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Sulphur limitation and early sulphur deficiency responses in poplar: significance of gene expression, metabolites, and plant hormones.

Honsel A, Kojima M, Haas R, Frank W, Sakakibara H, Herschbach C, Rennenberg H - J. Exp. Bot. (2011)

Bottom Line: S depletion was applied by a gradual decrease of sulphate availability.Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'.S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression).

View Article: PubMed Central - PubMed

Affiliation: Albert-Ludwigs-University Freiburg, Institute of Forest Botany and Tree Physiology, Freiburg, Germany.

ABSTRACT
The influence of sulphur (S) depletion on the expression of genes related to S metabolism, and on metabolite and plant hormone contents was analysed in young and mature leaves, fine roots, xylem sap, and phloem exudates of poplar (Populus tremula×Populus alba) with special focus on early consequences. S depletion was applied by a gradual decrease of sulphate availability. The observed changes were correlated with sulphate contents. Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'. S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression). During early S deficiency, whole plant distribution of S was impacted, as indicated by increasing expression of the phloem-localized sulphate transporter PtaSULTR1;1 and by decreasing glutathione contents in fine roots, young leaves, mature leaves, and phloem exudates. Furthermore, at 'early S deficiency', expression of microRNA395 (miR395), which targets transcripts of PtaATPS3/4 (ATP sulphurylase) for cleavage, increased. Changes in plant hormone contents were observed at 'early S deficiency' only. Thus, S depletion affects S and plant hormone metabolism of poplar during 'S limitation' and 'early S deficiency' in a time series of events. Despite these consequences, the impact of S depletion on growth of poplar plants appears to be less severe than in Brassicaceae such as Arabidopsis thaliana or Brassica sp.

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Contents of dihydrozeatin riboside (DZR) (1), dihydrozeatin riboside phosphates (DZRPs) (2), and dihydrozeatin-9-N-glucoside (DZ9G) (3) in fine roots (A), young leaves (B), and mature leaves (C) of poplars treated with sulphur depletion and of control plants (day 0). Data presented are the means ±SD of five replicates where each replicate consisted of two pooled plants. Lower case letters indicate significant differences at P < 0.05 between different time points within one tissue. dw, dry weight; n.d., not detected
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fig8: Contents of dihydrozeatin riboside (DZR) (1), dihydrozeatin riboside phosphates (DZRPs) (2), and dihydrozeatin-9-N-glucoside (DZ9G) (3) in fine roots (A), young leaves (B), and mature leaves (C) of poplars treated with sulphur depletion and of control plants (day 0). Data presented are the means ±SD of five replicates where each replicate consisted of two pooled plants. Lower case letters indicate significant differences at P < 0.05 between different time points within one tissue. dw, dry weight; n.d., not detected

Mentions: Several dihydrozeatins were increased in fine roots, young leaves, and mature leaves after 21 d of S depletion. However, the composition of individual dihydrozeatins differed greatly between tissues. In fine roots, dihydrozeatin riboside (DZR) and DZR phosphates (DZRPs) were detected, but DZR was found only at the end of the S depletion treatment (Fig. 8A1–2). Contents of both dihydrozeatins increased with decreasing sulphate contents, although this increase was not statistically significant. Both dihydrozeatins were also increased in young leaves, as was dihydrozeatin 9-N-glucoside (DZ9G) (Fig. 8B1–3). However, contents of all three dihydrozeatins fluctuated strongly during S depletion treatment in young leaves, with peak values after 5 d (DZR and DZRPs) or after 2 d (DZ9G). A comparable pattern was observed for DZ9G in mature leaves where contents of DZ9G were elevated after 5 d and after 21 d of S depletion (Fig. 8C3). Contents of DZR did not change in mature leaves during S depletion (Fig. 8C1), and DZRPs were not detected at all (Fig. 8C2).


Sulphur limitation and early sulphur deficiency responses in poplar: significance of gene expression, metabolites, and plant hormones.

Honsel A, Kojima M, Haas R, Frank W, Sakakibara H, Herschbach C, Rennenberg H - J. Exp. Bot. (2011)

Contents of dihydrozeatin riboside (DZR) (1), dihydrozeatin riboside phosphates (DZRPs) (2), and dihydrozeatin-9-N-glucoside (DZ9G) (3) in fine roots (A), young leaves (B), and mature leaves (C) of poplars treated with sulphur depletion and of control plants (day 0). Data presented are the means ±SD of five replicates where each replicate consisted of two pooled plants. Lower case letters indicate significant differences at P < 0.05 between different time points within one tissue. dw, dry weight; n.d., not detected
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3295385&req=5

fig8: Contents of dihydrozeatin riboside (DZR) (1), dihydrozeatin riboside phosphates (DZRPs) (2), and dihydrozeatin-9-N-glucoside (DZ9G) (3) in fine roots (A), young leaves (B), and mature leaves (C) of poplars treated with sulphur depletion and of control plants (day 0). Data presented are the means ±SD of five replicates where each replicate consisted of two pooled plants. Lower case letters indicate significant differences at P < 0.05 between different time points within one tissue. dw, dry weight; n.d., not detected
Mentions: Several dihydrozeatins were increased in fine roots, young leaves, and mature leaves after 21 d of S depletion. However, the composition of individual dihydrozeatins differed greatly between tissues. In fine roots, dihydrozeatin riboside (DZR) and DZR phosphates (DZRPs) were detected, but DZR was found only at the end of the S depletion treatment (Fig. 8A1–2). Contents of both dihydrozeatins increased with decreasing sulphate contents, although this increase was not statistically significant. Both dihydrozeatins were also increased in young leaves, as was dihydrozeatin 9-N-glucoside (DZ9G) (Fig. 8B1–3). However, contents of all three dihydrozeatins fluctuated strongly during S depletion treatment in young leaves, with peak values after 5 d (DZR and DZRPs) or after 2 d (DZ9G). A comparable pattern was observed for DZ9G in mature leaves where contents of DZ9G were elevated after 5 d and after 21 d of S depletion (Fig. 8C3). Contents of DZR did not change in mature leaves during S depletion (Fig. 8C1), and DZRPs were not detected at all (Fig. 8C2).

Bottom Line: S depletion was applied by a gradual decrease of sulphate availability.Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'.S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression).

View Article: PubMed Central - PubMed

Affiliation: Albert-Ludwigs-University Freiburg, Institute of Forest Botany and Tree Physiology, Freiburg, Germany.

ABSTRACT
The influence of sulphur (S) depletion on the expression of genes related to S metabolism, and on metabolite and plant hormone contents was analysed in young and mature leaves, fine roots, xylem sap, and phloem exudates of poplar (Populus tremula×Populus alba) with special focus on early consequences. S depletion was applied by a gradual decrease of sulphate availability. The observed changes were correlated with sulphate contents. Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'. S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression). During early S deficiency, whole plant distribution of S was impacted, as indicated by increasing expression of the phloem-localized sulphate transporter PtaSULTR1;1 and by decreasing glutathione contents in fine roots, young leaves, mature leaves, and phloem exudates. Furthermore, at 'early S deficiency', expression of microRNA395 (miR395), which targets transcripts of PtaATPS3/4 (ATP sulphurylase) for cleavage, increased. Changes in plant hormone contents were observed at 'early S deficiency' only. Thus, S depletion affects S and plant hormone metabolism of poplar during 'S limitation' and 'early S deficiency' in a time series of events. Despite these consequences, the impact of S depletion on growth of poplar plants appears to be less severe than in Brassicaceae such as Arabidopsis thaliana or Brassica sp.

Show MeSH