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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

Principal component analysis (PCA) score plots showing the metabolomic trajectory of leaves (A1) and roots (A2) of wheat seedlings under no salinity stress (CK), salt stress (SS), and alkali stress (AS). Orthogonal partial least squares discriminant analysis (OPLS-DA) scores showing dose dependence of salinity effects on wheat seedlings: CK vs. SS in leaves (B1) and roots (B2). CK vs. AS in leaves (C1) and roots (C2). SS vs. AS in leaves (D1) and roots (D2)
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Fig3: Principal component analysis (PCA) score plots showing the metabolomic trajectory of leaves (A1) and roots (A2) of wheat seedlings under no salinity stress (CK), salt stress (SS), and alkali stress (AS). Orthogonal partial least squares discriminant analysis (OPLS-DA) scores showing dose dependence of salinity effects on wheat seedlings: CK vs. SS in leaves (B1) and roots (B2). CK vs. AS in leaves (C1) and roots (C2). SS vs. AS in leaves (D1) and roots (D2)

Mentions: The metabolic changes in leaves and roots of wheat seedlings subjected to control, salt stress, and alkali stress treatments were determined through GC–MS to reveal the physiological responses and adaptive strategies of wheat to salinity stress. A significant difference exists in the metabolite profiles between samples under control and salinity stress treatments. A total of 75 metabolites were identified and determined in leaves and roots. Based on the PCA results, a separation of samples under control treatment, salt stress, and alkali stress in leaves and roots (Fig. 3 and Additional files 1 and 2) was observed. The control and salinity treatment samples in leaves and roots were separated by the first principal component (PC1), representing 50.9 % and 73.1 % of the total variation (Figs. 3a and b). Pairwise comparative OPLS-DA was conducted with one orthogonal and one predictive component calculated for all models derived from two classes of samples to obtain detailed information on metabolic alterations under salt and alkali stress and significance of metabolites contributing to the alterations. In this research, OPLS-DA models revealed the separation between samples within control and salinity treatments. The score plots of OPLS-DA results showed clear separation between wheat plants under salt and alkali stress and control plants with good model quality (Fig. 3 B1 and C1; B2 and C2). These differences were also observed in the score plots between salt stress and alkali stress in leaves and roots, respectively (Figs. 3 D1 and 3 D2).Fig. 3


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)

Principal component analysis (PCA) score plots showing the metabolomic trajectory of leaves (A1) and roots (A2) of wheat seedlings under no salinity stress (CK), salt stress (SS), and alkali stress (AS). Orthogonal partial least squares discriminant analysis (OPLS-DA) scores showing dose dependence of salinity effects on wheat seedlings: CK vs. SS in leaves (B1) and roots (B2). CK vs. AS in leaves (C1) and roots (C2). SS vs. AS in leaves (D1) and roots (D2)
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: Principal component analysis (PCA) score plots showing the metabolomic trajectory of leaves (A1) and roots (A2) of wheat seedlings under no salinity stress (CK), salt stress (SS), and alkali stress (AS). Orthogonal partial least squares discriminant analysis (OPLS-DA) scores showing dose dependence of salinity effects on wheat seedlings: CK vs. SS in leaves (B1) and roots (B2). CK vs. AS in leaves (C1) and roots (C2). SS vs. AS in leaves (D1) and roots (D2)
Mentions: The metabolic changes in leaves and roots of wheat seedlings subjected to control, salt stress, and alkali stress treatments were determined through GC–MS to reveal the physiological responses and adaptive strategies of wheat to salinity stress. A significant difference exists in the metabolite profiles between samples under control and salinity stress treatments. A total of 75 metabolites were identified and determined in leaves and roots. Based on the PCA results, a separation of samples under control treatment, salt stress, and alkali stress in leaves and roots (Fig. 3 and Additional files 1 and 2) was observed. The control and salinity treatment samples in leaves and roots were separated by the first principal component (PC1), representing 50.9 % and 73.1 % of the total variation (Figs. 3a and b). Pairwise comparative OPLS-DA was conducted with one orthogonal and one predictive component calculated for all models derived from two classes of samples to obtain detailed information on metabolic alterations under salt and alkali stress and significance of metabolites contributing to the alterations. In this research, OPLS-DA models revealed the separation between samples within control and salinity treatments. The score plots of OPLS-DA results showed clear separation between wheat plants under salt and alkali stress and control plants with good model quality (Fig. 3 B1 and C1; B2 and C2). These differences were also observed in the score plots between salt stress and alkali stress in leaves and roots, respectively (Figs. 3 D1 and 3 D2).Fig. 3

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