Sandbox Reserved 660: Difference between revisions

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Ligase in the enzymology, is is an enzyme that catalyze the joining of two large molecule by forming new chemical bond. In the process of catalysis, there is always hydrolysis of small molecule group accompanying. 4CL ligase, sepcifically, catalyzes the formation of carbon sulfur bond between two reactants.

4CL is one of the key enzyme regulating the synthesis of monolignols in the lignin pathway. Lignin is an unique and complex phenylpropanoid polymer which plays key role in plant development and response to the environment. Lignin is typically polymerized from 3 phenylpropanoid mononers , p-coumaryl (H), coniferyl (G) and sinapyl (S). The relative amounts of these 3 monomers found in lignin show plant specificity and 4CL is one of the main enzymes participating the formation these 3 monomers in the regulatory network of the monolignol pathway and has significant effect on the S/G ratio which is substantial to the lignin formation situation in the plant. There is report showing that the 4CL gene knock-down will result in the lignin reduction[]. In other words, the activity of 4CL determines the overall carbon flow of the phenylpropanoid pathway. For this reason, 4CL has been focused on the genetic engineering regulation about the plants products quality improvement.

4CL is one of the key enzyme regulating the synthesis of monolignols in the lignin pathway. Lignin is an unique and complex phenylpropanoid polymer which plays key role in plant development and response to the environment. Lignin is typically polymerized from 3 phenylpropanoid mononers , p-coumaryl (H), coniferyl (G) and sinapyl (S)[1]. The relative amounts of these 3 monomers found in lignin show plant specificity and 4CL is one of the main enzymes participating the formation these 3 monomers in the regulatory network of the monolignol pathway and has significant effect on the S/G ratio which is substantial to the lignin formation situation in the plant. There is report showing that the 4CL gene knock-down will result in the lignin reduction[]. In other words, the activity of 4CL determines the overall carbon flow of the phenylpropanoid pathway. For this reason, 4CL has been focused on the genetic engineering regulation about the plants products quality improvement.

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4-Coumarate-coenzyme A ligase (4CL) is an enzyme that functions early in the general phenylpropanoid pathway by producing the monolignol precursor p-coumaroyl-CoA. 4CL silencing in angiosperm species such as tobacco, Arabidopsis and Populus tremuloides causes lignin reductions in the range of 25% to 45%. However, the impacts of these manipulations on lignin composition varied. 4CL silencing in tobacco preferentially depleted syringyl (S) lignin units, which are prominent in wood fibers. 4CL silencing in Arabidopsis depleted only guaiacyl (G) lignin units, which are enriched in vessel elements, whereas silencing of 4CL in P.tremuloides had no impact on the S-G ratio. An increase in the S-G ratio in P.tremuloides was only recorded when 4CL silencing was combined with the over expression of coniferaldehyde 5-hydroxylase. These differences in lignin composition could be the consequence of silencing 4CL isoforms with different substrate preferences, or they could reflect the in adequacies or limitations of analytical procedures used for lignin analysis.

==References==

1. Ralph, J., Brunow, G., Harris, P. J., Dixon, R. A., Schatz, P. F., and Boerjan, W. 2008. Lignification: Are lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication? In F. Daayf, A. El Hadrami, L. Adam and G. M. and Ballance (eds.), Recent Advances in Polyphenol Research. Wiley-Blackwell Publishing, Oxford, UK.

2.

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@@ Line 13: / Line 13: @@
 Ligase in the enzymology, is is an enzyme that catalyze the joining of two large molecule by forming new chemical bond. In the process of catalysis, there is always hydrolysis of small molecule group accompanying. 4CL ligase, sepcifically, catalyzes the formation of carbon sulfur bond between two reactants.
-CL is one of the key enzyme regulating the synthesis of monolignols in the lignin pathway. Lignin is an unique and complex phenylpropanoid polymer which plays key role in plant development and response to the environment. Lignin is typically polymerized from 3 phenylpropanoid mononers , p-coumaryl  (H),  coniferyl  (G)  and  sinapyl (S). The relative amounts of these 3 monomers found in lignin show plant specificity and 4CL is one of the main enzymes participating the formation these 3 monomers in the regulatory network of the monolignol pathway and has significant effect on the S/G ratio which is substantial to the lignin formation situation in the plant. There is report showing that the 4CL gene knock-down will result in the lignin reduction[]. In other words, the activity of 4CL determines the overall carbon flow of the phenylpropanoid pathway. For this reason, 4CL has been focused on the genetic engineering regulation about the plants products quality improvement.
+CL is one of the key enzyme regulating the synthesis of monolignols in the lignin pathway. Lignin is an unique and complex phenylpropanoid polymer which plays key role in plant development and response to the environment. Lignin is typically polymerized from 3 phenylpropanoid mononers , p-coumaryl  (H),  coniferyl  (G)  and  sinapyl (S)[1]. The relative amounts of these 3 monomers found in lignin show plant specificity and 4CL is one of the main enzymes participating the formation these 3 monomers in the regulatory network of the monolignol pathway and has significant effect on the S/G ratio which is substantial to the lignin formation situation in the plant. There is report showing that the 4CL gene knock-down will result in the lignin reduction[]. In other words, the activity of 4CL determines the overall carbon flow of the phenylpropanoid pathway. For this reason, 4CL has been focused on the genetic engineering regulation about the plants products quality improvement.
@@ Line 35: / Line 35: @@
 -Coumarate-coenzyme A ligase (4CL) is an enzyme that functions early in the general  phenylpropanoid pathway by producing the monolignol precursor p-coumaroyl-CoA. 4CL silencing in angiosperm species such as tobacco, Arabidopsis and Populus tremuloides causes lignin reductions in the range of 25% to 45%. However, the impacts of these manipulations on lignin composition varied. 4CL silencing in tobacco preferentially depleted syringyl (S) lignin units, which are prominent in wood fibers. 4CL silencing in Arabidopsis depleted only guaiacyl (G) lignin units, which are enriched in vessel elements, whereas silencing of 4CL in P.tremuloides had no impact on the S-G ratio. An increase in the S-G ratio in P.tremuloides was only recorded when 4CL silencing was combined with the over expression of coniferaldehyde 5-hydroxylase. These differences in lignin composition could be the consequence of silencing 4CL isoforms with different substrate preferences, or they could reflect the in adequacies or limitations of analytical procedures used for lignin analysis.
+==References==
+. Ralph, J., Brunow, G., Harris, P. J., Dixon, R. A., Schatz, P. F., and Boerjan, W. 2008. Lignification: Are  lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication? In F. Daayf, A. El Hadrami, L. Adam and G. M. and Ballance (eds.), Recent Advances in Polyphenol Research. Wiley-Blackwell Publishing, Oxford, UK.
+.