed in relation to the C4 photosynthetic pathway and its possible role in PEP carboxykinase-type C4 plants.

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