scholarly journals Regulation of Sucrose Synthesis by Cytoplasmic Fructosebisphosphatase and Sucrose Phosphate Synthase during Photosynthesis in Varying Light and Carbon Dioxide

1983 ◽  
Vol 72 (3) ◽  
pp. 767-774 ◽  
Author(s):  
Mark Stitt ◽  
Wolfgang Wirtz ◽  
Hans W. Heldt
Keyword(s):  
Carbon Dioxide ◽  
Sucrose Phosphate Synthase ◽  
Sucrose Synthesis ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

Control analysis of photosynthetic sucrose synthesis: assignment of elasticity coefficients and flux-control coefficients to the cytosolic fructose 1,6-bisphosphatase and sucrose phosphate synthase

1989 ◽  
Vol 323 (1216) ◽  
pp. 327-338 ◽  
Keyword(s):  
Sucrose Phosphate Synthase ◽  
Control Analysis ◽  
Sucrose Synthesis ◽  
Flux Control ◽  
Fructose 1,6 Bisphosphatase ◽  
Flux Control Coefficients ◽  
Sucrose Phosphate ◽  
Control Coefficients ◽  
Phosphate Synthase

The use of elasticity coefficients and flux-control coefficients in a quantitative treatment of control is discussed, with photosynthetic sucrose synthesis as an example. Experimental values for elasticities for the cytosolic fructose 1,6-bisphosphatase and sucrose phosphate synthase are derived from their in vitro properties, and from an analysis of the in vivo relation between fluxes and metabolite levels. An empirical factor α , describing the response of the fructose 2,6-bisphosphate regulator cycle to fructose 6-phosphate is described, and an expression is derived relating α to the elasticities of the enzymes involved in this regulator cycle. The in vivo values for elasticities and α are then used in a modified form of the connectivity theorem to estimate the flux control coefficients of the cytosolic fructose 1,6-bisphosphatase and sucrose phosphate synthase during rapid photosynthetic sucrose synthesis.

Regulation of sucrose-phosphate synthase in wheat (Triticum aestivum) leaves

2004 ◽  
Vol 31 (7) ◽  
pp. 685 ◽  
Author(s):  
Stephen J. Trevanion ◽  
C. Kate Castleden ◽  
Christine H. Foyer ◽  
Robert T. Furbank ◽  
W. Paul Quick ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Feedback Inhibition ◽  
Sucrose Phosphate Synthase ◽  
High Light ◽  
Sucrose Synthesis ◽  
Short Term ◽  
Cereal Species ◽  
Wheat Leaves ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

The regulation of sucrose-phosphate synthase (SPS, E.C. 2.4.1.14), a key enzyme of sucrose synthesis, was investigated in wheat (Triticum aestivum L.) leaves. Wheat SPS was activated in the light, with an increased affinity for its substrates and the activator glucose-6-phosphate, reduced sensitivity to inhibition by Pi, but no change in maximum catalytic activity. Based on these properties, assays to measure the total activity and activation state of the enzyme were established and validated using several different wheat cultivars, grown under different environmental conditions. As found in previous studies on other species, e.g. spinach, activation appeared to be linked to the prevailing rate of photosynthesis rather than light per se. Long-term exposure to higher light levels increased total SPS activity in the leaves, and some experiments indicated that this response could occur within 1 h of exposure of low-light-grown plants to high light. However, activation of pre-existing enzyme was a more common short-term response to high light. Wheat, like many important cereal species, stores a large amount of sucrose in its leaves. In contrast with spinach, which stores more starch in its leaves, accumulation of sucrose in wheat leaves did not lead to inactivation of SPS or inhibition of sucrose synthesis. In conclusion, the mechanisms linking the rates of sucrose synthesis and photosynthetic CO2 fixation in wheat leaves appear to be similar to those in other species, but the mechanisms involved in short-term feedback inhibition of sucrose synthesis by sucrose, found in starch-storing species, are lacking in wheat.

scholarly journals Sucrose Synthesis in the Nitrogen-Fixing Cyanobacterium Anabaena sp. Strain PCC 7120 Is Controlled by the Two-Component Response Regulator OrrA

2014 ◽  
Vol 80 (18) ◽  
pp. 5672-5679 ◽  
Author(s):  
Shigeki Ehira ◽  
Satoshi Kimura ◽  
Shogo Miyazaki ◽  
Masayuki Ohmori
Keyword(s):  
Salt Stress ◽  
Response Regulator ◽  
Sucrose Phosphate Synthase ◽  
Early Response ◽  
Sucrose Synthesis ◽  
Nitrogen Fixing ◽  
Content Type ◽  
Pcc 7120 ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

ABSTRACTThe filamentous, nitrogen-fixing cyanobacteriumAnabaenasp. strain PCC 7120 accumulates sucrose as a compatible solute against salt stress. Sucrose-phosphate synthase activity, which is responsible for the sucrose synthesis, is increased by salt stress, but the mechanism underlying the regulation of sucrose synthesis remains unknown. In the present study, a response regulator, OrrA, was shown to control sucrose synthesis. Expression ofspsA, which encodes a sucrose-phosphate synthase, andsusAandsusB, which encode sucrose synthases, was induced by salt stress. In theorrAdisruptant, salt induction of these genes was completely abolished. The cellular sucrose level of theorrAdisruptant was reduced to 40% of that in the wild type under salt stress conditions. Moreover, overexpression oforrAresulted in enhanced expression ofspsA,susA, andsusB, followed by accumulation of sucrose, without the addition of NaCl. We also found that SigB2, a group 2 sigma factor of RNA polymerase, regulated the early response to salt stress under the control of OrrA. It is concluded that OrrA controls sucrose synthesis in collaboration with SigB2.

scholarly journals TRANSFORMASI GEN SUCROSE PHOSPHATE SYNTHASE (SoSPS1) MENGGUNAKAN Agrobacterium tumefaciens UNTUK MENINGKATKAN SINTESIS SUKROSA PADA TANAMAN TEBU (Saccharum officinarum L.)

2007 ◽  
Vol 12 (2) ◽  
pp. 137-143
Author(s):  
Miswar Miswar ◽  
Bambang Sugiharto ◽  
Joedoro Soedarsono ◽  
Sukarti Moeljapawiro
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Starch Content ◽  
Sucrose Phosphate Synthase ◽  
Saccharum Officinarum ◽  
Invertase Activity ◽  
Pcr Analysis ◽  
Sucrose Synthesis ◽  
Transgenic Sugarcane ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

Sucrose phosphate synthase (SPS EC 2.3.1.14) plays an important role in partition of assimilated carbon in most plants. SPS catalyses the penultimate reaction in the pathway of sucrose synthesis, in which sucrose-6-phosphate (Suc6P) is synthesized from UDPglucose (UDPG) and fructose-6-P (Fru6P). To increase the capacity of sugarcane in sucrose synthesis, spindle leaves of sugarcane cv R579 were transformed with cDNA SoSPS1 from sugarcane under the control of constitutive promoter (35S CaMV) that constructed in pBI 121 (pKYS) using Agrobacterium tumefaciens. Based on PCR analysis, we have detected the existence of SPS transgene in some lines of transformed sugarcane, called line 4, 5, 6, and 7. The SPS transgene in transformed sugarcane could be expressed into translation level and increased the amount of leaves SPS protein, so the activity of leaves SPS was higher than wild type sugarcane as control. The transformed sugarcane line 4, 5, 6, and 7 showed 1.4–2.9 fold increases in SPS activity and 1,76–2,2 fold increases in leaves sucrose content. Increasing in SPS activity in transgenic sugarcane was coupled by the increase in invertase activity and ratio between sucrose and starch content.

Short-term water stress leads to a stimulation of sucrose synthesis by activating sucrose-phosphate synthase

Planta ◽  
1989 ◽  
Vol 177 (4) ◽  
pp. 535-546 ◽  
Author(s):  
Paul Quick ◽  
Gabi Siegl ◽  
Ekkehard Neuhaus ◽  
Regina Feil ◽  
Mark Stitt
Keyword(s):  
Water Stress ◽  
Sucrose Phosphate Synthase ◽  
Sucrose Synthesis ◽  
Short Term ◽  
Sucrose Phosphate ◽  
Stimulation Of ◽  
Phosphate Synthase
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