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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 concentration of soluble carbohydrates in the roots, stems and uppermost leaves of GS2-cosuppressed plants (Co-sup-GS2) and wild-type plants (WT) at the seedling stage (A) and the tillering stage (B) under N (NH4NO3), G (Gln) and N + G (NH4NO3 + Gln) conditions. Values are the mean ± SD from three biological replicated plant materials. *, ** Significant differences at the level of p = 0.05 and p = 0.01, respectively.
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ijms-16-12713-f004: The concentration of soluble carbohydrates in the roots, stems and uppermost leaves of GS2-cosuppressed plants (Co-sup-GS2) and wild-type plants (WT) at the seedling stage (A) and the tillering stage (B) under N (NH4NO3), G (Gln) and N + G (NH4NO3 + Gln) conditions. Values are the mean ± SD from three biological replicated plant materials. *, ** Significant differences at the level of p = 0.05 and p = 0.01, respectively.

Mentions: In contrast, there was a lower concentration of soluble carbohydrates in the GS2-cosuppressed plants at the seedling stage, while there was a higher concentration of soluble carbohydrates in the GS2-cosuppressed plants at the tillering stage when compared to the wild-type plants (Figure 4). For example, at the seedling stage, compared to the wild-type plants, there were 30.0% and 46.7% decreases in the stem soluble carbohydrates of GS2-cosuppressed plants under the N and G conditions, respectively; and there were 25.7%, 31.8% and 23.2% decreases in soluble carbohydrates in the leaves under the N, G and N + G conditions, respectively; (Figure 4A). At the tillering stage, compared to the wild-type plants, there were 99.9% and 178.0% increases in the soluble carbohydrates in the stem, and there were 98.3% and 84.6% increases in the soluble carbohydrates in the leaves of GS2-cosuppressed plants under the N and G conditions, respectively (Figure 4B). These results suggested that the altered GS2 expression level (higher GS2 expression level at the seedling stage and lower GS2 expression level at the tillering stage) affected the carbon and nitrogen metabolic status. There was an imbalance between the soluble protein and carbohydrate concentrations in the GS2-cosuppressed plants, especially in the stems and leaves.


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 concentration of soluble carbohydrates in the roots, stems and uppermost leaves of GS2-cosuppressed plants (Co-sup-GS2) and wild-type plants (WT) at the seedling stage (A) and the tillering stage (B) under N (NH4NO3), G (Gln) and N + G (NH4NO3 + Gln) conditions. Values are the mean ± SD from three biological replicated plant materials. *, ** Significant differences at the level of p = 0.05 and p = 0.01, respectively.
© Copyright Policy
Related In: Results  -  Collection

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

ijms-16-12713-f004: The concentration of soluble carbohydrates in the roots, stems and uppermost leaves of GS2-cosuppressed plants (Co-sup-GS2) and wild-type plants (WT) at the seedling stage (A) and the tillering stage (B) under N (NH4NO3), G (Gln) and N + G (NH4NO3 + Gln) conditions. Values are the mean ± SD from three biological replicated plant materials. *, ** Significant differences at the level of p = 0.05 and p = 0.01, respectively.
Mentions: In contrast, there was a lower concentration of soluble carbohydrates in the GS2-cosuppressed plants at the seedling stage, while there was a higher concentration of soluble carbohydrates in the GS2-cosuppressed plants at the tillering stage when compared to the wild-type plants (Figure 4). For example, at the seedling stage, compared to the wild-type plants, there were 30.0% and 46.7% decreases in the stem soluble carbohydrates of GS2-cosuppressed plants under the N and G conditions, respectively; and there were 25.7%, 31.8% and 23.2% decreases in soluble carbohydrates in the leaves under the N, G and N + G conditions, respectively; (Figure 4A). At the tillering stage, compared to the wild-type plants, there were 99.9% and 178.0% increases in the soluble carbohydrates in the stem, and there were 98.3% and 84.6% increases in the soluble carbohydrates in the leaves of GS2-cosuppressed plants under the N and G conditions, respectively (Figure 4B). These results suggested that the altered GS2 expression level (higher GS2 expression level at the seedling stage and lower GS2 expression level at the tillering stage) affected the carbon and nitrogen metabolic status. There was an imbalance between the soluble protein and carbohydrate concentrations in the GS2-cosuppressed plants, especially in the stems and leaves.

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