Limits...
The Stable Level of Glutamine synthetase 2 Plays an Important Role in Rice Growth and in Carbon-Nitrogen Metabolic Balance.

Bao A, Zhao Z, Ding G, Shi L, Xu F, Cai H - Int J Mol Sci (2015)

Bottom Line: The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems.Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage.These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth.

View Article: PubMed Central - PubMed

Affiliation: Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China. baoaili19870212@163.com.

ABSTRACT
Glutamine synthetase 2 (GS2) is a key enzyme involved in the ammonium metabolism in plant leaves. In our previous study, we obtained GS2-cosuppressed plants, which displayed a normal growth phenotype at the seedling stage, while at the tillering stage they showed a chlorosis phenotype. In this study, to investigate the chlorosis mechanism, we systematically analyzed the plant growth, carbon-nitrogen metabolism and gene expressions between the GS2-cosuppressed rice and wild-type plants. The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems. Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage. The analysis of the metabolic profile showed a significant increase of sugars and organic acids. Additionally, gene expression patterns were different in root and leaf of GS2-cosuppressed plants between the seedling and tillering stage. These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth.

No MeSH data available.


Related in: MedlinePlus

The fold change corresponds to the ratio of the concentration of individual metabolites involved in carbon and nitrogen metabolism in the GS2-cosuppressed plants relative to the wild-type plants for the uppermost leaves and roots at the tillering stage under N condition. Red dots indicate increased metabolites, and blue triangles indicate decreased metabolites. Glc, glucose; Suc, sucrose; Fru, fructose; F6P, frutose-6-P; G6P, glucose-6-P; G1P, glucose-1-P; Gal, galactose; Ino, inositol; AA, ascorbic acid; Ara, arabinose; Xyl, xylitol; 3PG, 3-P-glycerate; PEP, phosphoenolpyruvate; Pyr, pyruvate; Ace-CoA, acetyl-CoA; Cit, citrate; Aco, aconitase; KG, ketoglutarate; Succ, succinate; Fum, fumarate; Mal, malate; Oxa, oxaloacetate; Glu, glutamate; Gln, glutamine; Arg, arginine; Pro, proline; Orn, ornithine; GABA, aminobutyric; Asp, aspartate; Asn, asparagine; Ile, isoleucine; Met, methionine; Thr, threonine; Ala, alanine; Val, valine; Leu, leucine; Phe, phenylalanine; Try, tryptophan; Ser, serine; Gly, glycine; Cys, cysteine.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4490469&req=5

ijms-16-12713-f005: The fold change corresponds to the ratio of the concentration of individual metabolites involved in carbon and nitrogen metabolism in the GS2-cosuppressed plants relative to the wild-type plants for the uppermost leaves and roots at the tillering stage under N condition. Red dots indicate increased metabolites, and blue triangles indicate decreased metabolites. Glc, glucose; Suc, sucrose; Fru, fructose; F6P, frutose-6-P; G6P, glucose-6-P; G1P, glucose-1-P; Gal, galactose; Ino, inositol; AA, ascorbic acid; Ara, arabinose; Xyl, xylitol; 3PG, 3-P-glycerate; PEP, phosphoenolpyruvate; Pyr, pyruvate; Ace-CoA, acetyl-CoA; Cit, citrate; Aco, aconitase; KG, ketoglutarate; Succ, succinate; Fum, fumarate; Mal, malate; Oxa, oxaloacetate; Glu, glutamate; Gln, glutamine; Arg, arginine; Pro, proline; Orn, ornithine; GABA, aminobutyric; Asp, aspartate; Asn, asparagine; Ile, isoleucine; Met, methionine; Thr, threonine; Ala, alanine; Val, valine; Leu, leucine; Phe, phenylalanine; Try, tryptophan; Ser, serine; Gly, glycine; Cys, cysteine.

Mentions: To study the individual metabolites involved in the carbon and nitrogen metabolic pathway in detail, we analyzed the sugars, organic acids and free amino acids in the root and leaf tissues of GS2-cosuppressed plants and wild-type plants at the tillering stage under different N conditions. Figure 5 and Supplementary Figure S1 display the fold change corresponding to the ratio of GS2-cosuppressed plants/wild-type plants, calculated using the concentrations of these individual metabolites. Dramatic increases in the sugars, organic acids and free amino acids were observed in both the leaf and root tissues of the GS2-cosuppressed plants compared to the wild-type plants, especially for ascorbic acid (>37.7-fold), succinate (>312.4-fold) and methionine (>410.3-fold) in the leaf and xylitol (>46.3-fold), ascorbic acid (>14.2-fold), pyruvate (>808.1-fold) and ornithine (>19.9-fold) in the root (Figure 5; Supplementary Figure S1). Meanwhile, several metabolites had dramatically decreased concentrations, including glutaric acid (<0.10-fold) and glycine (<0.07-fold) in the leaf and glutamine (<0.04-fold), alanine (<0.004-fold) and leucine (<0.0006-fold) in the root (Figure 5; Supplementary Figure S1). However, the concentrations of total sugars, total organic acids and total free amino acids increased only slightly, a fold change ranging from 2.0–3.7 (data not shown here).


The Stable Level of Glutamine synthetase 2 Plays an Important Role in Rice Growth and in Carbon-Nitrogen Metabolic Balance.

Bao A, Zhao Z, Ding G, Shi L, Xu F, Cai H - Int J Mol Sci (2015)

The fold change corresponds to the ratio of the concentration of individual metabolites involved in carbon and nitrogen metabolism in the GS2-cosuppressed plants relative to the wild-type plants for the uppermost leaves and roots at the tillering stage under N condition. Red dots indicate increased metabolites, and blue triangles indicate decreased metabolites. Glc, glucose; Suc, sucrose; Fru, fructose; F6P, frutose-6-P; G6P, glucose-6-P; G1P, glucose-1-P; Gal, galactose; Ino, inositol; AA, ascorbic acid; Ara, arabinose; Xyl, xylitol; 3PG, 3-P-glycerate; PEP, phosphoenolpyruvate; Pyr, pyruvate; Ace-CoA, acetyl-CoA; Cit, citrate; Aco, aconitase; KG, ketoglutarate; Succ, succinate; Fum, fumarate; Mal, malate; Oxa, oxaloacetate; Glu, glutamate; Gln, glutamine; Arg, arginine; Pro, proline; Orn, ornithine; GABA, aminobutyric; Asp, aspartate; Asn, asparagine; Ile, isoleucine; Met, methionine; Thr, threonine; Ala, alanine; Val, valine; Leu, leucine; Phe, phenylalanine; Try, tryptophan; Ser, serine; Gly, glycine; Cys, cysteine.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490469&req=5

ijms-16-12713-f005: The fold change corresponds to the ratio of the concentration of individual metabolites involved in carbon and nitrogen metabolism in the GS2-cosuppressed plants relative to the wild-type plants for the uppermost leaves and roots at the tillering stage under N condition. Red dots indicate increased metabolites, and blue triangles indicate decreased metabolites. Glc, glucose; Suc, sucrose; Fru, fructose; F6P, frutose-6-P; G6P, glucose-6-P; G1P, glucose-1-P; Gal, galactose; Ino, inositol; AA, ascorbic acid; Ara, arabinose; Xyl, xylitol; 3PG, 3-P-glycerate; PEP, phosphoenolpyruvate; Pyr, pyruvate; Ace-CoA, acetyl-CoA; Cit, citrate; Aco, aconitase; KG, ketoglutarate; Succ, succinate; Fum, fumarate; Mal, malate; Oxa, oxaloacetate; Glu, glutamate; Gln, glutamine; Arg, arginine; Pro, proline; Orn, ornithine; GABA, aminobutyric; Asp, aspartate; Asn, asparagine; Ile, isoleucine; Met, methionine; Thr, threonine; Ala, alanine; Val, valine; Leu, leucine; Phe, phenylalanine; Try, tryptophan; Ser, serine; Gly, glycine; Cys, cysteine.
Mentions: To study the individual metabolites involved in the carbon and nitrogen metabolic pathway in detail, we analyzed the sugars, organic acids and free amino acids in the root and leaf tissues of GS2-cosuppressed plants and wild-type plants at the tillering stage under different N conditions. Figure 5 and Supplementary Figure S1 display the fold change corresponding to the ratio of GS2-cosuppressed plants/wild-type plants, calculated using the concentrations of these individual metabolites. Dramatic increases in the sugars, organic acids and free amino acids were observed in both the leaf and root tissues of the GS2-cosuppressed plants compared to the wild-type plants, especially for ascorbic acid (>37.7-fold), succinate (>312.4-fold) and methionine (>410.3-fold) in the leaf and xylitol (>46.3-fold), ascorbic acid (>14.2-fold), pyruvate (>808.1-fold) and ornithine (>19.9-fold) in the root (Figure 5; Supplementary Figure S1). Meanwhile, several metabolites had dramatically decreased concentrations, including glutaric acid (<0.10-fold) and glycine (<0.07-fold) in the leaf and glutamine (<0.04-fold), alanine (<0.004-fold) and leucine (<0.0006-fold) in the root (Figure 5; Supplementary Figure S1). However, the concentrations of total sugars, total organic acids and total free amino acids increased only slightly, a fold change ranging from 2.0–3.7 (data not shown here).

Bottom Line: The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems.Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage.These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth.

View Article: PubMed Central - PubMed

Affiliation: Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China. baoaili19870212@163.com.

ABSTRACT
Glutamine synthetase 2 (GS2) is a key enzyme involved in the ammonium metabolism in plant leaves. In our previous study, we obtained GS2-cosuppressed plants, which displayed a normal growth phenotype at the seedling stage, while at the tillering stage they showed a chlorosis phenotype. In this study, to investigate the chlorosis mechanism, we systematically analyzed the plant growth, carbon-nitrogen metabolism and gene expressions between the GS2-cosuppressed rice and wild-type plants. The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems. Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage. The analysis of the metabolic profile showed a significant increase of sugars and organic acids. Additionally, gene expression patterns were different in root and leaf of GS2-cosuppressed plants between the seedling and tillering stage. These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth.

No MeSH data available.


Related in: MedlinePlus