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Diurnal dynamics of oxygen and carbon dioxide concentrations in shoots and rhizomes of a perennial in a constructed wetland indicate down-regulation of below ground oxygen consumption

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ABSTRACT

Plants have evolved mechanisms to provide oxygen to their parts in oxygen-free environments like wetland sediments. We measured the diurnal courses of oxygen supply to rhizomes of the common reed, a widespread wetland plant. During the day the below-ground plant parts can rely on ample oxygen, but during the night its supply to rhizomes and roots as well as to the whole assembly of associated microorganisms is limited. The key finding of the study was that during periods of low oxygen supply the whole below-ground biota reduces its respiration. This regulation mechanism helps the biota survive unfavourable periods.

No MeSH data available.


Scatterplot of culm internal oxygen concentration against internal carbon dioxide concentration in the six investigated P. australis plants. For correlation coefficients see Table 4.
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plw025-F2: Scatterplot of culm internal oxygen concentration against internal carbon dioxide concentration in the six investigated P. australis plants. For correlation coefficients see Table 4.

Mentions: The ambient levels of [CO2] at the study site during stable atmospheric conditions reached maximum levels of 0.050–0.063 % around sunrise (05:00 h), which decreased to 0.038 % during the day (06:00–16:00 h) and subsequently increased over 0.04 %. The [CO2] in the culms showed high amplitudes that ranged from 0.32 to 17.5 % (A1; Fig. 1B) and from 0.044 to 3.61 % (A2; Fig. 1C). Maximum internal [CO2] were recorded in the early morning hours and ranged in the inflow zone from 11.1 to 12.2 % (plants In1, In2; Fig. 2) and in the outflow zone from 1.55 to 17.5 % (Out1, Out2: 7.28–10.5 %; Fig. 2; A1: 4.96–17.5 %; A2: 1.55–3.61 %; Fig. 1). Starting with the time of [O2] increase (after 07:30), internal [CO2] decreased to minimum values over midday between 0.40 and 0.52 % in the inflow region (In1, In2) and from 0.04 to 0.94 % in the outflow region (A1, A2, Out1, Out2). After 18:00 h, internal [CO2] increased in all culms up to the latest measurement (21:00 h).Figure 2.


Diurnal dynamics of oxygen and carbon dioxide concentrations in shoots and rhizomes of a perennial in a constructed wetland indicate down-regulation of below ground oxygen consumption
Scatterplot of culm internal oxygen concentration against internal carbon dioxide concentration in the six investigated P. australis plants. For correlation coefficients see Table 4.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940480&req=5

plw025-F2: Scatterplot of culm internal oxygen concentration against internal carbon dioxide concentration in the six investigated P. australis plants. For correlation coefficients see Table 4.
Mentions: The ambient levels of [CO2] at the study site during stable atmospheric conditions reached maximum levels of 0.050–0.063 % around sunrise (05:00 h), which decreased to 0.038 % during the day (06:00–16:00 h) and subsequently increased over 0.04 %. The [CO2] in the culms showed high amplitudes that ranged from 0.32 to 17.5 % (A1; Fig. 1B) and from 0.044 to 3.61 % (A2; Fig. 1C). Maximum internal [CO2] were recorded in the early morning hours and ranged in the inflow zone from 11.1 to 12.2 % (plants In1, In2; Fig. 2) and in the outflow zone from 1.55 to 17.5 % (Out1, Out2: 7.28–10.5 %; Fig. 2; A1: 4.96–17.5 %; A2: 1.55–3.61 %; Fig. 1). Starting with the time of [O2] increase (after 07:30), internal [CO2] decreased to minimum values over midday between 0.40 and 0.52 % in the inflow region (In1, In2) and from 0.04 to 0.94 % in the outflow region (A1, A2, Out1, Out2). After 18:00 h, internal [CO2] increased in all culms up to the latest measurement (21:00 h).Figure 2.

View Article: PubMed Central - PubMed

ABSTRACT

Plants have evolved mechanisms to provide oxygen to their parts in oxygen-free environments like wetland sediments. We measured the diurnal courses of oxygen supply to rhizomes of the common reed, a widespread wetland plant. During the day the below-ground plant parts can rely on ample oxygen, but during the night its supply to rhizomes and roots as well as to the whole assembly of associated microorganisms is limited. The key finding of the study was that during periods of low oxygen supply the whole below-ground biota reduces its respiration. This regulation mechanism helps the biota survive unfavourable periods.

No MeSH data available.