Limits...
Profiling of spatial metabolite distributions in wheat leaves under normal and nitrate limiting conditions.

Allwood JW, Chandra S, Xu Y, Dunn WB, Correa E, Hopkins L, Goodacre R, Tobin AK, Bowsher CG - Phytochemistry (2015)

Bottom Line: Gas Chromatography-Time of Flight/Mass Spectrometry (GC-TOF/MS) combined with multivariate and univariate analyses, and Bayesian network (BN) analysis, distinguished different tissues and confirmed the physiological switch from high rates of respiration to photosynthesis along the leaf.In plants grown in the presence of nitrate there was reduced levels of a number of sugar metabolites in the leaf base and an increase in maltose levels, possibly reflecting an increase in starch turnover.The value of using this combined metabolomics analysis for further functional investigations in the future are discussed.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK; School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

No MeSH data available.


Related in: MedlinePlus

Soluble and insoluble carbohydrate, protein and free amino acid, changes along the developing wheat leaf. Changes in (a) soluble carbohydrate, (b) insoluble carbohydrate, (c) protein, and (d) total free amino acid pool in relation to cell age along the length of 7 day old primary wheat leaves. Data points represent the mean of a minimum of 5 independent growth studies, sampling at least 5 seedlings per replicate. Error bars show ±SE of the mean.
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f0015: Soluble and insoluble carbohydrate, protein and free amino acid, changes along the developing wheat leaf. Changes in (a) soluble carbohydrate, (b) insoluble carbohydrate, (c) protein, and (d) total free amino acid pool in relation to cell age along the length of 7 day old primary wheat leaves. Data points represent the mean of a minimum of 5 independent growth studies, sampling at least 5 seedlings per replicate. Error bars show ±SE of the mean.

Mentions: The total chlorophyll concentration markedly increased from the leaf base to the tip (Fig. 2a and b). The data are plotted in alternative forms to show how distance along the leaf from the base (Fig. 2a) equates to cell age in hours (Fig. 2b). In subsequent graphs the data are presented against cell age. There is a ‘switch over’ from heterotrophic metabolism, where respiration predominates up until the end of the elongation zone of the leaf (Fig. 2d), to autotrophic metabolism, where photosynthesis predominates towards the leaf tip (Fig. 2c). Photosynthetic activity reaches its maximum at the leaf tip, coinciding with the maximum size and development of the chloroplasts (Figs. 2c, S1). Based on this metabolic distinction, metabolite fingerprinting and profiling of the basal, mid and terminal 20 mm sections of the developing wheat leaf allows a comparison to be made between heterotrophic, ‘semi-autotrophic’ and fully autotrophic metabolism. Basal tissue contains cells up to 24 h old, which includes all the meristematic cells as well as those undergoing elongation. Although they contain some chlorophyll (Fig. 2b) there is no detectable photosynthesis (Fig. 2c) and they are dependent on respiration (Fig. 2d) to supply ATP and reductant for nitrogen assimilation. Carbohydrates are present, with the soluble forms predominating (Fig. 3a and b). The soluble protein concentration (Fig. 3c) showed maximal levels in the youngest cells at the leaf base, rapidly decreasing to a minimum towards the end of the elongation zone (20 h). In the mid-section (60–80 mm from the base) the cells are 70–90 h old and while respiratory activity has decreased (Fig. 2d) they are still developing photosynthetically, reaching 50% of the maximum capacity that is attained at the leaf tip (Fig. 2c). In this region of the leaf the soluble carbohydrate (Fig. 3a), proteins (Fig. 3c) and amino acid pools (Fig. 3d) are beginning to increase. Finally, the tip sections are fully developed, with minimum rates of dark respiration (Fig. 2d) and maximum rates of photosynthesis (Fig. 2c).


Profiling of spatial metabolite distributions in wheat leaves under normal and nitrate limiting conditions.

Allwood JW, Chandra S, Xu Y, Dunn WB, Correa E, Hopkins L, Goodacre R, Tobin AK, Bowsher CG - Phytochemistry (2015)

Soluble and insoluble carbohydrate, protein and free amino acid, changes along the developing wheat leaf. Changes in (a) soluble carbohydrate, (b) insoluble carbohydrate, (c) protein, and (d) total free amino acid pool in relation to cell age along the length of 7 day old primary wheat leaves. Data points represent the mean of a minimum of 5 independent growth studies, sampling at least 5 seedlings per replicate. Error bars show ±SE of the mean.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4518043&req=5

f0015: Soluble and insoluble carbohydrate, protein and free amino acid, changes along the developing wheat leaf. Changes in (a) soluble carbohydrate, (b) insoluble carbohydrate, (c) protein, and (d) total free amino acid pool in relation to cell age along the length of 7 day old primary wheat leaves. Data points represent the mean of a minimum of 5 independent growth studies, sampling at least 5 seedlings per replicate. Error bars show ±SE of the mean.
Mentions: The total chlorophyll concentration markedly increased from the leaf base to the tip (Fig. 2a and b). The data are plotted in alternative forms to show how distance along the leaf from the base (Fig. 2a) equates to cell age in hours (Fig. 2b). In subsequent graphs the data are presented against cell age. There is a ‘switch over’ from heterotrophic metabolism, where respiration predominates up until the end of the elongation zone of the leaf (Fig. 2d), to autotrophic metabolism, where photosynthesis predominates towards the leaf tip (Fig. 2c). Photosynthetic activity reaches its maximum at the leaf tip, coinciding with the maximum size and development of the chloroplasts (Figs. 2c, S1). Based on this metabolic distinction, metabolite fingerprinting and profiling of the basal, mid and terminal 20 mm sections of the developing wheat leaf allows a comparison to be made between heterotrophic, ‘semi-autotrophic’ and fully autotrophic metabolism. Basal tissue contains cells up to 24 h old, which includes all the meristematic cells as well as those undergoing elongation. Although they contain some chlorophyll (Fig. 2b) there is no detectable photosynthesis (Fig. 2c) and they are dependent on respiration (Fig. 2d) to supply ATP and reductant for nitrogen assimilation. Carbohydrates are present, with the soluble forms predominating (Fig. 3a and b). The soluble protein concentration (Fig. 3c) showed maximal levels in the youngest cells at the leaf base, rapidly decreasing to a minimum towards the end of the elongation zone (20 h). In the mid-section (60–80 mm from the base) the cells are 70–90 h old and while respiratory activity has decreased (Fig. 2d) they are still developing photosynthetically, reaching 50% of the maximum capacity that is attained at the leaf tip (Fig. 2c). In this region of the leaf the soluble carbohydrate (Fig. 3a), proteins (Fig. 3c) and amino acid pools (Fig. 3d) are beginning to increase. Finally, the tip sections are fully developed, with minimum rates of dark respiration (Fig. 2d) and maximum rates of photosynthesis (Fig. 2c).

Bottom Line: Gas Chromatography-Time of Flight/Mass Spectrometry (GC-TOF/MS) combined with multivariate and univariate analyses, and Bayesian network (BN) analysis, distinguished different tissues and confirmed the physiological switch from high rates of respiration to photosynthesis along the leaf.In plants grown in the presence of nitrate there was reduced levels of a number of sugar metabolites in the leaf base and an increase in maltose levels, possibly reflecting an increase in starch turnover.The value of using this combined metabolomics analysis for further functional investigations in the future are discussed.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK; School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

No MeSH data available.


Related in: MedlinePlus