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Comparative metabolic responses and adaptive strategies of wheat (Triticum aestivum) to salt and alkali stress.

Guo R, Yang Z, Li F, Yan C, Zhong X, Liu Q, Xia X, Li H, Zhao L - BMC Plant Biol. (2015)

Bottom Line: High-pH of alkali stress induced the most of phosphate and metal ions to precipitate; as a result, the availability of nutrients significantly declined.These outcomes correspond to specific detrimental effects of a highly pH environment.Alkali stress (at high pH) significantly inhibited photosynthetic rate; thus, sugar production was reduced, N metabolism was limited, amino acid production was reduced, and glycolysis was inhibited.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environment and Sustainable Development in Agriculture (IEDA), Chinese Academy of Agricultural Sciences (CAAS)/Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Beijing, 100081, P.R. China. guor219@yahoo.com.

ABSTRACT

Background: It is well known that salinization (high-pH) has been considered as a major environmental threat to agricultural systems. The aim of this study was to investigate the differences between salt stress and alkali stress in metabolic profiles and nutrient accumulation of wheat; these parameters were also evaluated to determine the physiological adaptive mechanisms by which wheat tolerates alkali stress.

Results: The harmful effect of alkali stress on the growth and photosynthesis of wheat were stronger than those of salt stress. High-pH of alkali stress induced the most of phosphate and metal ions to precipitate; as a result, the availability of nutrients significantly declined. Under alkali stress, Ca sharply increased in roots, however, it decreased under salt stress. In addition, we detected the 75 metabolites that were different among the treatments according to GC-MS analysis, including organic acids, amino acids, sugars/polyols and others. The metabolic data showed salt stress and alkali stress caused different metabolic shifts; alkali stress has a stronger injurious effect on the distribution and accumulation of metabolites than salt stress. These outcomes correspond to specific detrimental effects of a highly pH environment.

Conclusions: Ca had a significant positive correlation with alkali tolerates, and increasing Ca concentration can immediately trigger SOS Na exclusion system and reduce the Na injury. Salt stress caused metabolic shifts toward gluconeogenesis with increased sugars to avoid osmotic stress; energy in roots and active synthesis in leaves were needed by wheat to develop salt tolerance. Alkali stress (at high pH) significantly inhibited photosynthetic rate; thus, sugar production was reduced, N metabolism was limited, amino acid production was reduced, and glycolysis was inhibited.

No MeSH data available.


Related in: MedlinePlus

Global comparison of metabolic profiles in leaves and roots under no salinity stress (CK), salt stress (SS), and alkali stress (AS). A total of 77 metabolites were identified in this study, and the numbers in the figure indicate the numbers of metabolites with no significant difference in their contents for each comparison
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Fig4: Global comparison of metabolic profiles in leaves and roots under no salinity stress (CK), salt stress (SS), and alkali stress (AS). A total of 77 metabolites were identified in this study, and the numbers in the figure indicate the numbers of metabolites with no significant difference in their contents for each comparison

Mentions: Based on the results of PCA and OPLS-DA, the responses of metabolites to salt stress and alkali stress were different in leaves and roots. The response of 11 and 5 metabolites under salt stress and 7 and 36 metabolites under alkali stress remarkably increased and decreased, respectively, in leaves of wheat seedlings (Fig. 4, leaves). Following pre-stress, salt stress caused an increase in levels of glucose, glucose-6-P, fructose-6-P, 3-PGA, and PEP, which are involved in glycolysis, and in levels of fructose, trehalose, proline, valine, isoleucine, and leucine. By contrast, salt stress resulted in a decrease in levels of fumaric acid and malic acid, which are involved in the TCA cycle, and in levels of maltose, shikimic acid, and quinic acid, which are involved in the shikimate pathway. Under alkali stress, the levels of some amino acids and sugars increased, including proline, lysine, sucrose, sorbitol, trehalose, lyxose, and gentiobiose; however, glycolysis was significantly inhibited under alkali stress, thereby decreasing the levels of glucose-6-P, fructose-6-P, and PEP. Furthermore, the TCA cycle, which is associated with glycolysis pathway, was inhibited under alkali stress, as shown by lower citric acid, α-ketoglutaric acid, and fumaric acid levels than the control plants. Shikimate pathway and GABA shunt metabolites were inhibited under alkali stress, resulting in a decrease in shikimic acid, quinic acid, phenylalanine, GABA, and glutamate levels (Table 1).Fig. 4


Comparative metabolic responses and adaptive strategies of wheat (Triticum aestivum) to salt and alkali stress.

Guo R, Yang Z, Li F, Yan C, Zhong X, Liu Q, Xia X, Li H, Zhao L - BMC Plant Biol. (2015)

Global comparison of metabolic profiles in leaves and roots under no salinity stress (CK), salt stress (SS), and alkali stress (AS). A total of 77 metabolites were identified in this study, and the numbers in the figure indicate the numbers of metabolites with no significant difference in their contents for each comparison
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4492011&req=5

Fig4: Global comparison of metabolic profiles in leaves and roots under no salinity stress (CK), salt stress (SS), and alkali stress (AS). A total of 77 metabolites were identified in this study, and the numbers in the figure indicate the numbers of metabolites with no significant difference in their contents for each comparison
Mentions: Based on the results of PCA and OPLS-DA, the responses of metabolites to salt stress and alkali stress were different in leaves and roots. The response of 11 and 5 metabolites under salt stress and 7 and 36 metabolites under alkali stress remarkably increased and decreased, respectively, in leaves of wheat seedlings (Fig. 4, leaves). Following pre-stress, salt stress caused an increase in levels of glucose, glucose-6-P, fructose-6-P, 3-PGA, and PEP, which are involved in glycolysis, and in levels of fructose, trehalose, proline, valine, isoleucine, and leucine. By contrast, salt stress resulted in a decrease in levels of fumaric acid and malic acid, which are involved in the TCA cycle, and in levels of maltose, shikimic acid, and quinic acid, which are involved in the shikimate pathway. Under alkali stress, the levels of some amino acids and sugars increased, including proline, lysine, sucrose, sorbitol, trehalose, lyxose, and gentiobiose; however, glycolysis was significantly inhibited under alkali stress, thereby decreasing the levels of glucose-6-P, fructose-6-P, and PEP. Furthermore, the TCA cycle, which is associated with glycolysis pathway, was inhibited under alkali stress, as shown by lower citric acid, α-ketoglutaric acid, and fumaric acid levels than the control plants. Shikimate pathway and GABA shunt metabolites were inhibited under alkali stress, resulting in a decrease in shikimic acid, quinic acid, phenylalanine, GABA, and glutamate levels (Table 1).Fig. 4

Bottom Line: High-pH of alkali stress induced the most of phosphate and metal ions to precipitate; as a result, the availability of nutrients significantly declined.These outcomes correspond to specific detrimental effects of a highly pH environment.Alkali stress (at high pH) significantly inhibited photosynthetic rate; thus, sugar production was reduced, N metabolism was limited, amino acid production was reduced, and glycolysis was inhibited.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environment and Sustainable Development in Agriculture (IEDA), Chinese Academy of Agricultural Sciences (CAAS)/Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Beijing, 100081, P.R. China. guor219@yahoo.com.

ABSTRACT

Background: It is well known that salinization (high-pH) has been considered as a major environmental threat to agricultural systems. The aim of this study was to investigate the differences between salt stress and alkali stress in metabolic profiles and nutrient accumulation of wheat; these parameters were also evaluated to determine the physiological adaptive mechanisms by which wheat tolerates alkali stress.

Results: The harmful effect of alkali stress on the growth and photosynthesis of wheat were stronger than those of salt stress. High-pH of alkali stress induced the most of phosphate and metal ions to precipitate; as a result, the availability of nutrients significantly declined. Under alkali stress, Ca sharply increased in roots, however, it decreased under salt stress. In addition, we detected the 75 metabolites that were different among the treatments according to GC-MS analysis, including organic acids, amino acids, sugars/polyols and others. The metabolic data showed salt stress and alkali stress caused different metabolic shifts; alkali stress has a stronger injurious effect on the distribution and accumulation of metabolites than salt stress. These outcomes correspond to specific detrimental effects of a highly pH environment.

Conclusions: Ca had a significant positive correlation with alkali tolerates, and increasing Ca concentration can immediately trigger SOS Na exclusion system and reduce the Na injury. Salt stress caused metabolic shifts toward gluconeogenesis with increased sugars to avoid osmotic stress; energy in roots and active synthesis in leaves were needed by wheat to develop salt tolerance. Alkali stress (at high pH) significantly inhibited photosynthetic rate; thus, sugar production was reduced, N metabolism was limited, amino acid production was reduced, and glycolysis was inhibited.

No MeSH data available.


Related in: MedlinePlus