The relationship between CO2-assimilation rate, Rubisco carbamylation and Rubisco activase content in activase-deficient transgenic tobacco suggests a simple model of activase action

Planta ◽  
1996 ◽  
Vol 198 (4) ◽  
pp. 604-613 ◽  
Author(s):  
Colleen J. Mate ◽  
Susanne von Caemmerer ◽  
John R. Evans ◽  
Graham S. Hudson ◽  
T. John Andrews
Keyword(s):  
Simple Model ◽  
Transgenic Tobacco ◽  
Rubisco Activase ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Co2 Assimilation Rate ◽  
The Relationship

Photosynthesis is strongly reduced by antisense suppression of chloroplastic cytochrome bf complex in transgenic tobacco

1998 ◽  
Vol 25 (4) ◽  
pp. 445 ◽  
Author(s):  
G. Dean Price ◽  
Susanne von Caemmerer ◽  
John R. Evans ◽  
Katharina Siebke ◽  
Jan M. Anderson ◽  
...  
Keyword(s):  
Protein Content ◽  
Transgenic Tobacco ◽  
Co2 Assimilation ◽  
High Light ◽  
Cytochrome F ◽  
Assimilation Rate ◽  
Wild Type ◽  
Co2 Assimilation Rate ◽  
Cytochrome Bf Complex ◽  
Rieske Fes Protein

We have used transgenic tobacco (Nicotiana tabacum L. cv. W38) plants expressing an antisense gene directed against the transcript of the Rieske FeS protein of the chloroplast bf complex to examine the effect a reduction in chloroplast Rieske FeS content on leaf gas exchange and photosynthetic metabolite pools. Plants with chloroplast Rieske FeS protein content ranging from 5 to 80% of wild-type were analysed. CO2 assimilation rate declined linearly with the reduction in Rieske FeS content when expressed on a leaf area basis. In contrast to photosynthesis, there was no change in stomatal conductance except for plants with less than 10% of wild-type Rieske FeS content. There was a close correlation between Rieske FeS content and cytochrome f content, showing that the reduction in Rieske FeS content lead to a similar reduction in other components of the cytochrome bf complex. While lower Rieske FeS content was associated with declines in chlorophyll content, ATPδ subunit and ribulosebisphosphate carboxylase–oxygenase (Rubisco) contents, these declines were considerably smaller than the reduction in cytochrome bf content. As Rieske FeS content was reduced, there was a slight lowering of the chlorophyll a/b ratio. Lower CO2 assimilation rates at ambient CO2 and high light were associated with dramatic reductions in ribulose bisphosphate (RuBP) and modest declines in 3- phosphoglycerate (PGA). Rubisco carbamylation declined to 40–50% in plants with Rieske FeS content lower than 20% of wild-type. We conclude that, at high light, a reduction in chloroplast Rieske FeS protein content leads to inhibition of CO2 assimilation rate via reductions in the rate of RuBP regeneration caused by a restriction in electron transport and via effects on in vivo Rubisco activity.

scholarly journals Overexpression of Rubisco Activase Decreases the Photosynthetic CO2 Assimilation Rate by Reducing Rubisco Content in Rice Leaves

2012 ◽  
Vol 53 (6) ◽  
pp. 976-986 ◽  
Author(s):  
Hiroshi Fukayama ◽  
Chiaki Ueguchi ◽  
Kaoru Nishikawa ◽  
Nobuaki Katoh ◽  
Chie Ishikawa ◽  
...  
Keyword(s):  
Rubisco Activase ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Co2 Assimilation Rate ◽  
Rice Leaves ◽  
Photosynthetic Co2 Assimilation

scholarly journals Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

2013 ◽  
Vol 48 (9) ◽  
pp. 1210-1219 ◽  
Author(s):  
Muhammad Iqbal ◽  
Muhammad Ashraf
Keyword(s):  
Abscisic Acid ◽  
Gas Exchange ◽  
Acid Concentration ◽  
Spring Wheat ◽  
Indoleacetic Acid ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Co2 Assimilation Rate ◽  
Net Co2 Assimilation Rate ◽  
Net Co2 Assimilation

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

scholarly journals Foliar phosphorus supply and CO2 assimilation in common bean (Phaseolus vulgaris L.) under water deficit

2006 ◽  
Vol 18 (3) ◽  
pp. 407-411 ◽  
Author(s):  
Mauro G. dos Santos ◽  
Rafael V. Ribeiro ◽  
Marcelo G. Teixeira ◽  
Ricardo F. de Oliveira ◽  
Carlos Pimentel
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Water Deficit ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Phaseolus Vulgaris L ◽  
Co2 Assimilation Rate ◽  
Net Co2 Assimilation ◽  
Foliar Phosphorus ◽  
Regulation Of Photosynthesis

Two common bean cultivars were grown in pots under greenhouse conditions. Plants were submitted to a foliar Pi spray two days before suspending irrigation, what enhanced net CO2 assimilation rate of Ouro Negro cultivar but did not change significantly the photosynthesis of Carioca cultivar under both water deficit and rehydration periods. The results revealed that a foliar Pi spray induced an up-regulation of photosynthesis in common bean under mild water deficit, with this effect being genotype-dependent.

scholarly journals Effects of water deficit on growth and physiology of young Conocarpus erectus L. and Ficus benjamina L. Saplings

2019 ◽  
Vol 48 (4) ◽  
pp. 1215-1221
Author(s):  
Zikria Zafar ◽  
Fahad Rasheed ◽  
Muhammad Abdullah ◽  
Mir Md Abdus Salam ◽  
Muhammad Mohsin
Keyword(s):  
Water Deficit ◽  
Biomass Production ◽  
Root Biomass ◽  
Growth Parameters ◽  
Co2 Assimilation ◽  
Total Biomass ◽  
Assimilation Rate ◽  
Ficus Benjamina ◽  
Co2 Assimilation Rate ◽  
Conocarpus Erectus

A greenhouse experiment was conducted to investigate the effects of water deficit on growth and physiological parameters of Ficus benjamina and Conocarpus erectus. The results revealed that all growth parameters such as plant height, stem diameter, no. of leaves, no. of branches and chlorophyll contents significantly decreased under water deficit condition. Interestingly, although leaf, stem and total biomass production and allocation decreased significantly under water deficit, but root biomass production and allocation increased significantly. Similarly, stomatal conductance to water vapor decreased significantly and CO2 assimilation rate remained similar to control under water deficit condition. Resultantly, a significant increase in water use efficiency was evident in both species under water deficit condition. These results suggested that, in spite of a significant decrease in biomass production, young Conocarpus erectus and Ficus benjamina can tolerate water deficit which is due to sustained CO2 assimilation rate and increase in root biomass.

A consistent CO2 assimilation rate and an enhanced root development drives the tolerance mechanism in Ziziphus jujuba under soil water deficit

2020 ◽  
Vol 34 (4) ◽  
pp. 392-404 ◽  
Author(s):  
Muhammad Azeem Sabir ◽  
Fahad Rasheed ◽  
Zikria Zafar ◽  
Imran Khan ◽  
Muhammad Farrakh Nawaz ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Root Development ◽  
Co2 Assimilation ◽  
Soil Water Deficit ◽  
Assimilation Rate ◽  
Tolerance Mechanism ◽  
Co2 Assimilation Rate ◽  
Ziziphus Jujuba
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